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  • Write your Tests in RSpec with IronRuby

    - by kazimanzurrashid
    [Note: This is not a continuation of my previous post, treat it as an experiment out in the wild. ] Lets consider the following class, a fictitious Fund Transfer Service: public class FundTransferService : IFundTransferService { private readonly ICurrencyConvertionService currencyConvertionService; public FundTransferService(ICurrencyConvertionService currencyConvertionService) { this.currencyConvertionService = currencyConvertionService; } public void Transfer(Account fromAccount, Account toAccount, decimal amount) { decimal convertionRate = currencyConvertionService.GetConvertionRate(fromAccount.Currency, toAccount.Currency); decimal convertedAmount = convertionRate * amount; fromAccount.Withdraw(amount); toAccount.Deposit(convertedAmount); } } public class Account { public Account(string currency, decimal balance) { Currency = currency; Balance = balance; } public string Currency { get; private set; } public decimal Balance { get; private set; } public void Deposit(decimal amount) { Balance += amount; } public void Withdraw(decimal amount) { Balance -= amount; } } We can write the spec with MSpec + Moq like the following: public class When_fund_is_transferred { const decimal ConvertionRate = 1.029m; const decimal TransferAmount = 10.0m; const decimal InitialBalance = 100.0m; static Account fromAccount; static Account toAccount; static FundTransferService fundTransferService; Establish context = () => { fromAccount = new Account("USD", InitialBalance); toAccount = new Account("CAD", InitialBalance); var currencyConvertionService = new Moq.Mock<ICurrencyConvertionService>(); currencyConvertionService.Setup(ccv => ccv.GetConvertionRate(Moq.It.IsAny<string>(), Moq.It.IsAny<string>())).Returns(ConvertionRate); fundTransferService = new FundTransferService(currencyConvertionService.Object); }; Because of = () => { fundTransferService.Transfer(fromAccount, toAccount, TransferAmount); }; It should_decrease_from_account_balance = () => { fromAccount.Balance.ShouldBeLessThan(InitialBalance); }; It should_increase_to_account_balance = () => { toAccount.Balance.ShouldBeGreaterThan(InitialBalance); }; } and if you run the spec it will give you a nice little output like the following: When fund is transferred » should decrease from account balance » should increase to account balance 2 passed, 0 failed, 0 skipped, took 1.14 seconds (MSpec). Now, lets see how we can write exact spec in RSpec. require File.dirname(__FILE__) + "/../FundTransfer/bin/Debug/FundTransfer" require "spec" require "caricature" describe "When fund is transferred" do Convertion_Rate = 1.029 Transfer_Amount = 10.0 Initial_Balance = 100.0 before(:all) do @from_account = FundTransfer::Account.new("USD", Initial_Balance) @to_account = FundTransfer::Account.new("CAD", Initial_Balance) currency_convertion_service = Caricature::Isolation.for(FundTransfer::ICurrencyConvertionService) currency_convertion_service.when_receiving(:get_convertion_rate).with(:any, :any).return(Convertion_Rate) fund_transfer_service = FundTransfer::FundTransferService.new(currency_convertion_service) fund_transfer_service.transfer(@from_account, @to_account, Transfer_Amount) end it "should decrease from account balance" do @from_account.balance.should be < Initial_Balance end it "should increase to account balance" do @to_account.balance.should be > Initial_Balance end end I think the above code is self explanatory, treat the require(line 1- 4) statements as the add reference of our visual studio projects, we are adding all the required libraries with this statement. Next, the describe which is a RSpec keyword. The before does exactly the same as NUnit's Setup or MsTest’s TestInitialize attribute, but in the above we are using before(:all) which acts as ClassInitialize of MsTest, that means it will be executed only once before all the test methods. In the before(:all) we are first instantiating the from and to accounts, it is same as creating with the full name (including namespace)  like fromAccount = new FundTransfer.Account(.., ..), next, we are creating a mock object of ICurrencyConvertionService, check that for creating the mock we are not using the Moq like the MSpec version. This is somewhat an interesting issue of IronRuby or maybe the DLR, it seems that it is not possible to use the lambda expression that most of the mocking tools uses in arrange phase in Iron Ruby, like: currencyConvertionService.Setup(ccv => ccv.GetConvertionRate(Moq.It.IsAny<string>(), Moq.It.IsAny<string>())).Returns(ConvertionRate); But the good news is, there is already an excellent mocking tool called Caricature written completely in IronRuby which we can use to mock the .NET classes. May be all the mocking tool providers should give some thought to add the support for the DLR, so that we can use the tool that we are already familiar with. I think the rest of the code is too simple, so I am skipping the explanation. Now, the last thing, how we are going to run it with RSpec, lets first install the required gems. Open you command prompt and type the following: igem sources -a http://gems.github.com This will add the GitHub as gem source. Next type: igem install uuidtools caricature rspec and at last we have to create a batch file so that we can execute it in the Notepad++, create a batch like in the IronRuby bin directory like my previous post and put the following in that batch file: @echo off cls call spec %1 --format specdoc pause Next, add a run menu and shortcut in the Notepad++ like my previous post. Now when we run it it will show the following output: When fund is transferred - should decrease from account balance - should increase to account balance Finished in 0.332042 seconds 2 examples, 0 failures Press any key to continue . . . You will complete code of this post in the bottom. That's it for today. Download: RSpecIntegration.zip

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  • Dynamic Bursting ... no really!

    - by Tim Dexter
    If any of you have seen me or my colleagues present BI Publisher to you then we have hopefully mentioned 'bursting.' You may have even seen a demo where we talk about being able to take a batch of data, say invoices. Then split them by some criteria, say customer id; format them with a template; generate the output and then deliver the documents to the recipients with a click. We and especially I, always say this can be completely dynamic! By this I mean, that you could store customer preferences in a database. What layout would each customer like; what output format they would like and how they would like the document delivered. We (I) talk a good talk, but typically don't do the walk in a demo. We hard code everything in the bursting query or bursting control file to get the concept across. But no more peeps! I have finally put together a dynamic bursting demo! Its been minutes in the making but its been tough to find those minutes! Read on ... It's nothing amazing in terms of making the burst dynamic. I created a CUSTOMER_PREFS table with some simple UI in an APEX application so that I can maintain their requirements. In EBS you have descriptive flexfields that could do the same thing or probably even 'contact' fields to store most of the info. Here's my table structure: Name                           Type ------------------------------ -------- CUSTOMER_ID                    NUMBER(6) TEMPLATE_TYPE                  VARCHAR2(20) TEMPLATE_NAME                  VARCHAR2(120) OUTPUT_FORMAT                  VARCHAR2(20) DELIVERY_CHANNEL               VARCHAR2(50) EMAIL                          VARCHAR2(255) FAX                            VARCHAR2(20) ATTACH                         VARCHAR2(20) FILE_LOC                       VARCHAR2(255) Simple enough right? Just need CUSTOMER_ID as the key for the bursting engine to join it to the customer data at burst time. I have not covered the full delivery options, just email, fax and file location. Remember, its a demo people :0) However the principal is exactly the same for each delivery type. They each have a set of attributes that need to be provided and you will need to handle that in your bursting query. On a side note, in EBS, you use a bursting control file, you can apply the same principals that I'm laying out here you just need to get the customer bursting info into the XML data stream so that you can refer to it in the control file using XPATH expressions. Next, we need to look up what attributes or parameters are required for each delivery method. that can be found in the documentation here.  Now we know the combinations of parameters and delivery methods we can construct the query using a series a decode statements: select distinct cp.customer_id "KEY", cp.template_name TEMPLATE, cp.template_type TEMPLATE_FORMAT, 'en-US' LOCALE, cp.output_format OUTPUT_FORMAT, 'false' SAVE_FORMAT, cp.delivery_channel DEL_CHANNEL, decode(cp.delivery_channel,'FILE', cp.file_loc , 'EMAIL', cp.email , 'FAX', cp.fax) PARAMETER1, decode(cp.delivery_channel,'FILE', c.cust_last_name||'_orders.pdf' ,'EMAIL','[email protected]' ,'FAX', 'faxserver.com') PARAMETER2, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','[email protected]' ,'FAX', null) PARAMETER3, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','Your current orders' ,'FAX',NULL) PARAMETER4, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','Please find attached a copy of your current orders with BI Publisher, Inc' ,'FAX',NULL) PARAMETER5, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','false' ,'FAX',NULL) PARAMETER6, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','[email protected]' ,'FAX',NULL) PARAMETER7 from cust_prefs cp, customers c, orders_view ov where cp.customer_id = c.customer_id and cp.customer_id = ov.customer_id order by cp.customer_id Pretty straightforward, just need to test, test, test, the query and ensure it's bringing back the correct data based on each customers preferences. Notice the NULL values for parameters that are not relevant for a given delivery channel. You should end up with bursting control data that the bursting engine can use:  Now, your users can run the burst and documents will be formatted, generated and delivered based on the customer prefs. If you're interested in the example, I have used the sample OE schema data for the base report. The report files and CUST_PREFS table are zipped up here. The zip contains the data model (.xdmz), the report and templates (.xdoz) and the sql scripts to create and load data to the CUST_PREFS table.  Once you load the report into the catalog, you'll need to create the OE data connection and point the data model at it. You'll probably need to re-point the report to the data model too. Happy Bursting!

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  • T-SQL Tuesday #21 - Crap!

    - by Most Valuable Yak (Rob Volk)
    Adam Machanic's (blog | twitter) ever popular T-SQL Tuesday series is being held on Wednesday this time, and the topic is… SHIT CRAP. No, not fecal material.  But crap code.  Crap SQL.  Crap ideas that you thought were good at the time, or were forced to do due (doo-doo?) to lack of time. The challenge for me is to look back on my SQL Server career and find something that WASN'T crap.  Well, there's a lot that wasn't, but for some reason I don't remember those that well.  So the additional challenge is to pick one particular turd that I really wish I hadn't squeezed out.  Let's see if this outline fits the bill: An ETL process on text files; That had to interface between SQL Server and an AS/400 system; That didn't use SSIS (should have) or BizTalk (ummm, no) but command-line scripting, using Unix utilities(!) via: xp_cmdshell; That had to email reports and financial data, some of it sensitive Yep, the stench smell is coming back to me now, as if it was yesterday… As to why SSIS and BizTalk were not options, basically I didn't know either of them well enough to get the job done (and I still don't).  I also had a strict deadline of 3 days, in addition to all the other responsibilities I had, so no time to learn them.  And seeing how screwed up the rest of the process was: Payment files from multiple vendors in multiple formats; Sent via FTP, PGP encrypted email, or some other wizardry; Manually opened/downloaded and saved to a particular set of folders (couldn't change this); Once processed, had to be placed BACK in the same folders with the original archived; x2 divisions that had to run separately; Plus an additional vendor file in another format on a completely different schedule; So that they could be MANUALLY uploaded into the AS/400 system (couldn't change this either, even if it was technically possible) I didn't feel so bad about the solution I came up with, which was naturally: Copy the payment files to the local SQL Server drives, using xp_cmdshell Run batch files (via xp_cmdshell) to parse the different formats using sed, a Unix utility (this was before Powershell) Use other Unix utilities (join, split, grep, wc) to process parsed files and generate metadata (size, date, checksum, line count) Run sqlcmd to execute a stored procedure that passed the parsed file names so it would bulk load the data to do a comparison bcp the compared data out to ANOTHER text file so that I could grep that data out of the original file Run another stored procedure to import the matched data into SQL Server so it could process the payments, including file metadata Process payment batches and log which division and vendor they belong to Email the payment details to the finance group (since it was too hard for them to run a web report with the same data…which they ran anyway to compare the emailed file against…which always matched, surprisingly) Email another report showing unmatched payments so they could manually void them…about 3 months afterward All in "Excel" format, using xp_sendmail (SQL 2000 system) Copy the unmatched data back to the original folder locations, making sure to match the file format exactly (if you've ever worked with ACH files, you'll understand why this sucked) If you're one of the 10 people who have read my blog before, you know that I love the DOS "for" command.  Like passionately.  Like fairy-tale love.  So my batch files were riddled with for loops, nested within other for loops, that called other batch files containing for loops.  I think there was one section that had 4 or 5 nested for commands.  It was wrong, disturbed, and completely un-maintainable by anyone, even myself.  Months, even a year, after I left the company I got calls from someone who had to make a minor change to it, and they called me to talk them out of spraying the office with an AK-47 after looking at this code.  (for you Star Trek TOS fans) The funniest part of this, well, one of the funniest, is that I made the deadline…sort of, I was only a day late…and the DAMN THING WORKED practically unchanged for 3 years.  Most of the problems came from the manual parts of the overall process, like forgetting to decrypt the files, or missing/late files, or saved to the wrong folders.  I'm definitely not trying to toot my own horn here, because this was truly one of the dumbest, crappiest solutions I ever came up with.  Fortunately as far as I know it's no longer in use and someone has written a proper replacement.  Today I would knuckle down and do it in SSIS or Powershell, even if it took me weeks to get it right. The real lesson from this crap code is to make things MAINTAINABLE and UNDERSTANDABLE.  sed scripting regular expressions doesn't fit that criteria in any way.  If you ever find yourself under pressure to do something fast at all costs, DON'T DO IT.  Stop and consider long-term maintainability, not just for yourself but for others on your team.  If you can't explain the basic approach in under 5 minutes, it ultimately won't succeed.  And while you may love to leave all that crap behind, it may follow you anyway, and you'll step in it again.   P.S. - if you're wondering about all the manual stuff that couldn't be changed, it was because the entire process had gone through Six Sigma, and was deemed the best possible way.  Phew!  Talk about stink!

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  • So what are zones really?

    - by Bertrand Le Roy
    There is a (not so) particular kind of shape in Orchard: zones. Functionally, zones are places where other shapes can render. There are top-level zones, the ones defined on Layout, where widgets typically go, and there are local zones that can be defined anywhere. These local zones are what you target in placement.info. Creating a zone is easy because it really is just an empty shape. Most themes include a helper for it: Func<dynamic, dynamic> Zone = x => Display(x); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } With this helper, you can create a zone by simply writing: @Zone(Model.Header) .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Let's deconstruct what's happening here with that weird Lambda. In the Layout template where we are working, the Model is the Layout shape itself, so Model.Header is really creating a new Header shape under Layout, or getting a reference to it if it already exists. The Zone function is then called on that object, which is equivalent to calling Display. In other words, you could have just written the following to get the exact same effect: @Display(Model.Header) The Zone helper function only exists to make the intent very explicit. Now here's something interesting: while this works in the Layout template, you can also make it work from any deeper-nested template and still create top-level zones. The difference is that wherever you are, Model is not the layout anymore so you need to access it in a different way: @Display(WorkContext.Layout.Header) This is still doing the exact same thing as above. One thing to know is that for top-level zones to be usable from the widget editing UI, you need one more thing, which is to specify it in the theme's manifest: Name: Contoso Author: The Orchard Team Description: A subtle and simple CMS themeVersion: 1.1 Tags: business, cms, modern, simple, subtle, product, service Website: http://www.orchardproject.net Zones: Header, Navigation, HomeFeaturedImage, HomeFeaturedHeadline, Messages, Content, ContentAside, TripelFirst, TripelSecond, TripelThird, Footer Local zones are just ordinary shapes like global zones, the only difference being that they are created on a deeper shape than layout. For example, in Content.cshtml, you can find our good old code fro creating a header zone: @Display(Model.Header) The difference here is that Model is no longer the Layout shape, so that zone will be local. The name of that local zone is what you specify in placement.info, for example: <Place Parts_Common_Metadata_Summary="Header:1"/> Now here's the really interesting part: zones do not even know that they are zones, and in fact any shape can be substituted. That means that if you want to add new shapes to the shape that some part has been emitting from its driver for example, you can absolutely do that. And because zones are so barebones as shapes go, they can be created the first time they are accessed. This is what enables us to add shapes into a zone before the code that you would think creates it has even run. For example, in the Layout.cshtml template in TheThemeMachine, the BadgeOfHonor shape is being injected into the Footer zone on line 47, even though that zone will really be "created" on line 168.

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  • College Courses through distance learning

    - by Matt
    I realize this isn't really a programming question, but didn't really know where to post this in the stackexchange and because I am a computer science major i thought id ask here. This is pretty unique to the programmer community since my degree is about 95% programming. I have 1 semester left, but i work full time. I would like to finish up in December, but to make things easier i like to take online classes whenever I can. So, my question is does anyone know of any colleges that offer distance learning courses for computer science? I have been searching around and found a few potential classes, but not sure yet. I would like to gather some classes and see what i can get approval for. Class I need: Only need one C SC 437 Geometric Algorithms C SC 445 Algorithms C SC 473 Automata Only need one C SC 452 Operating Systems C SC 453 Compilers/Systems Software While i only need of each of the above courses i still need to take two more electives. These also have to be upper 400 level classes. So i can take multiple in each category. Some other classes I can take are: CSC 447 - Green Computing CSC 425 - Computer Networking CSC 460 - Database Design CSC 466 - Computer Security I hoping to take one or two of these courses over the summer. If not, then online over the regular semester would be ok too. Any help in helping find these classes would be awesome. Maybe you went to a college that offered distance learning. Some of these classes may be considered to be graduate courses too. Descriptions are listed below if you need. Thanks! Descriptions Computer Security This is an introductory course covering the fundamentals of computer security. In particular, the course will cover basic concepts of computer security such as threat models and security policies, and will show how these concepts apply to specific areas such as communication security, software security, operating systems security, network security, web security, and hardware-based security. Computer Networking Theory and practice of computer networks, emphasizing the principles underlying the design of network software and the role of the communications system in distributed computing. Topics include routing, flow and congestion control, end-to-end protocols, and multicast. Database Design Functions of a database system. Data modeling and logical database design. Query languages and query optimization. Efficient data storage and access. Database access through standalone and web applications. Green Computing This course covers fundamental principles of energy management faced by designers of hardware, operating systems, and data centers. We will explore basic energy management option in individual components such as CPUs, network interfaces, hard drives, memory. We will further present the energy management policies at the operating system level that consider performance vs. energy saving tradeoffs. Finally we will consider large scale data centers where energy management is done at multiple layers from individual components in the system to shutting down entries subset of machines. We will also discuss energy generation and delivery and well as cooling issues in large data centers. Compilers/Systems Software Basic concepts of compilation and related systems software. Topics include lexical analysis, parsing, semantic analysis, code generation; assemblers, loaders, linkers; debuggers. Operating Systems Concepts of modern operating systems; concurrent processes; process synchronization and communication; resource allocation; kernels; deadlock; memory management; file systems. Algorithms Introduction to the design and analysis of algorithms: basic analysis techniques (asymptotics, sums, recurrences); basic design techniques (divide and conquer, dynamic programming, greedy, amortization); acquiring an algorithm repertoire (sorting, median finding, strong components, spanning trees, shortest paths, maximum flow, string matching); and handling intractability (approximation algorithms, branch and bound). Automata Introduction to models of computation (finite automata, pushdown automata, Turing machines), representations of languages (regular expressions, context-free grammars), and the basic hierarchy of languages (regular, context-free, decidable, and undecidable languages). Geometric Algorithms The study of algorithms for geometric objects, using a computational geometry approach, with an emphasis on applications for graphics, VLSI, GIS, robotics, and sensor networks. Topics may include the representation and overlaying of maps, finding nearest neighbors, solving linear programming problems, and searching geometric databases.

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  • Introducing jLight &ndash; Talking to the DOM using Silverlight and jQuery.

    - by Timmy Kokke
    Introduction With the recent news about Silverlight on the Windows Phone and all the great Out-Of-Browser features in the upcoming Silverlight 4 you almost forget Silverlight is a browser plugin. It most often runs in a web browser and often as a control. In many cases you need to communicate with the browser to get information about textboxes, events or details about the browser itself. To do this you can use JavaScript from Silverlight. Although Silverlight works the same on every browser, JavaScript does not and it won’t be long before problems arise. To overcome differences in browser I like to use jQuery. The only downside of doing this is that there’s a lot more code needed that you would normally use when you write jQuery in JavaScript. Lately, I had to catch changes is the browser scrollbar and act to the new position. I also had to move the scrollbar when the user dragged around in the Silverlight application. With jQuery it was peanuts to get and set the right attributes, but I found that I had to write a lot of code on Silverlight side.  With a few refactoring I had a separated out the plumbing into a new class and could call only a few methods on that to get the same thing done. The idea for jLight was born. jLight vs. jQuery The main purpose of jLight is to take the ease of use of jQuery and bring it into Silverlight for handling DOM interaction. For example, to change the text color of a DIV to red, in jQuery you would write: jQuery("div").css("color","red"); In jLight the same thing looks like so: jQuery.Select("div").Css("color","red");   Another example. To change the offset in of the last SPAN you could write this in jQuery : jQuery("span:last").offset({left : 10, top : 100});   In jLight this would do the same: jQuery.Select("span:last").Offset(new {left = 10, top = 100 });   Callbacks Nothing too special so far. To get the same thing done using the “normal” HtmlPage.Window.Eval, it wouldn’t require too much effort. But to wire up a handler for events from the browser it’s a whole different story. Normally you need to register ScriptMembers, ScriptableTypes or write some code in JavaScript. jLight takes care of the plumbing and provide you with an simple interface in the same way jQuery would. If you would like to handle the scroll event of the BODY of your html page, you’ll have to bind the event using jQuery and have a function call back to a registered function in Silverlight. In the example below I assume there’s a method “SomeMethod” and it is registered as a ScriptableObject as “RegisteredFromSilverlight” from Silverlight.   jQuery("body:first").scroll(function() { var sl = document.getElementbyId("SilverlightControl"); sl.content.RegisteredFromSilverlight.SomeMethod($(this)); });       Using jLight  in Silverlight the code would be even simpler. The registration of RegisteredFromSilverlight  as ScriptableObject can be omitted.  Besides that, you don’t have to write any JavaScript or evaluate strings with JavaScript.   jQuery.Select("body:first").scroll(SomeMethod);   Lambdas Using a lambda in Silverlight can make it even simpler.  Each is the jQuery equivalent of foreach in C#. It calls a function for every element found by jQuery. In this example all INPUT elements of the text type are selected. The FromObject method is used to create a jQueryObject from an object containing a ScriptObject. The Val method from jQuery is used to get the value of the INPUT elements.   jQuery.Select("input:text").Each((element, index) => { textBox1.Text += jQueryObject.FromObject(element).Val(); return null; });   Ajax One thing jQuery is often used for is making Ajax calls. Making calls to services to external services can be done from Silverlight, but as easy as using jQuery. As an example I would like to show how jLight does this. Below is the entire code behind. It searches my name on twitter and shows the result. This example can be found in the source of the project. The GetJson method passes a Silverlight JsonValue to a callback. This callback instantiates Twit objects and adds them to a ListBox called TwitList.   public partial class DemoPage2 : UserControl { public DemoPage2() { InitializeComponent(); jQuery.Load(); }   private void CallButton_Click(object sender, RoutedEventArgs e) { jQuery.GetJson("http://search.twitter.com/search.json?lang=en&q=sorskoot", Done); }   private void Done(JsonValue arg) { var tweets = new List<Twit>(); foreach (JsonObject result in arg["results"]) { tweets.Add(new Twit() { Text = (string)result["text"], Image = (string)result["profile_image_url"], User = (string)result["from_user"] } ); } TwitList.ItemsSource = tweets; } }   public class Twit { public string User { get; set; } public string Image { get; set; } public string Text { get; set; } }   Conclusion Although jLight is still in development it can be used already.There isn’t much documentation yet, but if you know jQuery jLight isn’t very hard to use.  If you would like to try it, please let me know what you think and report any problems you run in to. jLight can be found at:   http://jlight.codeplex.com

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  • Blog Buzz - Devoxx 2011

    - by Janice J. Heiss
    Some day I will make it to Devoxx – for now, I’m content to vicariously follow the blogs of attendees and pick up on what’s happening.  I’ve been doing more blog "fishing," looking for the best commentary on 2011 Devoxx. There’s plenty of food for thought – and the ideas are not half-baked.The bloggers are out in full, offering useful summaries and commentary on Devoxx goings-on.Constantin Partac, a Java developer and a member of Transylvania JUG, a community from Cluj-Napoca/Romania, offers an excellent summary of the Devoxx keynotes. Here’s a sample:“Oracle Opening Keynote and JDK 7, 8, and 9 Presentation•    Oracle is committed to Java and wants to provide support for it on any device.•    JSE 7 for Mac will be released next week.•    Oracle would like Java developers to be involved in JCP, to adopt a JSR and to attend local JUG meetings.•    JEE 7 will be released next year.•    JEE 7 is focused on cloud integration, some of the features are already implemented in glassfish 4 development branch.•    JSE 8 will be release in summer of 2013 due to “enterprise community request” as they can not keep the pace with an 18    month release cycle.•    The main features included in JSE8 are lambda support, project Jigsaw, new Date/Time API, project Coin++ and adding   support for sensors. JSE 9 probably will focus on some of these features:1.    self tuning JVM2.    improved native language integration3.    processing enhancement for big data4.    reification (adding runtime class type info for generic types)5.    unification of primitive and corresponding object classes6.    meta-object protocol in order to use type and methods define in other JVM languages7.    multi-tenancy8.    JVM resource management” Thanks Constantin! Ivan St. Ivanov, of SAP Labs Bulgaria, also commented on the keynotes with a different focus.  He summarizes Henrik Stahl’s look ahead to Java SE 8 and JavaFX 3.0; Cameron Purdy on Java EE and the cloud; celebrated Java Champion Josh Bloch on what’s good and bad about Java; Mark Reinhold’s quick look ahead to Java SE 9; and Brian Goetz on lambdas and default methods in Java SE 8. Here’s St. Ivanov’s account of Josh Bloch’s comments on the pluses of Java:“He started with the virtues of the platform. To name a few:    Tightly specified language primitives and evaluation order – int is always 32 bits and operations are executed always from left  to right, without compilers messing around    Dynamic linking – when you change a class, you need to recompile and rebuild just the jar that has it and not the whole application    Syntax  similarity with C/C++ – most existing developers at that time felt like at home    Object orientations – it was cool at that time as well as functional programming is today    It was statically typed language – helps in faster runtime, better IDE support, etc.    No operator overloading – well, I’m not sure why it is good. Scala has it for example and that’s why it is far better for defining DSLs. But I will not argue with Josh.”It’s worth checking out St. Ivanov’s summary of Bloch’s views on what’s not so great about Java as well. What's Coming in JAX-RS 2.0Marek Potociar, Principal Software Engineer at Oracle and currently specification lead of Java EE RESTful web services API (JAX-RS), blogged on his talk about what's coming in JAX-RS 2.0, scheduled for final release in mid-2012.  Here’s a taste:“Perhaps the most wanted addition to the JAX-RS is the Client API, that would complete the JAX-RS story, that is currently server-side only. In JAX-RS 2.0 we are adding a completely interface-based and fluent client API that blends nicely in with the existing fluent response builder pattern on the server-side. When we started with the client API, the first proposal contained around 30 classes. Thanks to the feedback from our Expert Group we managed to reduce the number of API classes to 14 (2 of them being exceptions)! The resulting is compact while at the same time we still managed to create an API that reflects the method invocation context flow (e.g. once you decide on the target URI and start setting headers on the request, your IDE will not try to offer you a URI setter in the code completion). This is a subtle but very important usability aspect of an API…” Obviously, Devoxx is a great Java conference, one that is hitting this year at a time when much is brewing in the platform and beginning to be anticipated.

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  • Goto for the Java Programming Language

    - by darcy
    Work on JDK 8 is well-underway, but we thought this late-breaking JEP for another language change for the platform couldn't wait another day before being published. Title: Goto for the Java Programming Language Author: Joseph D. Darcy Organization: Oracle. Created: 2012/04/01 Type: Feature State: Funded Exposure: Open Component: core/lang Scope: SE JSR: 901 MR Discussion: compiler dash dev at openjdk dot java dot net Start: 2012/Q2 Effort: XS Duration: S Template: 1.0 Reviewed-by: Duke Endorsed-by: Edsger Dijkstra Funded-by: Blue Sun Corporation Summary Provide the benefits of the time-testing goto control structure to Java programs. The Java language has a history of adding new control structures over time, the assert statement in 1.4, the enhanced for-loop in 1.5,and try-with-resources in 7. Having support for goto is long-overdue and simple to implement since the JVM already has goto instructions. Success Metrics The goto statement will allow inefficient and verbose recursive algorithms and explicit loops to be replaced with more compact code. The effort will be a success if at least twenty five percent of the JDK's explicit loops are replaced with goto's. Coordination with IDE vendors is expected to help facilitate this goal. Motivation The goto construct offers numerous benefits to the Java platform, from increased expressiveness, to more compact code, to providing new programming paradigms to appeal to a broader demographic. In JDK 8, there is a renewed focus on using the Java platform on embedded devices with more modest resources than desktop or server environments. In such contexts, static and dynamic memory footprint is a concern. One significant component of footprint is the code attribute of class files and certain classes of important algorithms can be expressed more compactly using goto than using other constructs, saving footprint. For example, to implement state machines recursively, some parties have asked for the JVM to support tail calls, that is, to perform a complex transformation with security implications to turn a method call into a goto. Such complicated machinery should not be assumed for an embedded context. A better solution is just to expose to the programmer the desired functionality, goto. The web has familiarized users with a model of traversing links among different HTML pages in a free-form fashion with some state being maintained on the side, such as login credentials, to effect behavior. This is exactly the programming model of goto and code. While in the past this has been derided as leading to "spaghetti code," spaghetti is a tasty and nutritious meal for programmers, unlike quiche. The invokedynamic instruction added by JSR 292 exposes the JVM's linkage operation to programmers. This is a low-level operation that can be leveraged by sophisticated programmers. Likewise, goto is a also a low-level operation that should not be hidden from programmers who can use more efficient idioms. Some may object that goto was consciously excluded from the original design of Java as one of the removed feature from C and C++. However, the designers of the Java programming languages have revisited these removals before. The enum construct was also left out only to be added in JDK 5 and multiple inheritance was left out, only to be added back by the virtual extension method methods of Project Lambda. As a living language, the needs of the growing Java community today should be used to judge what features are needed in the platform tomorrow; the language should not be forever bound by the decisions of the past. Description From its initial version, the JVM has had two instructions for unconditional transfer of control within a method, goto (0xa7) and goto_w (0xc8). The goto_w instruction is used for larger jumps. All versions of the Java language have supported labeled statements; however, only the break and continue statements were able to specify a particular label as a target with the onerous restriction that the label must be lexically enclosing. The grammar addition for the goto statement is: GotoStatement: goto Identifier ; The new goto statement similar to break except that the target label can be anywhere inside the method and the identifier is mandatory. The compiler simply translates the goto statement into one of the JVM goto instructions targeting the right offset in the method. Therefore, adding the goto statement to the platform is only a small effort since existing compiler and JVM functionality is reused. Other language changes to support goto include obvious updates to definite assignment analysis, reachability analysis, and exception analysis. Possible future extensions include a computed goto as found in gcc, which would replace the identifier in the goto statement with an expression having the type of a label. Testing Since goto will be implemented using largely existing facilities, only light levels of testing are needed. Impact Compatibility: Since goto is already a keyword, there are no source compatibility implications. Performance/scalability: Performance will improve with more compact code. JVMs already need to handle irreducible flow graphs since goto is a VM instruction.

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  • Using a Predicate as a key to a Dictionary

    - by Tom Hines
    I really love Linq and Lambda Expressions in C#.  I also love certain community forums and programming websites like DaniWeb. A user on DaniWeb posted a question about comparing the results of a game that is like poker (5-card stud), but is played with dice. The question stemmed around determining what was the winning hand.  I looked at the question and issued some comments and suggestions toward a potential answer, but I thought it was a neat homework exercise. [A little explanation] I eventually realized not only could I compare the results of the hands (by name) with a certain construct – I could also compare the values of the individual dice with the same construct. That piece of code eventually became a Dictionary with the KEY as a Predicate<int> and the Value a Func<T> that returns a string from the another structure that contains the mapping of an ENUM to a string.  In one instance, that string is the name of the hand and in another instance, it is a string (CSV) representation of of the digits in the hand. An added benefit is that the digits re returned in the order they would be for a proper poker hand.  For instance the hand 1,2,5,3,1 would be returned as ONE_PAIR (1,1,5,3,2). [Getting to the point] 1: using System; 2: using System.Collections.Generic; 3:   4: namespace DicePoker 5: { 6: using KVP_E2S = KeyValuePair<CDicePoker.E_DICE_POKER_HAND_VAL, string>; 7: public partial class CDicePoker 8: { 9: /// <summary> 10: /// Magical construction to determine the winner of given hand Key/Value. 11: /// </summary> 12: private static Dictionary<Predicate<int>, Func<List<KVP_E2S>, string>> 13: map_prd2fn = new Dictionary<Predicate<int>, Func<List<KVP_E2S>, string>> 14: { 15: {new Predicate<int>(i => i.Equals(0)), PlayerTie},//first tie 16:   17: {new Predicate<int>(i => i > 0), 18: (m => string.Format("Player One wins\n1={0}({1})\n2={2}({3})", 19: m[0].Key, m[0].Value, m[1].Key, m[1].Value))}, 20:   21: {new Predicate<int>(i => i < 0), 22: (m => string.Format("Player Two wins\n2={2}({3})\n1={0}({1})", 23: m[0].Key, m[0].Value, m[1].Key, m[1].Value))}, 24:   25: {new Predicate<int>(i => i.Equals(0)), 26: (m => string.Format("Tie({0}) \n1={1}\n2={2}", 27: m[0].Key, m[0].Value, m[1].Value))} 28: }; 29: } 30: } When this is called, the code calls the Invoke method of the predicate to return a bool.  The first on matching true will have its value invoked. 1: private static Func<DICE_HAND, E_DICE_POKER_HAND_VAL> GetHandEval = dh => 2: map_dph2fn[map_dph2fn.Keys.Where(enm2fn => enm2fn(dh)).First()]; After coming up with this process, I realized (with a little modification) it could be called to evaluate the individual values in the dice hand in the event of a tie. 1: private static Func<List<KVP_E2S>, string> PlayerTie = lst_kvp => 2: map_prd2fn.Skip(1) 3: .Where(x => x.Key.Invoke(RenderDigits(dhPlayerOne).CompareTo(RenderDigits(dhPlayerTwo)))) 4: .Select(s => s.Value) 5: .First().Invoke(lst_kvp); After that, I realized I could now create a program completely without “if” statements or “for” loops! 1: static void Main(string[] args) 2: { 3: Dictionary<Predicate<int>, Action<Action<string>>> main = new Dictionary<Predicate<int>, Action<Action<string>>> 4: { 5: {(i => i.Equals(0)), PlayGame}, 6: {(i => true), Usage} 7: }; 8:   9: main[main.Keys.Where(m => m.Invoke(args.Length)).First()].Invoke(Display); 10: } …and there you have it. :) ZIPPED Project

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  • The JavaOne 2012 Sunday Technical Keynote

    - by Janice J. Heiss
    At the JavaOne 2012 Sunday Technical Keynote, held at the Masonic Auditorium, Mark Reinhold, Chief Architect, Java Platform Group, stated that they were going to do things a bit differently--"rather than 20 minutes of SE, and 20 minutes of FX, and 20 minutes of EE, we're going to mix it up a little," he said. "For much of it, we're going to be showing a single application, to show off some of the great work that's been done in the last year, and how Java can scale well--from the cloud all the way down to some very small embedded devices, and how JavaFX scales right along with it."Richard Bair and Jasper Potts from the JavaFX team demonstrated a JavaOne schedule builder application with impressive navigation, animation, pop-overs, and transitions. They noted that the application runs seamlessly on either Windows or Macs, running Java 7. They then ran the same application on an Ubuntu Linux machine--"it just works," said Blair.The JavaFX duo next put the recently released JavaFX Scene Builder through its paces -- dragging and dropping various image assets to build the application's UI, then fine tuning a CSS file for the finished look and feel. Among many other new features, in the past six months, JavaFX has released support for H.264 and HTTP live streaming, "so you can get all the real media playing inside your JavaFX application," said Bair. And in their developer preview builds of JavaFX 8, they've now split the rendering thread from the UI thread, to better take advantage of multi-core architectures.Next, Brian Goetz, Java Language Architect, explored language and library features planned for Java SE 8, including Lambda expressions and better parallel libraries. These feature changes both simplify code and free-up libraries to more effectively use parallelism. "It's currently still a lot of work to convert an application from serial to parallel," noted Goetz.Reinhold had previously boasted of Java scaling down to "small embedded devices," so Blair and Potts next ran their schedule builder application on a small embedded PandaBoard system with an OMAP4 chip set. Connected to a touch screen, the embedded board ran the same JavaFX application previously seen on the desktop systems, but now running on Java SE Embedded. (The systems can be seen and tried at four of the nearby JavaOne hotels.) Bob Vandette, Java Embedded Architect, then displayed a $25 Rasberry Pi ARM-based system running Java SE Embedded, noting the even greater need for the platform independence of Java in such highly varied embedded processor spaces. Reinhold and Vandetta discussed Project Jigsaw, the planned modularization of the Java SE platform, and its deferral from the Java 8 release to Java 9. Reinhold demonstrated the promise of Jigsaw by running a modularized demo version of the earlier schedule builder application on the resource constrained Rasberry Pi system--although the demo gods were not smiling down, and the application ultimately crashed.Reinhold urged developers to become involved in the Java 8 development process--getting the weekly builds, trying out their current code, and trying out the new features:http://openjdk.java.net/projects/jdk8http://openjdk.java.net/projects/jdk8/spechttp://jdk8.java.netFrom there, Arun Gupta explored Java EE. The primary themes of Java EE 7, Gupta stated, will be greater productivity, and HTML 5 functionality (WebSocket, JSON, and HTML 5 forms). Part of the planned productivity increase of the release will come from a reduction in writing boilerplate code--through the widespread use of dependency injection in the platform, along with default data sources and default connection factories. Gupta noted the inclusion of JAX-RS in the web profile, the changes and improvements found in JMS 2.0, as well as enhancements to Java EE 7 in terms of JPA 2.1 and EJB 3.2. GlassFish 4 is the reference implementation of Java EE 7, and currently includes WebSocket, JSON, JAX-RS 2.0, JMS 2.0, and more. The final release is targeted for Q2, 2013. Looking forward to Java EE 8, Gupta explored how the platform will provide multi-tenancy for applications, modularity based on Jigsaw, and cloud architecture. Meanwhile, Project Avatar is the group's incubator project for designing an end-to-end framework for building HTML 5 applications. Santiago Pericas-Geertsen joined Gupta to demonstrate their "Angry Bids" auction/live-bid/chat application using many of the enhancements of Java EE 7, along with an Avatar HTML 5 infrastructure, and running on the GlassFish reference implementation.Finally, Gupta covered Project Easel, an advanced tooling capability in NetBeans for HTML5. John Ceccarelli, NetBeans Engineering Director, joined Gupta to demonstrate creating an HTML 5 project from within NetBeans--formatting the project for both desktop and smartphone implementations. Ceccarelli noted that NetBeans 7.3 beta will be released later this week, and will include support for creating such HTML 5 project types. Gupta directed conference attendees to: http://glassfish.org/javaone2012 for everything about Java EE and GlassFish at JavaOne 2012.

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  • Access Services in SharePoint Server 2010

    - by Wayne
    Another SharePoint Server 2010 feature which cannot go unnoticed is the Access Services. Access Services is a service in SharePoint Server 2010 that allows administrators to view, edit, and configure a Microsoft access application within a Web Browser. Access Services settings support backup and recovery, regardless of whether there is a UI setting in Central Administration. However, backup and recovery only apply to service-level and administrative-level settings; end-user content from the Access application is not backed up as part of this process. Access Services has Windows PowerShell functionality that can be used to provide the service that uses settings from a previous backup; configure and manage macro and query setting; manage and configure session management; and configure all the global settings of the service. Key Benefits of SharePoint Server Access Services Easier Access to right tools: The enhanced, customizable Ribbon in Access 2010 makes it easy to uncover more commands so you can focus on the end product. The new Microsoft Office BackstageTM view is yet another feature that can help you easily analyze and document your database, share, publish, and customize your Access 2010 experience, all from one convenient location. Helps build database effortlessly and quickly: Out-of-the box templates and reusable components make Access Services the fastest, simplest database solution available. It helps find new pre-built templates which you can start using without customization or select templates created by your peers in the Access online community and customize them to meet your needs. It builds your databases with new modular components. New Application Parts enable you to add a set of common Access components, such as a table and form for task management, to your database in a few simple clicks. Database navigation is now simplified. It creates Navigation Forms and makes your frequently used forms and reports more accessible without writing any code or logic. Create Impactful forms and reports: Whether it's an inventory of your assets or customer sales database, Access 2010 brings the innovative tools you'd expect from Microsoft Office. Access Services easily spot trends and add emphasis to your data. It quickly create coordinating database forms and reports and bring the Web into your database. Obtain a centralized landing pad for your data: Access 2010 offers easy ways to bring your data together and help increase work quality. New technologies help break down barriers so you can share and work together on your databases, making you or your team more efficient and productive. Add automation and complex expressions: If you need a more robust database design, such as preventing record deletion if a specific condition is met or if you need to create calculations to forecast your budget, Access 2010 empowers you to be your own developer. The enhanced Expression Builder greatly simplifies your expression building experience with IntelliSense®. With the revamped Macro Designer, it's now even easier for you to add basic logic to your database. New Data Macros allow you to attach logic to your data, centralizing the logic on the table, not the objects that update your data. Key features of Access Services 2010 - Access database content through a Web browser: Newly added Access Services on Microsoft SharePoint Server 2010 enables you to make your databases available on the Web with new Web databases. Users without an Access client can open Web forms and reports via a browser and changes are automatically synchronized. - Simplify how you access the features you need: The Ribbon, improved in Access 2010, helps you access commands even more quickly by enabling you to customize or create your own tabs. The new Microsoft Office Backstage view replaces the traditional File menu to provide one central, organized location for all of your document management tasks. - Codeless navigation: Use professional looking web-like navigation forms to make frequently used forms and reports more accessible without writing any code or logic. - Easily reuse Access items in other databases: Use Application Parts to add pre-built Access components for common tasks to your database in a few simple clicks. You can also package common database components, such as data entry forms and reports for task management, and reuse them across your organization or other databases. - Simplified formatting: By using Office themes you can create coordinating professional forms and reports across your database. Simply select a familiar and great looking Office theme, or design your own, and apply it to your database. Newly created Access objects will automatically match your chosen theme.

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  • JavaOne Latin America Opening Keynotes

    - by Tori Wieldt
    Originally published on blogs.oracle.com/javaone It was a great first day at JavaOne Brazil, which included the Java Strategy and Java Technical keynotes. Henrik Stahl, Senior Director, Product Management for Java opened the keynotes by saying that this is the third year for JavaOne Latin America. He explained, "You know what they say, the first time doesn't count, the second time is a habit and the third time it's a tradition!" He mentioned that he was thrilled that this is largest JavaOne in Brazil to date, and he wants next year to be larger. He said that Oracle knows Latin America is an important hub for development.  "We continually come back to Latin America because of the dedication the community has with driving the continued innovation for Java," he said. Stahl explained that Oracle and the Java community must continue to innovate and Make the Future Java together. The success of Java depends on three important factors: technological innovation, Oracle as a strong steward of Java, and community participation. "The Latin American Java Community (especially in Brazil) is a shining example of how to be positive contributor to Java," Stahl said. Next, George Saab, VP software dev, Java Platform Group at Oracle, discussed some of the recent and upcoming changes to Java. "In addition to the incremental improvements to Java 7, we have also increased the set of platforms supported by Oracle from Linux, Windows, and Solaris to now also include Mac OS X and Linux/ARM for ARM-based PCs such as the Raspberry Pi and emerging ARM based microservers."  Saab announced that EA builds for Linux ARM Hard Float ABI will be available by the end of the year.  Staffan Friberg, Product Manager, Java Platform Group, provided an overview of some of the language coming in Java 8, including Lambda, remove of PermGen, improved data and time APIs and improved security, Java 8 development is moving along. He reminded the audience that they can go to OpenJDK to see this development being done in real-time, and that there are weekly early access builds of OracleJDK 8 that developers can download and try today. Judson Althoff, Senior Vice President, Worldwide Alliances and Channels and Embedded Sales, was invited to the stage, and the audience was told that "even though he is wearing a suit, he is still pretty technical." Althoff started off with a bang: "The Internet of Things is on a collision course with big data and this is a huge opportunity for developers."  For example, Althoff said, today cars are more a data device than a mechanical device. A car embedded with sensors for fuel efficiency, temperature, tire pressure, etc. can generate a petabyte of data A DAY. There are similar examples in healthcare (patient monitoring and privacy requirements creates a complex data problem) and transportation management (sending a package around the world with sensors for humidity, temperature and light). Althoff then brought on stage representatives from three companies that are successful with Java today, first Axel Hansmann, VP Strategy & Marketing Communications, Cinterion. Mr. Hansmann explained that Cinterion, a market leader in Latin America, enables M2M services with Java. At JavaOne San Francisco, Cinterion launched the EHS5, the smallest 3g solderable module, with Java installed on it. This provides Original Equipment Manufacturers (OEMs) with a cost effective, flexible platform for bringing advanced M2M technology to market.Next, Steve Nelson, Director of Marketing for the Americas, at Freescale explained that Freescale is #1 in Embedded Processors in Wired and Wireless Communications, and #1 in Automotive Semiconductors in the Americas. He said that Java provides a mature, proven platform that is uniquely suited to meet the requirements of almost any type of embedded device. He encouraged University students to get involved in the Freescale Cup, a global competition where student teams build, program, and race a model car around a track for speed.Roberto Franco, SBTVD Forum President, SBTVD, talked about Ginga, a Java-based standard for television in Brazil. He said there are 4 million Ginga TV sets in Brazil, and they expect over 20 million TV sets to be sold by the end of 2014. Ginga is also being adopted in other 11 countries in Latin America. Ginga brings interactive services not only at TV set, but also on other devices such as tablets,  PCs or smartphones, as the main or second screen. "Interactive services is already a reality," he said, ' but in a near future, we foresee interactivity enhanced TV content, convergence with OTT services and a big participation from the audience,  all integrated on TV, tablets, smartphones and second screen devices."Before he left the stage, Nandini Ramani thanked Judson for being part of the Java community and invited him to the next Geek Bike Ride in Brazil. She presented him an official geek bike ride jersey.For the Technical Keynote, a "blue screen of death" appeared. With mock concern, Stephin Chin asked the rest of the presenters if they could go on without slides. What followed was a interesting collection of demos, including JavaFX on a tablet, a look at Project Easel in NetBeans, and even Simon Ritter controlling legos with his brainwaves! Stay tuned for more dispatches.

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  • JavaOne Latin America Opening Keynotes

    - by Tori Wieldt
    It was a great first day at JavaOne Brazil, which included the Java Strategy and Java Technical keynotes. Henrik Stahl, Senior Director, Product Management for Java opened the keynotes by saying that this is the third year for JavaOne Latin America. He explained, "You know what they say, the first time doesn't count, the second time is a habit and the third time it's a tradition!" He mentioned that he was thrilled that this is largest JavaOne in Brazil to date, and he wants next year to be larger. He said that Oracle knows Latin America is an important hub for development.  "We continually come back to Latin America because of the dedication the community has with driving the continued innovation for Java," he said. Stahl explained that Oracle and the Java community must continue to innovate and Make the Future Java together. The success of Java depends on three important factors: technological innovation, Oracle as a strong steward of Java, and community participation. "The Latin American Java Community (especially in Brazil) is a shining example of how to be positive contributor to Java," Stahl said. Next, George Saab, VP software dev, Java Platform Group at Oracle, discussed some of the recent and upcoming changes to Java. "In addition to the incremental improvements to Java 7, we have also increased the set of platforms supported by Oracle from Linux, Windows, and Solaris to now also include Mac OS X and Linux/ARM for ARM-based PCs such as the Raspberry Pi and emerging ARM based microservers."  Saab announced that EA builds for Linux ARM Hard Float ABI will be available by the end of the year.  Staffan Friberg, Product Manager, Java Platform Group, provided an overview of some of the language coming in Java 8, including Lambda, remove of PermGen, improved data and time APIs and improved security, Java 8 development is moving along. He reminded the audience that they can go to OpenJDK to see this development being done in real-time, and that there are weekly early access builds of OracleJDK 8 that developers can download and try today. Judson Althoff, Senior Vice President, Worldwide Alliances and Channels and Embedded Sales, was invited to the stage, and the audience was told that "even though he is wearing a suit, he is still pretty technical." Althoff started off with a bang: "The Internet of Things is on a collision course with big data and this is a huge opportunity for developers."  For example, Althoff said, today cars are more a data device than a mechanical device. A car embedded with sensors for fuel efficiency, temperature, tire pressure, etc. can generate a petabyte of data A DAY. There are similar examples in healthcare (patient monitoring and privacy requirements creates a complex data problem) and transportation management (sending a package around the world with sensors for humidity, temperature and light). Althoff then brought on stage representatives from three companies that are successful with Java today, first Axel Hansmann, VP Strategy & Marketing Communications, Cinterion. Mr. Hansmann explained that Cinterion, a market leader in Latin America, enables M2M services with Java. At JavaOne San Francisco, Cinterion launched the EHS5, the smallest 3g solderable module, with Java installed on it. This provides Original Equipment Manufacturers (OEMs) with a cost effective, flexible platform for bringing advanced M2M technology to market.Next, Steve Nelson, Director of Marketing for the Americas, at Freescale explained that Freescale is #1 in Embedded Processors in Wired and Wireless Communications, and #1 in Automotive Semiconductors in the Americas. He said that Java provides a mature, proven platform that is uniquely suited to meet the requirements of almost any type of embedded device. He encouraged University students to get involved in the Freescale Cup, a global competition where student teams build, program, and race a model car around a track for speed.Roberto Franco, SBTVD Forum President, SBTVD, talked about Ginga, a Java-based standard for television in Brazil. He said there are 4 million Ginga TV sets in Brazil, and they expect over 20 million TV sets to be sold by the end of 2014. Ginga is also being adopted in other 11 countries in Latin America. Ginga brings interactive services not only at TV set, but also on other devices such as tablets,  PCs or smartphones, as the main or second screen. "Interactive services is already a reality," he said, ' but in a near future, we foresee interactivity enhanced TV content, convergence with OTT services and a big participation from the audience,  all integrated on TV, tablets, smartphones and second screen devices."Before he left the stage, Nandini Ramani thanked Judson for being part of the Java community and invited him to the next Geek Bike Ride in Brazil. She presented him an official geek bike ride jersey.For the Technical Keynote, a "blue screen of death" appeared. With mock concern, Stephin Chin asked the rest of the presenters if they could go on without slides. What followed was a interesting collection of demos, including JavaFX on a tablet, a look at Project Easel in NetBeans, and even Simon Ritter controlling legos with his brainwaves! Stay tuned for more dispatches.

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  • ODI 12c - Aggregating Data

    - by David Allan
    This posting will look at the aggregation component that was introduced in ODI 12c. For many ETL tool users this shouldn't be a big surprise, its a little different than ODI 11g but for good reason. You can use this component for composing data with relational like operations such as sum, average and so forth. Also, Oracle SQL supports special functions called Analytic SQL functions, you can use a specially configured aggregation component or the expression component for these now in ODI 12c. In database systems an aggregate transformation is a transformation where the values of multiple rows are grouped together as input on certain criteria to form a single value of more significant meaning - that's exactly the purpose of the aggregate component. In the image below you can see the aggregate component in action within a mapping, for how this and a few other examples are built look at the ODI 12c Aggregation Viewlet here - the viewlet illustrates a simple aggregation being built and then some Oracle analytic SQL such as AVG(EMP.SAL) OVER (PARTITION BY EMP.DEPTNO) built using both the aggregate component and the expression component. In 11g you used to just write the aggregate expression directly on the target, this made life easy for some cases, but it wan't a very obvious gesture plus had other drawbacks with ordering of transformations (agg before join/lookup. after set and so forth) and supporting analytic SQL for example - there are a lot of postings from creative folks working around this in 11g - anything from customizing KMs, to bypassing aggregation analysis in the ODI code generator. The aggregate component has a few interesting aspects. 1. Firstly and foremost it defines the attributes projected from it - ODI automatically will perform the grouping all you do is define the aggregation expressions for those columns aggregated. In 12c you can control this automatic grouping behavior so that you get the code you desire, so you can indicate that an attribute should not be included in the group by, that's what I did in the analytic SQL example using the aggregate component. 2. The component has a few other properties of interest; it has a HAVING clause and a manual group by clause. The HAVING clause includes a predicate used to filter rows resulting from the GROUP BY clause. Because it acts on the results of the GROUP BY clause, aggregation functions can be used in the HAVING clause predicate, in 11g the filter was overloaded and used for both having clause and filter clause, this is no longer the case. If a filter is after an aggregate, it is after the aggregate (not sometimes after, sometimes having).  3. The manual group by clause let's you use special database grouping grammar if you need to. For example Oracle has a wealth of highly specialized grouping capabilities for data warehousing such as the CUBE function. If you want to use specialized functions like that you can manually define the code here. The example below shows the use of a manual group from an example in the Oracle database data warehousing guide where the SUM aggregate function is used along with the CUBE function in the group by clause. The SQL I am trying to generate looks like the following from the data warehousing guide; SELECT channel_desc, calendar_month_desc, countries.country_iso_code,       TO_CHAR(SUM(amount_sold), '9,999,999,999') SALES$ FROM sales, customers, times, channels, countries WHERE sales.time_id=times.time_id AND sales.cust_id=customers.cust_id AND   sales.channel_id= channels.channel_id  AND customers.country_id = countries.country_id  AND channels.channel_desc IN   ('Direct Sales', 'Internet') AND times.calendar_month_desc IN   ('2000-09', '2000-10') AND countries.country_iso_code IN ('GB', 'US') GROUP BY CUBE(channel_desc, calendar_month_desc, countries.country_iso_code); I can capture the source datastores, the filters and joins using ODI's dataset (or as a traditional flow) which enables us to incrementally design the mapping and the aggregate component for the sum and group by as follows; In the above mapping you can see the joins and filters declared in ODI's dataset, allowing you to capture the relationships of the datastores required in an entity-relationship style just like ODI 11g. The mix of ODI's declarative design and the common flow design provides for a familiar design experience. The example below illustrates flow design (basic arbitrary ordering) - a table load where only the employees who have maximum commission are loaded into a target. The maximum commission is retrieved from the bonus datastore and there is a look using employees as the driving table and only those with maximum commission projected. Hopefully this has given you a taster for some of the new capabilities provided by the aggregate component in ODI 12c. In summary, the actions should be much more consistent in behavior and more easily discoverable for users, the use of the components in a flow graph also supports arbitrary designs and the tool (rather than the interface designer) takes care of the realization using ODI's knowledge modules. Interested to know if a deep dive into each component is interesting for folks. Any thoughts? 

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  • JavaOne 2012 Sunday Strategy Keynote

    - by Janice J. Heiss
    At the Sunday Strategy Keynote, held at the Masonic Auditorium, Hasan Rizvi, EVP, Middleware and Java Development, stated that the theme for this year's JavaOne is: “Make the future Java”-- meaning that Java continues in its role as the most popular, complete, productive, secure, and innovative development platform. But it also means, he qualified, the process by which we make the future Java -- an open, transparent, collaborative, and community-driven evolution. "Many of you have bet your businesses and your careers on Java, and we have bet our business on Java," he said.Rizvi detailed the three factors they consider critical to the success of Java--technology innovation, community participation, and Oracle's leadership/stewardship. He offered a scorecard in these three realms over the past year--with OS X and Linux ARM support on Java SE, open sourcing of JavaFX by the end of the year, the release of Java Embedded Suite 7.0 middleware platform, and multiple releases on the Java EE side. The JCP process continues, with new JSR activity, and JUGs show a 25% increase in participation since last year. Oracle, meanwhile, continues its commitment to both technology and community development/outreach--with four regional JavaOne conferences last year in various part of the world, as well as the release of Java Magazine, with over 120,000 current subscribers. Georges Saab, VP Development, Java SE, next reviewed features of Java SE 7--the first major revision to the platform under Oracle's stewardship, which has included near-monthly update releases offering hundreds of fixes, performance enhancements, and new features. Saab indicated that developers, ISVs, and hosting providers have all been rapid adopters of the platform. He also noted that Oracle's entire Fusion middleware stack is supported on SE 7. The supported platforms for SE 7 has also increased--from Windows, Linux, and Solaris, to OS X, Linux ARM, and the emerging ARM micro-server market. "In the last year, we've added as many new platforms for Java, as were added in the previous decade," said Saab.Saab also explored the upcoming JDK 8 release--including Project Lambda, Project Nashorn (a modern implementation of JavaScript running on the JVM), and others. He noted that Nashorn functionality had already been used internally in NetBeans 7.3, and announced that they were planning to contribute the implementation to OpenJDK. Nandini Ramani, VP Development, Java Client, ME and Card, discussed the latest news pertaining to JavaFX 2.0--releases on Windows, OS X, and Linux, release of the FX Scene Builder tool, the JavaFX WebView component in NetBeans 7.3, and an OpenJFX project in OpenJDK. Nandini announced, as of Sunday, the availability for download of JavaFX on Linux ARM (developer preview), as well as Scene Builder on Linux. She noted that for next year's JDK 8 release, JavaFX will offer 3D, as well as third-party component integration. Avinder Brar, Senior Software Engineer, Navis, and Dierk König, Canoo Fellow, next took the stage and demonstrated all that JavaFX offers, with a feature-rich, animation-rich, real-time cargo management application that employs Canoo's just open-sourced Dolphin technology.Saab also explored Java SE 9 and beyond--Jigsaw modularity, Penrose Project for interoperability with OSGi, improved multi-tenancy for Java in the cloud, and Project Sumatra. Phil Rogers, HSA Foundation President and AMD Corporate Fellow, explored heterogeneous computing platforms that combine the CPU and the parallel processor of the GPU into a single piece of silicon and shared memory—a hardware technology driven by such advanced functionalities as HD video, face recognition, and cloud workloads. Project Sumatra is an OpenJDK project targeted at bringing Java to such heterogeneous platforms--with hardware and software experts working together to modify the JVM for these advanced applications and platforms.Ramani next discussed the latest with Java in the embedded space--"the Internet of things" and M2M--declaring this to be "the next IT revolution," with Java as the ideal technology for the ecosystem. Last week, Oracle released Java ME Embedded 3.2 (for micro-contollers and low-power devices), and Java Embedded Suite 7.0 (a middleware stack based on Java SE 7). Axel Hansmann, VP Strategy and Marketing, Cinterion, explored his company's use of Java in M2M, and their new release of EHS5, the world's smallest 3G-capable M2M module, running Java ME Embedded. Hansmaan explained that Java offers them the ability to create a "simple to use, scalable, coherent, end-to-end layer" for such diverse edge devices.Marc Brule, Chief Financial Office, Royal Canadian Mint, also explored the fascinating use-case of JavaCard in his country's MintChip e-cash technology--deployable on smartphones, USB device, computer, tablet, or cloud. In parting, Ramani encouraged developers to download the latest releases of Java Embedded, and try them out.Cameron Purdy, VP, Fusion Middleware Development and Java EE, summarized the latest developments and announcements in the Enterprise space--greater developer productivity in Java EE6 (with more on the way in EE 7), portability between platforms, vendors, and even cloud-to-cloud portability. The earliest version of the Java EE 7 SDK is now available for download--in GlassFish 4--with WebSocket support, better JSON support, and more. The final release is scheduled for April of 2013. Nicole Otto, Senior Director, Consumer Digital Technology, Nike, explored her company's Java technology driven enterprise ecosystem for all things sports, including the NikeFuel accelerometer wrist band. Looking beyond Java EE 7, Purdy mentioned NoSQL database functionality for EE 8, the concurrency utilities (possibly in EE 7), some of the Avatar projects in EE 7, some in EE 8, multi-tenancy for the cloud, supporting SaaS applications, and more.Rizvi ended by introducing Dr. Robert Ballard, oceanographer and National Geographic Explorer in Residence--part of Oracle's philanthropic relationship with the National Geographic Society to fund K-12 education around ocean science and conservation. Ballard is best known for having discovered the wreckage of the Titanic. He offered a fascinating video and overview of the cutting edge technology used in such deep-sea explorations, noting that in his early days, high-bandwidth exploration meant that you’d go down in a submarine and "stick your face up against the window." Now, it's a remotely operated, technology telepresence--"I think of my Hercules vehicle as my equivalent of a Na'vi. When I go beneath the sea, I actually send my spirit." Using high bandwidth satellite links, such amazing explorations can now occur via smartphone, laptop, or whatever platform. Ballard’s team regularly offers live feeds and programming out to schools and the world, spanning 188 countries--with embedding educators as part of the expeditions. It's technology at its finest, inspiring the next-generation of scientists and explorers!

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  • concurrency::index<N> from amp.h

    - by Daniel Moth
    Overview C++ AMP introduces a new template class index<N>, where N can be any value greater than zero, that represents a unique point in N-dimensional space, e.g. if N=2 then an index<2> object represents a point in 2-dimensional space. This class is essentially a coordinate vector of N integers representing a position in space relative to the origin of that space. It is ordered from most-significant to least-significant (so, if the 2-dimensional space is rows and columns, the first component represents the rows). The underlying type is a signed 32-bit integer, and component values can be negative. The rank field returns N. Creating an index The default parameterless constructor returns an index with each dimension set to zero, e.g. index<3> idx; //represents point (0,0,0) An index can also be created from another index through the copy constructor or assignment, e.g. index<3> idx2(idx); //or index<3> idx2 = idx; To create an index representing something other than 0, you call its constructor as per the following 4-dimensional example: int temp[4] = {2,4,-2,0}; index<4> idx(temp); Note that there are convenience constructors (that don’t require an array argument) for creating index objects of rank 1, 2, and 3, since those are the most common dimensions used, e.g. index<1> idx(3); index<2> idx(3, 6); index<3> idx(3, 6, 12); Accessing the component values You can access each component using the familiar subscript operator, e.g. One-dimensional example: index<1> idx(4); int i = idx[0]; // i=4 Two-dimensional example: index<2> idx(4,5); int i = idx[0]; // i=4 int j = idx[1]; // j=5 Three-dimensional example: index<3> idx(4,5,6); int i = idx[0]; // i=4 int j = idx[1]; // j=5 int k = idx[2]; // k=6 Basic operations Once you have your multi-dimensional point represented in the index, you can now treat it as a single entity, including performing common operations between it and an integer (through operator overloading): -- (pre- and post- decrement), ++ (pre- and post- increment), %=, *=, /=, +=, -=,%, *, /, +, -. There are also operator overloads for operations between index objects, i.e. ==, !=, +=, -=, +, –. Here is an example (where no assertions are broken): index<2> idx_a; index<2> idx_b(0, 0); index<2> idx_c(6, 9); _ASSERT(idx_a.rank == 2); _ASSERT(idx_a == idx_b); _ASSERT(idx_a != idx_c); idx_a += 5; idx_a[1] += 3; idx_a++; _ASSERT(idx_a != idx_b); _ASSERT(idx_a == idx_c); idx_b = idx_b + 10; idx_b -= index<2>(4, 1); _ASSERT(idx_a == idx_b); Usage You'll most commonly use index<N> objects to index into data types that we'll cover in future posts (namely array and array_view). Also when we look at the new parallel_for_each function we'll see that an index<N> object is the single parameter to the lambda, representing the (multi-dimensional) thread index… In the next post we'll go beyond being able to represent an N-dimensional point in space, and we'll see how to define the N-dimensional space itself through the extent<N> class. Comments about this post by Daniel Moth welcome at the original blog.

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  • Silverlight Relay Commands

    - by George Evjen
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} I am fairly new at Silverlight development and I usually have an issue that needs research every day. Which I enjoy, since I like the idea of going into a day knowing that I am  going to learn something new. The issue that I am currently working on centers around relay commands. I have a pretty good handle on Relay Commands and how we use them within our applications. <Button Command="{Binding ButtonCommand}" CommandParameter="NewRecruit" Content="New Recruit" /> Here in our xaml we have a button. The button has a Command and a CommandParameter. The command binds to the ButtonCommand that we have in our ViewModel RelayCommand _buttonCommand;         /// <summary>         /// Gets the button command.         /// </summary>         /// <value>The button command.</value>         public RelayCommand ButtonCommand         {             get             {                 if (_buttonCommand == null)                 {                     _buttonCommand = new RelayCommand(                         x => x != null && x.ToString().Length > 0 && CheckCommandAvailable(x.ToString()),                         x => ExecuteCommand(x.ToString()));                 }                 return _buttonCommand;             }         }   In our relay command we then do some checks with a lambda expression. We check if the command  parameter is null, is the length greater than 0 and we have a CheckCommandAvailable method that will tell  us if the button is even enabled. After we check on these three items we then pass the command parameter to an action method. This is all pretty straight forward, the issue that we solved a few days ago centered around having a control that needed to use a Relay Command and this control was a nested control and was using a different DataContext. The example below illustrates how we handled this scenario. In our xaml usercontrol we had to set a name to this control. <Controls3:RadTileViewItem x:Class="RecruitStatusTileView"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"      xmlns:Controls1="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls"      xmlns:Controls2="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Input"      xmlns:Controls3="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Navigation"      mc:Ignorable="d" d:DesignHeight="400" d:DesignWidth="800" Header="{Binding Title,Mode=TwoWay}" MinimizedHeight="100"                             x:Name="StatusView"> Here we are using a telerik RadTileViewItem. We set the name of this control to “StatusView”. In our button control we set our command parameters and commands different than the example above. <HyperlinkButton Content="{Binding BigBoardButtonText, Mode=TwoWay}" CommandParameter="{Binding 'Position.PositionName'}" Command="{Binding ElementName=StatusView, Path=DataContext.BigBoardCommand, Mode=TwoWay}" /> This hyperlink button lives in a ListBox control and this listbox has an ItemSource of PositionSelectors. The Command Parameter is binding to the Position.Position property of that PositionSelectors object. This again is pretty straight forward again. What gets a bit tricky is the Command property in the hyperlink. It is binding to the element name we created in the user control (StatusView) Because this hyperlink is in a listbox and is in the item template it doesn’t have a direct handle on the DataContext that the RadTileViewItem has so we have to make sure it does. We do that by binding to the element name of status view then set the path to DataContext.BigBoardCommand. BigBoardCommand is the name of the RelayCommand in the view model. private RelayCommand _bigBoardCommand = null;         /// <summary>         /// Gets the big board command.         /// </summary>         /// <value>The big board command.</value>         public RelayCommand BigBoardCommand         {             get             {                 if (_bigBoardCommand == null)                 {                     _bigBoardCommand = new RelayCommand(x => true, x => AddToBigBoard(x.ToString()));                 }                 return _bigBoardCommand;             }         } From there we check for true again and then call the action and pass in the parameter that we had as the command parameter. What we are working on now is a bit trickier than this second example. In the above example we are only creating this TileViewItem with this name “StatusView” once. In another part of our application we are generating multiple TileViewItems, so we cannot set the name in the control as we cant have multiple controls with the same name. When we run the application we get an error that reads that the value is out of expected range. My searching has led me to think we cannot have multiple controls with the same name. This is today’s problem and Ill post the solution to this once it is found.

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  • Yes, I did it - Skydiving in Mauritius

    Finally, I did it or better said we did it. Already back in November last year I saw the big billboard advertisement of Skydive Austral Mauritius near Caudan Waterfront in Port Louis and decided for myself that this is going to be the perfect birthday gift for my wife. Simply out of curiosity I would join her tandem jump with a second instructor. Due to her pregnancy of our son I had to be patient... But then finally, her birthday had arrived and on our midnight celebration session I showed her her netbook with the website preloaded. Actually, it was the "perfect" timing... Recovery from her cesarean is fine, local weather conditions are gorgious and the children were under surveillance of my mum - spending her annual holidays on the island. So, after late wake-up in the morning, we packed our stuff and off we went. According to Google Maps direction indication we had to drive for roughly 50km (only) but traffic here in Mauritius is always challenging. The dropzone is at the Zone Industrielle Mon Loisir Sugar Estate near Riviere du Rempart at the northern east coast. Anyways, we were not in a hurry and arrived there shortly after noon. The access road to the airfield are just small down-driven paths through sugar cane fields and according to our daughter "it's bumpy!". True true true... The facilities at Skydive Austral Mauritius are complete except for food. Enough space for parking, easy handling at the reception and a lot to see for the kids. There's even a big terrace with several sets of tables and chairs, small bar for soft drinks, strictly non-alcoholic. The team over there is all welcoming and warm-hearthy! Having the kids with us was no issue at all. Quite the opposite, our daugther was allowed to discover a lot of things than we adults did. Even visiting the small air plane was on the menu for her. Really great stuff! While waiting for our turn we enjoyed watching other people getting ready in the jump gear, taking off with the Cessna, and finally coming back down on the tandem parachute. Actually, the different expressions on their faces was one of the best parts while waiting. Great mental preparation as my wife was getting more anxious about her first jump... {loadposition content_adsense} First, we got some information about the procedures on the plane about how to get seated, tight up with our instructors and how to get ready for the jump off the plane as soon as we arrive the height of 10.000 ft. All well explained and easy to understand after all.Next, we met with our jumpers Chris and Lee aka "Rasta" to get dressed and ready for take-off. Those guys are really cool and relaxed for their job. From that point on, the DVD session / recording for my wife's birthday started and we really had a lot of fun... The difference between that small Cessna and a commercial flight with an Airbus or a Boeing is astronomic! The climb up to 10.000 ft took us roughly 25 minutes and we enjoyed the magnificent view over the turquoise lagunes near Poste de Flacq, Lafayette and Isle d'Ambre on the north-east coast. After flying through the clouds we sun-bathed and looked over "iced-sugar covered" Mauritius. You might have a look at the picture gallery of Skydive Mauritius for better imagination. The moment of truth, or better said, point of no return came after approximately 25 minutes. The door opens, moving into position on the side on top of the wheel and... out! Back flip and free fall! Slight turns and Wooooohooooo! through the clouds... It so amazing and breath-taking! So undescribable! You have to experience this yourself! Some seconds later the parachute opened and we glided smoothly with some turns and spins back down to the dropzone. The rest of the family could hear and see us soon and the landing was easy going. We never had any doubts or fear about our instructors. They did a great job and we are looking forward to book our next job. I might even consider to follow educational classes on skydiving and earn a license. By the way, feel free to get in touch with Skydive Austral Mauritius. Either via contact details on their website or tweeting a little bit with them. Follow the tweets of Chris and fellows on SkydiveAustral.

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  • C# Open Source software that is useful for learning Design Patterns

    - by Fathom Savvy
    In college I took a class in Expert Systems. The language the book taught (CLIPS) was esoteric - Expert Systems: Principles and Programming, Fourth Edition. I remember having a tough time with it. So, after almost failing the class, I needed to create the most awesome Expert System for my final presentation. I chose to create an expert system that would calculate risk analysis for a person's retirement portfolio. In short, the system would provide the services normally performed by one's financial adviser. In other words, based on personality, age, state of the macro economy, and other factors, should one's portfolio be conservative, moderate, or aggressive? In the appendix of the book (or on the CD-ROM), there was this in-depth example program for something unrelated to my presentation. Over my break, I read and re-read every line of that program until I understood it to the letter. Even though it was unrelated, I learned more than I ever could by reading all of the chapters. My presentation turned out to be pretty damn good and I received praises from my professor and classmates. So, the moral of the story is..., by understanding other people's code, you can gain greater insight into a language/paradigm than by reading canonical examples. Still, to this day, I am having trouble with everyday design patterns such as the Factory Pattern. I would like to know if anyone could recommend open source software that would help me understand the Gang of Four design patterns, at the very least. I have read the books, but I'm having trouble writing code for the concepts in the real world. Perhaps, by studying code used in today's real world applications, it might just "click". I realize a piece of software may only implement one kind of design pattern. But, if the pattern is an implementation you think is good for learning, and you know what pattern to look for within the source, I'm hoping you can tell me about it. For example, the System.Linq.Expressions namespace has a good example of the Visitor Pattern. The client calls Expression.Accept(new ExpressionVisitor()), which calls ExpressionVisitor (VisitExtension), which calls back to Expression (VisitChildren), which then calls Expression (Accept) again - wooah, kinda convoluted. The point to note here is that VisitChildren is a virtual method. Both Expression and those classes derived from Expression can implement the VisitChildren method any way they want. This means that one type of Expression can run code that is completely different from another type of derived Expression, even though the ExpressionVisitor class is the same in the Accept method. (As a side note Expression.Accept is also virtual). In the end, the code provides a real world example that you won't get in any book because it's kinda confusing. To summarize, If you know of any open source software that uses a design pattern implementation you were impressed by, please list it here. I'm sure it will help many others besides just me. public class VisitorPatternTest { public void Main() { Expression normalExpr = new Expression(); normalExpr.Accept(new ExpressionVisitor()); Expression binExpr = new BinaryExpression(); binExpr.Accept(new ExpressionVisitor()); } } public class Expression { protected internal virtual Expression Accept(ExpressionVisitor visitor) { return visitor.VisitExtension(this); } protected internal virtual Expression VisitChildren(ExpressionVisitor visitor) { if (!this.CanReduce) { throw Error.MustBeReducible(); } return visitor.Visit(this.ReduceAndCheck()); } public virtual Expression Visit(Expression node) { if (node != null) { return node.Accept(this); } return null; } public Expression ReduceAndCheck() { if (!this.CanReduce) { throw Error.MustBeReducible(); } Expression expression = this.Reduce(); if ((expression == null) || (expression == this)) { throw Error.MustReduceToDifferent(); } if (!TypeUtils.AreReferenceAssignable(this.Type, expression.Type)) { throw Error.ReducedNotCompatible(); } return expression; } } public class BinaryExpression : Expression { protected internal override Expression Accept(ExpressionVisitor visitor) { return visitor.VisitBinary(this); } protected internal override Expression VisitChildren(ExpressionVisitor visitor) { return CreateDummyExpression(); } protected internal Expression CreateDummyExpression() { Expression dummy = new Expression(); return dummy; } } public class ExpressionVisitor { public virtual Expression Visit(Expression node) { if (node != null) { return node.Accept(this); } return null; } protected internal virtual Expression VisitExtension(Expression node) { return node.VisitChildren(this); } protected internal virtual Expression VisitBinary(BinaryExpression node) { return ValidateBinary(node, node.Update(this.Visit(node.Left), this.VisitAndConvert<LambdaExpression>(node.Conversion, "VisitBinary"), this.Visit(node.Right))); } }

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  • Null Values And The T-SQL IN Operator

    - by Jesse
    I came across some unexpected behavior while troubleshooting a failing test the other day that took me long enough to figure out that I thought it was worth sharing here. I finally traced the failing test back to a SELECT statement in a stored procedure that was using the IN t-sql operator to exclude a certain set of values. Here’s a very simple example table to illustrate the issue: Customers CustomerId INT, NOT NULL, Primary Key CustomerName nvarchar(100) NOT NULL SalesRegionId INT NULL   The ‘SalesRegionId’ column contains a number representing the sales region that the customer belongs to. This column is nullable because new customers get created all the time but assigning them to sales regions is a process that is handled by a regional manager on a periodic basis. For the purposes of this example, the Customers table currently has the following rows: CustomerId CustomerName SalesRegionId 1 Customer A 1 2 Customer B NULL 3 Customer C 4 4 Customer D 2 5 Customer E 3   How could we write a query against this table for all customers that are NOT in sales regions 2 or 4? You might try something like this: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE SalesRegionId NOT IN (2,4)   Will this work? In short, no; at least not in the way that you might expect. Here’s what this query will return given the example data we’re working with: CustomerId CustomerName SalesRegionId 1 Customer A 1 5 Customer E 5   I was expecting that this query would also return ‘Customer B’, since that customer has a NULL SalesRegionId. In my mind, having a customer with no sales region should be included in a set of customers that are not in sales regions 2 or 4.When I first started troubleshooting my issue I made note of the fact that this query should probably be re-written without the NOT IN clause, but I didn’t suspect that the NOT IN clause was actually the source of the issue. This particular query was only one minor piece in a much larger process that was being exercised via an automated integration test and I simply made a poor assumption that the NOT IN would work the way that I thought it should. So why doesn’t this work the way that I thought it should? From the MSDN documentation on the t-sql IN operator: If the value of test_expression is equal to any value returned by subquery or is equal to any expression from the comma-separated list, the result value is TRUE; otherwise, the result value is FALSE. Using NOT IN negates the subquery value or expression. The key phrase out of that quote is, “… is equal to any expression from the comma-separated list…”. The NULL SalesRegionId isn’t included in the NOT IN because of how NULL values are handled in equality comparisons. From the MSDN documentation on ANSI_NULLS: The SQL-92 standard requires that an equals (=) or not equal to (<>) comparison against a null value evaluates to FALSE. When SET ANSI_NULLS is ON, a SELECT statement using WHERE column_name = NULL returns zero rows even if there are null values in column_name. A SELECT statement using WHERE column_name <> NULL returns zero rows even if there are nonnull values in column_name. In fact, the MSDN documentation on the IN operator includes the following blurb about using NULL values in IN sub-queries or expressions that are used with the IN operator: Any null values returned by subquery or expression that are compared to test_expression using IN or NOT IN return UNKNOWN. Using null values in together with IN or NOT IN can produce unexpected results. If I were to include a ‘SET ANSI_NULLS OFF’ command right above my SELECT statement I would get ‘Customer B’ returned in the results, but that’s definitely not the right way to deal with this. We could re-write the query to explicitly include the NULL value in the WHERE clause: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE (SalesRegionId NOT IN (2,4) OR SalesRegionId IS NULL)   This query works and properly includes ‘Customer B’ in the results, but I ultimately opted to re-write the query using a LEFT OUTER JOIN against a table variable containing all of the values that I wanted to exclude because, in my case, there could potentially be several hundred values to be excluded. If we were to apply the same refactoring to our simple sales region example we’d end up with: 1: DECLARE @regionsToIgnore TABLE (IgnoredRegionId INT) 2: INSERT @regionsToIgnore values (2),(4) 3:  4: SELECT 5: c.CustomerId, 6: c.CustomerName, 7: c.SalesRegionId 8: FROM Customers c 9: LEFT OUTER JOIN @regionsToIgnore r ON r.IgnoredRegionId = c.SalesRegionId 10: WHERE r.IgnoredRegionId IS NULL By performing a LEFT OUTER JOIN from Customers to the @regionsToIgnore table variable we can simply exclude any rows where the IgnoredRegionId is null, as those represent customers that DO NOT appear in the ignored regions list. This approach will likely perform better if the number of sales regions to ignore gets very large and it also will correctly include any customers that do not yet have a sales region.

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  • Application Composer Series: Where and When to use Groovy

    - by Richard Bingham
    This brief post is really intended as more of a reference than an article. The table below highlights two things, firstly where you can add you own custom logic via groovy code (end column), and secondly (middle column) when you might use each particular feature. Obviously this applies only where Application Composer exists, namely Fusion CRM and Oracle Sales Cloud, and is based on current (release 8) functionality. Feature Most Common Use Case Groovy Field Triggers React to run-time data changes. Only fired when the field is changed and upon submit. Y Object Triggers To extend the standard processing logic for an object, based on record creation, updates and deletes. There is a split between these firing events, with some related to UI/ADF actions and others originating in the database. UI Trigger Points: After Create - fires when a new object record is created. Commonly used to set default values for fields. Before Modify - Fires when the end-user tries to modify a field value. Could be used for generic warnings or extra security logic. Before Invalidate - Fires on the parent object when one of its child object records is created, updated, or deleted. For building in relationship logic. Before Remove - Fires when an attempt is made to delete an object record. Can be used to create conditions that prevent deletes. Database Trigger Points: Before Insert in Database - Fires before a new object is inserted into the database. Can be used to ensure a dependent record exists or check for duplicates. After Insert in Database - Fires after a new object is inserted into the database. Could be used to create a complementary record. Before Update in Database -Fires before an existing object is modified in the database. Could be used to check dependent record values. After Update in Database - Fires after an existing object is modified in the database. Could be used to update a complementary record. Before Delete in Database - Fires before an existing object is deleted from the database. Could be used to check dependent record values. After Delete in Database - Fires after an existing object is deleted from the database. Could be used to remove dependent records. After Commit in Database - Fires after the change pending for the current object (insert, update, delete) is made permanent in the current transaction. Could be used when committed data that has passed all validation is required. After Changes Posted to Database - Fires after all changes have been posted to the database, but before they are permanently committed. Could be used to make additional changes that will be saved as part of the current transaction. Y Field Validation Displays a user entered error message based groovy logic validating the field value. The message is shown only when the validation logic returns false, and the logic is triggered only when tabbing out of the field on the user interface. Y Object Validation Commonly used where validation is needed across multiple related fields on the object. Triggered on the submit UI action. Y Object Workflows All Object Workflows are fired upon either record creation or update, along with the option of adding a custom groovy firing condition. Y Field Updates - change another field when a specified one changes. Intended as an easy way to set different run-time values (e.g. pick values for LOV's) plus the value field permits groovy logic entry. Y E-Mail Notification - sends an email notification to specified users/roles. Templates support using run-time value tokens and rich text. N Task Creation - for adding standard tasks for use in the worklist functionality. N Outbound Message - will create and send an XML payload of the related object SDO to a specified endpoint. N Business Process Flow - intended for approval using the seeded process, however can also trigger custom BPMN flows. N Global Functions Utility functions that can be called from any groovy code in Application Composer (across applications). Y Object Functions Utility functions that are local to the parent object. Usually triggered from within 'Buttons and Actions' definitions in Application Composer, although can be called from other code for that object (e.g. from a trigger). Y Add Custom Fields When adding custom fields there are a few places you can include groovy logic. Y Default Value - to add logic within setting the default value when new records are entered. Y Conditionally Updateable - to add logic to set the field to read-only or not. Y Conditionally Required - to add logic to set the field to required or not. Y Formula Field - Used to provide a new aggregate field that is entirely based on groovy logic and other field values. Y Simplified UI Layouts - Advanced Expressions Used for creating dynamic layouts for simplified UI pages where fields and regions show/hide based on run-time context values and logic. Also includes support for the depends-on feature as a trigger. Y Related References This Blog: Application Composer Series Extending Sales Guide: Using Groovy Scripts Groovy Scripting Reference Guide

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  • Developing Schema Compare for Oracle (Part 4): Script Configuration

    - by Simon Cooper
    If you've had a chance to play around with the Schema Compare for Oracle beta, you may have come across this screen in the synchronization wizard: This screen is one of the few screens that, along with the project configuration form, doesn't come from SQL Compare. This screen was designed to solve a couple of issues that, although aren't specific to Oracle, are much more of a problem than on SQL Server: Datatype conversions and NOT NULL columns. 1. Datatype conversions SQL Server is generally quite forgiving when it comes to datatype conversions using ALTER TABLE. For example, you can convert from a VARCHAR to INT using ALTER TABLE as long as all the character values are parsable as integers. Oracle, on the other hand, only allows ALTER TABLE conversions that don't change the internal data format. Essentially, every change that requires an actual datatype conversion has to be done using a rebuild with a conversion function. That's OK, as we can simply hard-code the various conversion functions for the valid datatype conversions and insert those into the rebuild SELECT list. However, as there always is with Oracle, there's a catch. Have a look at the NUMTODSINTERVAL function. As well as specifying the value (or column) to convert, you have to specify an interval_unit, which tells oracle how to interpret the input number. We can't hardcode a default for this parameter, as it is entirely dependent on the user's data context! So, in order to convert NUMBER to INTERVAL DAY TO SECOND/INTERVAL YEAR TO MONTH, we need to have feedback from the user as to what to put in this parameter while we're generating the sync script - this requires a new step in the engine action/script generation to insert these values into the script, as well as new UI to allow the user to specify these values in a sensible fashion. In implementing the engine and UI infrastructure to allow this it made much more sense to implement it for any rebuild datatype conversion, not just NUMBER to INTERVALs. For conversions which we can do, we pre-fill the 'value' box with the appropriate function from the documentation. The user can also type in arbitary SQL expressions, which allows the user to specify optional format parameters for the relevant conversion functions, or indeed call their own functions to convert between values that don't have a built-in conversion defined. As the value gets inserted as-is into the rebuild SELECT list, any expression that is valid in that context can be specified as the conversion value. 2. NOT NULL columns Another problem that is solved by the new step in the sync wizard is adding a NOT NULL column to a table. If the table contains data (as most database tables do), you can't just add a NOT NULL column, as Oracle doesn't know what value to put in the new column for existing rows - the DDL statement will fail. There are actually 3 separate scenarios for this problem that have separate solutions within the engine: Adding a NOT NULL column to a table without a rebuild Here, the workaround is to add a column default with an appropriate value to the column you're adding: ALTER TABLE tbl1 ADD newcol NUMBER DEFAULT <value> NOT NULL; Note, however, there is something to bear in mind about this solution; once specified on a column, a default cannot be removed. To 'remove' a default from a column you change it to have a default of NULL, hence there's code in the engine to treat a NULL default the same as no default at all. Adding a NOT NULL column to a table, where a separate change forced a table rebuild Fortunately, in this case, a column default is not required - we can simply insert the default value into the rebuild SELECT clause. Changing an existing NULL to a NOT NULL column To implement this, we run an UPDATE command before the ALTER TABLE to change all the NULLs in the column to the required default value. For all three, we need some way of allowing the user to specify a default value to use instead of NULL; as this is essentially the same problem as datatype conversion (inserting values into the sync script), we can re-use the UI and engine implementation of datatype conversion values. We also provide the option to alter the new column to allow NULLs, or to ignore the problem completely. Note that there is the same (long-running) problem in SQL Compare, but it is much more of an issue in Oracle as you cannot easily roll back executed DDL statements if the script fails at some point during execution. Furthermore, the engine of SQL Compare is far less conducive to inserting user-supplied values into the generated script. As we're writing the Schema Compare engine from scratch, we used what we learnt from the SQL Compare engine and designed it to be far more modular, which makes inserting procedures like this much easier.

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  • LINQ and ArcObjects

    - by Marko Apfel
    Motivation LINQ (language integrated query) is a component of the Microsoft. NET Framework since version 3.5. It allows a SQL-like query to various data sources such as SQL, XML etc. Like SQL also LINQ to SQL provides a declarative notation of problem solving – i.e. you don’t need describe in detail how a task could be solved, you describe what to be solved at all. This frees the developer from error-prone iterator constructs. Ideally, of course, would be to access features with this way. Then this construct is conceivable: var largeFeatures = from feature in features where (feature.GetValue("SHAPE_Area").ToDouble() > 3000) select feature; or its equivalent as a lambda expression: var largeFeatures = features.Where(feature => (feature.GetValue("SHAPE_Area").ToDouble() > 3000)); This requires an appropriate provider, which manages the corresponding iterator logic. This is easier than you might think at first sight - you have to deliver only the desired entities as IEnumerable<IFeature>. LINQ automatically establishes a state machine in the background, whose execution is delayed (deferred execution) - when you are really request entities (foreach, Count (), ToList (), ..) an instantiation processing takes place, although it was already created at a completely different place. Especially in multiple iteration through entities in the first debuggings you are rubbing your eyes when the execution pointer jumps magically back in the iterator logic. Realization A very concise logic for constructing IEnumerable<IFeature> can be achieved by running through a IFeatureCursor. You return each feature via yield. For an easier usage I have put the logic in an extension method Getfeatures() for IFeatureClass: public static IEnumerable<IFeature> GetFeatures(this IFeatureClass featureClass, IQueryFilter queryFilter, RecyclingPolicy policy) { IFeatureCursor featureCursor = featureClass.Search(queryFilter, RecyclingPolicy.Recycle == policy); IFeature feature; while (null != (feature = featureCursor.NextFeature())) { yield return feature; } //this is skipped in unit tests with cursor-mock if (Marshal.IsComObject(featureCursor)) { Marshal.ReleaseComObject(featureCursor); } } So you can now easily generate the IEnumerable<IFeature>: IEnumerable<IFeature> features = _featureClass.GetFeatures(RecyclingPolicy.DoNotRecycle); You have to be careful with the recycling cursor. After a delayed execution in the same context it is not a good idea to re-iterated on the features. In this case only the content of the last (recycled) features is provided and all the features are the same in the second set. Therefore, this expression would be critical: largeFeatures.ToList(). ForEach(feature => Debug.WriteLine(feature.OID)); because ToList() iterates once through the list and so the the cursor was once moved through the features. So the extension method ForEach() always delivers the same feature. In such situations, you must not use a recycling cursor. Repeated executions of ForEach() is not a problem, because for every time the state machine is re-instantiated and thus the cursor runs again - that's the magic already mentioned above. Perspective Now you can also go one step further and realize your own implementation for the interface IEnumerable<IFeature>. This requires that only the method and property to access the enumerator have to be programmed. In the enumerator himself in the Reset() method you organize the re-executing of the search. This could be archived with an appropriate delegate in the constructor: new FeatureEnumerator<IFeatureclass>(_featureClass, featureClass => featureClass.Search(_filter, isRecyclingCursor)); which is called in Reset(): public void Reset() { _featureCursor = _resetCursor(_t); } In this manner, enumerators for completely different scenarios could be implemented, which are used on the client side completely identical like described above. Thus cursors, selection sets, etc. merge into a single matter and the reusability of code is increasing immensely. On top of that in automated unit tests an IEnumerable could be mocked very easily - a major step towards better software quality. Conclusion Nevertheless, caution should be exercised with these constructs in performance-relevant queries. Because of managing a state machine in the background, a lot of overhead is created. The processing costs additional time - about 20 to 100 percent. In addition, working without a recycling cursor is fast a performance gap. However declarative LINQ code is much more elegant, flawless and easy to maintain than manually iterating, compare and establish a list of results. The code size is reduced according to experience an average of 75 to 90 percent! So I like to wait a few milliseconds longer. As so often it has to be balanced between maintainability and performance - which for me is gaining in priority maintainability. In times of multi-core processors, the processing time of most business processes is anyway not dominated by code execution but by waiting for user input. Demo source code The source code for this prototype with several unit tests, you can download here: https://github.com/esride-apf/Linq2ArcObjects. .

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  • Coherence Data Guarantees for Data Reads - Basic Terminology

    - by jpurdy
    When integrating Coherence into applications, each application has its own set of requirements with respect to data integrity guarantees. Developers often describe these requirements using expressions like "avoiding dirty reads" or "making sure that updates are transactional", but we often find that even in a small group of people, there may be a wide range of opinions as to what these terms mean. This may simply be due to a lack of familiarity, but given that Coherence sits at an intersection of several (mostly) unrelated fields, it may be a matter of conflicting vocabularies (e.g. "consistency" is similar but different in transaction processing versus multi-threaded programming). Since almost all data read consistency issues are related to the concept of concurrency, it is helpful to start with a definition of that, or rather what it means for two operations to be concurrent. Rather than implying that they occur "at the same time", concurrency is a slightly weaker statement -- it simply means that it can't be proven that one event precedes (or follows) the other. As an example, in a Coherence application, if two client members mutate two different cache entries sitting on two different cache servers at roughly the same time, it is likely that one update will precede the other by a significant amount of time (say 0.1ms). However, since there is no guarantee that all four members have their clocks perfectly synchronized, and there is no way to precisely measure the time it takes to send a given message between any two members (that have differing clocks), we consider these to be concurrent operations since we can not (easily) prove otherwise. So this leads to a question that we hear quite frequently: "Are the contents of the near cache always synchronized with the underlying distributed cache?". It's easy to see that if an update on a cache server results in a message being sent to each near cache, and then that near cache being updated that there is a window where the contents are different. However, this is irrelevant, since even if the application reads directly from the distributed cache, another thread update the cache before the read is returned to the application. Even if no other member modifies a cache entry prior to the local near cache entry being updated (and subsequently read), the purpose of reading a cache entry is to do something with the result, usually either displaying for consumption by a human, or by updating the entry based on the current state of the entry. In the former case, it's clear that if the data is updated faster than a human can perceive, then there is no problem (and in many cases this can be relaxed even further). For the latter case, the application must assume that the value might potentially be updated before it has a chance to update it. This almost aways the case with read-only caches, and the solution is the traditional optimistic transaction pattern, which requires the application to explicitly state what assumptions it made about the old value of the cache entry. If the application doesn't want to bother stating those assumptions, it is free to lock the cache entry prior to reading it, ensuring that no other threads will mutate the entry, a pessimistic approach. The optimistic approach relies on what is sometimes called a "fuzzy read". In other words, the application assumes that the read should be correct, but it also acknowledges that it might not be. (I use the qualifier "sometimes" because in some writings, "fuzzy read" indicates the situation where the application actually sees an original value and then later sees an updated value within the same transaction -- however, both definitions are roughly equivalent from an application design perspective). If the read is not correct it is called a "stale read". Going back to the definition of concurrency, it may seem difficult to precisely define a stale read, but the practical way of detecting a stale read is that is will cause the encompassing transaction to roll back if it tries to update that value. The pessimistic approach relies on a "coherent read", a guarantee that the value returned is not only the same as the primary copy of that value, but also that it will remain that way. In most cases this can be used interchangeably with "repeatable read" (though that term has additional implications when used in the context of a database system). In none of cases above is it possible for the application to perform a "dirty read". A dirty read occurs when the application reads a piece of data that was never committed. In practice the only way this can occur is with multi-phase updates such as transactions, where a value may be temporarily update but then withdrawn when a transaction is rolled back. If another thread sees that value prior to the rollback, it is a dirty read. If an application uses optimistic transactions, dirty reads will merely result in a lack of forward progress (this is actually one of the main risks of dirty reads -- they can be chained and potentially cause cascading rollbacks). The concepts of dirty reads, fuzzy reads, stale reads and coherent reads are able to describe the vast majority of requirements that we see in the field. However, the important thing is to define the terms used to define requirements. A quick web search for each of the terms in this article will show multiple meanings, so I've selected what are generally the most common variations, but it never hurts to state each definition explicitly if they are critical to the success of a project (many applications have sufficiently loose requirements that precise terminology can be avoided).

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  • Deadlock Analysis in NetBeans 8

    - by Geertjan
    Lock contention profiling is very important in multi-core environments. Lock contention occurs when a thread tries to acquire a lock while another thread is holding it, forcing it to wait. Lock contentions result in deadlocks. Multi-core environments have even more threads to deal with, causing an increased likelihood of lock contentions. In NetBeans 8, the NetBeans Profiler has new support for displaying detailed information about lock contention, i.e., the relationship between the threads that are locked. After all, whenever there's a deadlock, in any aspect of interaction, e.g., a political deadlock, it helps to be able to point to the responsible party or, at least, the order in which events happened resulting in the deadlock. As an example, let's take the handy Deadlock sample code from the Java Tutorial and look at the tools in NetBeans IDE for identifying and analyzing the code. The description of the deadlock is nice: Alphonse and Gaston are friends, and great believers in courtesy. A strict rule of courtesy is that when you bow to a friend, you must remain bowed until your friend has a chance to return the bow. Unfortunately, this rule does not account for the possibility that two friends might bow to each other at the same time. To help identify who bowed first or, at least, the order in which bowing took place, right-click the file and choose "Profile File". In the Profile Task Manager, make the choices below: When you have clicked Run, the Threads window shows the two threads are blocked, i.e., the red "Monitor" lines tell you that the related threads are blocked while trying to enter a synchronized method or block: But which thread is holding the lock? Which one is blocked by the other? The above visualization does not answer these questions. New in NetBeans 8 is that you can analyze the deadlock in the new Lock Contention window to determine which of the threads is responsible for the lock: Here is the code that simulates the lock, very slightly tweaked at the end, where I use "setName" on the threads, so that it's even easier to analyze the threads in the relevant NetBeans tools. Also, I converted the anonymous inner Runnables to lambda expressions. package org.demo; public class Deadlock { static class Friend { private final String name; public Friend(String name) { this.name = name; } public String getName() { return this.name; } public synchronized void bow(Friend bower) { System.out.format("%s: %s" + " has bowed to me!%n", this.name, bower.getName()); bower.bowBack(this); } public synchronized void bowBack(Friend bower) { System.out.format("%s: %s" + " has bowed back to me!%n", this.name, bower.getName()); } } public static void main(String[] args) { final Friend alphonse = new Friend("Alphonse"); final Friend gaston = new Friend("Gaston"); Thread t1 = new Thread(() -> { alphonse.bow(gaston); }); t1.setName("Alphonse bows to Gaston"); t1.start(); Thread t2 = new Thread(() -> { gaston.bow(alphonse); }); t2.setName("Gaston bows to Alphonse"); t2.start(); } } In the above code, it's extremely likely that both threads will block when they attempt to invoke bowBack. Neither block will ever end, because each thread is waiting for the other to exit bow. Note: As you can see, it really helps to use "Thread.setName", everywhere, wherever you're creating a Thread in your code, since the tools in the IDE become a lot more meaningful when you've defined the name of the thread because otherwise the Profiler will be forced to use thread names like "thread-5" and "thread-6", i.e., based on the order of the threads, which is kind of meaningless. (Normally, except in a simple demo scenario like the above, you're not starting the threads in the same class, so you have no idea at all what "thread-5" and "thread-6" mean because you don't know the order in which the threads were started.) Slightly more compact: Thread t1 = new Thread(() -> { alphonse.bow(gaston); },"Alphonse bows to Gaston"); t1.start(); Thread t2 = new Thread(() -> { gaston.bow(alphonse); },"Gaston bows to Alphonse"); t2.start();

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