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• How to deal this situation

  - by user198725878

  I would like to ask you some guidance here. Once I finished my graduation I join a company for Ruby On Rails. They trained me and put into project for ROR. I have spent 1 year of ROR development. I have done basic things in the given project. Then my company got a project for QT, learned and worked for nearly 7 months. Then my company put into me in iOS development. For the past 1 1/2 years, I have been working in the iOS development till date. Also my main worry is, changing the technology I am working makes me not having in depth knowledge on anything. I mean I can't make myself as expert in any language. What is your opinion? Now my company is going to put me into the cross-platform mobile application development. I am worried now, will this affect my growth path by leaving native development? I am ready to learn Android. As I left web development before 2 year ago, I am finding some odds with me. Should look for iOS job change now? Please let me know your advices.

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• best way to send messages to all subscribers with multiple subscriptions and multiple providers

  - by coding_idiot

  I'm writing an application in which - Many users can subsribe to posts made by another users. So for a single publisher there can be many subscribers. When a message is posted by an user X, all users who have subscribed to messages of User X will be sent an email. How to achieve this ? I'm thinking of using publish-subscribe pattern. And then I came through JMS. Which is the best JMS implementation to use according to your experience ? Or else what else solution do you propose to the given problem ? Shall I go for a straight-forward solution ?: User x posts a message, I find all users (from database) who subscribe to user x and then for every user, I call the sendEmail() method. [EDIT] My intention here is not to send-emails. I'm really sorry if it wasn't clear. I also have to send kind of system-notifications apart from Email to all subscribers. Right now, I've implemented the email-sending as a threadPool

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• WCF REST Error Handler

  - by Elton Stoneman

  I’ve put up on GitHub a sample WCF error handler for REST services, which returns proper HTTP status codes in response to service errors.   The code is very simple – a ServiceBehavior implementation which can be specified in config to tag the RestErrorHandler to a service. Any uncaught exceptions will be routed to the error handler, which sets the HTTP status code and description in the response, based on the type of exception.   The sample defines a ClientException which can be thrown in code to indicate a problem with the client’s request, and the response will be a status 400 with a friendly error message:       throw new ClientException("Invalid userId. Must be provided as a positive integer");   - responds:   Request URL http://localhost/Sixeyed.WcfRestErrorHandler.Sample/ErrorProneService.svc/lastLogin?userId=xyz   Error Status Code: 400, Description: Invalid userId. Must be provided as a positive integer   Any other uncaught exceptions are hidden from the client. The full details are logged with a GUID to identify the error, and the response to the client is a status 500 with a generic message giving them the GUID to follow up on:       var iUserId = 0;     var dbz = 1 / iUserId;   - logs the divide-by-zero error and responds:   Request URL http://localhost/Sixeyed.WcfRestErrorHandler.Sample/ErrorProneService.svc/dbz     Error Status Code: 500, Description: Something has gone wrong. Please contact our support team with helpdesk ID: C9C5A968-4AEA-48C7-B90A-DEC986F80DA5   The sample demonstrates two techniques for building the response. For client exceptions, a friendly HTML response is sent in the body as well as the status code and description. Personally I prefer not to do that – it doesn’t make sense to get a 400 error and find text/html when you’re expecting application/json, but it’s easy to do if that’s the functionality you want. The other option is to send an empty response, which the sample does with server exceptions.   The obvious extension is to have multiple exceptions representing all the status codes you want to provide, then your code is as simple as throwing the relevant exception – UnauthorizedException, ForbiddenExeption, NotImplementedException etc – anywhere in the stack, and it will be handled nicely.

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• Is there any way to send a column value from outer query to inner sub query? [closed]

  - by chetan

  'Discussions' table schema title description desid replyto upvote downvote views browser used a1 none 1 1 12 - bad topic b2 a1 2 3 14 sql database a3 none 4 5 34 - crome b4 a3 3 4 12 The above table has two types of content types Main Topics and Comments. Unique content identifier 'desid' used to identify that its a main topic or a comment. 'desid' starts with 'a' for Main Topic and for comment 'desid' starts with 'b'. For comment 'replyto' is the 'desid' of main topic to which this comment is associated. I like to find out the list of the top main topics that are arranged on the basis of (upvote+downvote+visits+number of comments to it) addition. The following query gives top topics list in order of (upvote+downvote+visits) select * with highest number of upvote+downvote+views by query "select * from [DB_user1212].[dbo].[discussions] where desid like 'a%' order by (upvote+downvote+visited) desc For (comments+upvote+downvote+views ) I tried select * from [DB_user1212].[dbo].[discussions] where desid like 'a%' order by ((select count(*) from [DB_user1212].[dbo].[discussions] where replyto = desid )+upvote+downvote+visited) desc but it didn't work because its not possible to send desid from outer query to inner subquery. How to solve this? Please note that I want solution in query language only.

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• Why is CS never a topic of conversation of the layman? [closed]

  - by hydroparadise

  Granted, every profession has it's technicalities. If you are an MD, you better know the anatomy of the human body, and if you are astronomer, you better know your calculus. Yet, you don't have to know these more advance topics to know that smoking might give you lung cancer because of carcinogens or the moon revolves around the earth because of gravity (thank you Discovery Channel). There's sort of a common knowledge (at least in more developed countries) of these more advanced topics. With that said, why are things like recursive descent parsing, BNF, or Turing machines hardly ever mentioned outsided 3000 or 4000 level classes in a university setting or between colleagues? Even back in my days before college in my pursuit of knowledge on how computers work, these very important topics (IMHO) never seem to get the light of day. Many different sources and sites go into "What is a processor?" or "What is RAM?", or "What is an OS?". You might get lucky and discover something about programming languages and how they play a role in how applications are created, but nothing about the tools for creating the language itself. To extend this idea, Dennis Ritchie died shortly after Steve Jobs, yet Dennis Ritchie got very little press compared to Steve Jobs. So, the heart of my question: Does the public in general not care to hear about computer science topics that make the technology in their lives work, or does the computer science community not lend itself to the general public to close the knowledge gap? Am I wrong to think the general public has the same thirst for knowledge on how things work as I do? Please consider the question carefully before answering or vote closing please.

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• Is error suppression acceptable in role of logic mechanism?

  - by Rarst

  This came up in code review at work in context of PHP and @ operator. However I want to try keep this in more generic form, since few question about it I found on SO got bogged down in technical specifics. Accessing array field, which is not set, results in error message and is commonly handled by following logic (pseudo code): if field value is set output field value Code in question was doing it like: start ignoring errors output field value stop ignoring errors The reasoning for latter was that it's more compact and readable code in this specific case. I feel that those benefits do not justify misuse (IMO) of language mechanics. Is such code is being "clever" in a bad way? Is discarding possible error (for any reason) acceptable practice over explicitly handling it (even if that leads to more extensive and/or intensive code)? Is it acceptable for programming operators to cross boundaries of intended use (like in this case using error handling for controlling output)? Edit I wanted to keep it more generic, but specific code being discussed was like this: if ( isset($array['field']) ) { echo '<li>' . $array['field'] . '</li>'; } vs the following example: echo '<li>' . @$array['field'] . '</li>';

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• I have an MIS degree. How do I sell myself as a programmer?

  - by hydroparadise

  So, I graduated with a BSBA in Management Information Systems with honors almost 2 years ago which is more of a business degree. As of right now, I do have a job title of "Programmer", but it's more of a report writing position in an arbitrary, proprietary language called PowerOn with the occasional interesting project using more mainstream technologies like .Net and Java. I am also somewhat isoloated being the only programmer in the workplace, which I beleive is a detriment to my career path. The only people I have to bounce ideas against are those on the various SE sites. I don't regret going MIS, but over the past couple of years I have discovered my passion for coding, even though I have been doing some form of coding profesionally and as an enthusiast for years. I do want to persue my Masters in CS (at a later time), but I am not sure if I necessarily need a CS degree to get in with a team of programmers. In addition, I do have a number classes I have taken for different laguanges on the way (C++, Java, SQL, and VB.Net) I beleive my strength is in problem solving where code is just a tool to tackling to problem if needed. My question: How do I best sell myself as a programmer? Should I continue pounding out reports and wait till I have my masters in CS? Or am I viable to be a programmer as I stand?

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• Unit testing to prove balanced tree

  - by Darrel Hoffman

  I've just built a self-balancing tree (red-black) in Java (language should be irrelevant for this question though), and I'm trying to come up with a good means of testing that it's properly balanced. I've tested all the basic tree operations, but I can't think of a way to test that it is indeed well and truly balanced. I've tried inserting a large dictionary of words, both pre-sorted and un-sorted. With a balanced tree, those should take roughly the same amount of time, but an unbalanced tree would take significantly longer on the already-sorted list. But I don't know how to go about testing for that in any reasonable, reproducible way. (I've tried doing millisecond tests on these, but there's no noticeable difference - probably because my source data is too small.) Is there a better way to be sure that the tree is really balanced? Say, by looking at the tree after it's created and seeing how deep it goes? (That is, without modifying the tree itself by adding a depth field to each node, which is just wasteful if you don't need it for anything other than testing.)

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• Assignments in mock return values

  - by zerkms

  (I will show examples using php and phpunit but this may be applied to any programming language) The case: let's say we have a method A::foo that delegates some work to class M and returns the value as-is. Which of these solutions would you choose: $mock = $this->getMock('M'); $mock->expects($this->once()) ->method('bar') ->will($this->returnValue('baz')); $obj = new A($mock); $this->assertEquals('baz', $obj->foo()); or $mock = $this->getMock('M'); $mock->expects($this->once()) ->method('bar') ->will($this->returnValue($result = 'baz')); $obj = new A($mock); $this->assertEquals($result, $obj->foo()); or $result = 'baz'; $mock = $this->getMock('M'); $mock->expects($this->once()) ->method('bar') ->will($this->returnValue($result)); $obj = new A($mock); $this->assertEquals($result, $obj->foo()); Personally I always follow the 2nd solution, but just 10 minutes ago I had a conversation with couple of developers who said that it is "too tricky" and chose 3rd or 1st. So what would you usually do? And do you have any conventions to follow in such cases?

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• Floating point undesirable in highly critical code?

  - by Kirt Undercoffer

  Question 11 in the Software Quality section of "IEEE Computer Society Real-World Software Engineering Problems", Naveda, Seidman, lists fp computation as undesirable because "the accuracy of the computations cannot be guaranteed". This is in the context of computing acceleration for an emergency braking system for a high speed train. This thinking seems to be invoking possible errors in small differences between measurements of a moving object but small differences at slow speeds aren't a problem (or shouldn't be), small differences between two measurements at high speed are irrelevant - can there be a problem with small roundoff errors during deceleration for an emergency braking system? This problem has been observed with airplane braking systems resulting in hydroplaning but could this actually happen in the context of a high speed train? The concern about fp errors seems to not be well-founded in this context. Any insight? The fp is used for acceleration so perhaps the concern is inching over a speed limit? But fp should be just fine if they use a double in whatever implementation language. The actual problem in the text states: During the inspection of the code for the emergency braking system of a new high speed train (a highly critical, real-time application), the review team identifies several characteristics of the code. Which of these characteristics are generally viewed as undesirable? The code contains three recursive functions (well that one is obvious). The computation of acceleration uses floating point arithmetic. All other computations use integer arithmetic. The code contains one linked list that uses dynamic memory allocation (second obvious problem). All inputs are checked to determine that they are within expected bounds before they are used.

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• BPI On Demand achieves both Oracle Fusion CRM Cloud Service 2013 Specialisation and Reseller status!

  - by Richard Lefebvre

  Oracle is delighted to share with you that BPI OnDemand has achieved the Oracle Fusion CRM Cloud Service 2013 Specialization and is the EMEA first ever Oracle Sales Cloud reseller ! One of Oracle's most active CRM SaaS partners across EMEA, BPI OnDemand operates out of the UK with subsidiaries in Spain and South Africa that will also benefit locally from the specialization and reseller status. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* 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-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} BPI OnDemand distinguishes itself from other Oracle Sales Cloud integrators with 2 unique implementation options: 1) Rapid Advantage Fixed Scope for as low as £20,000 or their famous 2) Zero upfront cost Fully Managed Cloud CRM Service which has no equivalent in Europe. BPI OnDemand has already 2 Oracle Sales Cloud live customers and is engaging in many other opportunities including large corporate accounts. Meet BPI OnDemand here or on LinkedIn or on Twitter

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• How do I draw a dotted or dashed line?

  - by Gagege

  I'm trying to draw a dashed or dotted line by placing individual segments(dashes) along a path and then separating them. The only algorithm I could come up with for this gave me a dash length that was variable based on the angle of the line. Like this: private function createDashedLine(fromX:Float, fromY:Float, toX:Float, toY:Float):Sprite { var line = new Sprite(); var currentX = fromX; var currentY = fromY; var addX = (toX - fromX) * 0.0075; var addY = (toY - fromY) * 0.0075; line.graphics.lineStyle(1, 0xFFFFFF); var count = 0; // while line is not complete while (!lineAtDestination(fromX, fromY, toX, toY, currentX, currentY)) { /// move line draw cursor to beginning of next dash line.graphics.moveTo(currentX, currentY); // if dash is even if (count % 2 == 0) { // draw the dash line.graphics.lineTo(currentX + addX, currentY + addY); } // add next dash's length to current cursor position currentX += addX; currentY += addY; count++; } return line; } This just happens to be written in Haxe, but the solution should be language neutral. What I would like is for the dash length to be the same no matter what angle the line is. As is, it's just adding 75 thousandths of the line length to the x and y, so if the line is and a 45 degree angle you get pretty much a solid line. If the line is at something shallow like 85 degrees then you get a nice looking dashed line. So, the dash length is variable, and I don't want that. How would I make a function that I can pass a "dash length" into and get that length of dash, no matter what the angle is? If you need to completely disregard my code, be my guest. I'm sure there's a better solution.

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• How to handle sorting of complex objects?

  - by AedonEtLIRA

  How would one sort a list of objects that have more than one sortable element? Suppose you have a simple object Car and car is a defined as such: class Car { public String make; public String model; public int year; public String color; // ... No methods, just a structure / container } I designed a simple framework that would allow for multiple SortOptions to be provided to a Sorter that would then sort the list. interface ISorter<T> { List<T> sort(List<T> items); void addSortOption(ISortOption<T> option); ISortOption<T>[] getSortOptions(); void setSortOption(ISortOption<T> option); } interface ISortOption<T> { String getLabel(); int compare(T t1, T t2); } Example use class SimpleStringSorter extends MergeSorter<String> { { addSorter(new AlphaSorter()); } private static final class AlphaSorter implements ISortOption<String> { // ... implementation of alpha compare and get label } } The issue with this solution is that it is not easily expandable. If car was to ever receive a new field, say, currentOwner. I would need to add the field, then track down the sorter class file, implement a new sort option class then recompile the application for redistribution. Is there an easier more expandable/practical way to sort data like this?

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• Costs/profit of/when starting an indie company

  - by Jack

  In short, I want to start a game company. I do not have much coding experience (just basic understanding and ability to write basic programs), any graphics design experience, any audio mixing experience, or whatever else technical. However, I do have a lot of ideas, great analytical skills and a very logical approach to life. I do not have any friends who are even remotely technical (or creative in regards to games for that matter). So now that we've cleared that up, my question is this: how much, minimally, would it cost me to start such a company? I know that a game could be developed in under half a year, which means it would have to operate for half a year prior, and that's assuming that the people working on the first project do their jobs good, don't leave game breaking bugs, a bunch of minor bugs, etc.. So how much would it cost me, and what would be the likely profit in half a year? I'm looking at minimal costs here, as to do it, I would have to sell my current apartment and buy a new, smaller one, pay taxes, and likely move to US/CA/UK to be closer to technologically advanced people (and be able to speak the language of course). EDIT: I'm looking at a small project for starters, not a huge AAA title.

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• How do I drag my widgets without dragging other widgets?

  - by Cypher

  I have a bunch of drag-able widgets on screen. When I am dragging one of the widgets around, if I drag the mouse over another widget, that widget then gets "snagged" and is also dragged around. While this is kind of a neat thing and I can think of a few game ideas based on that alone, that was not intended. :-P Background Info I have a Widget class that is the basis for my user interface controls. It has a bunch of properties that define it's size, position, image information, etc. It also defines some events, OnMouseOver, OnMouseOut, OnMouseClick, etc. All of the event handler functions are virtual, so that child objects can override them and make use of their implementation without duplicating code. Widgets are not aware of each other. They cannot tell each other, "Hey, I'm dragging so bugger off!" Source Code Here's where the widget gets updated (every frame): public virtual void Update( MouseComponent mouse, KeyboardComponent keyboard ) { // update position if the widget is being dragged if ( this.IsDragging ) { this.Left -= (int)( mouse.LastPosition.X - mouse.Position.X ); this.Top -= (int)( mouse.LastPosition.Y - mouse.Position.Y ); } ... // define and throw other events if ( !this.WasMouseOver && this.IsMouseOver && mouse.IsButtonDown( MouseButton.Left ) ) { this.IsMouseDown = true; this.MouseDown( mouse, new EventArgs() ); } ... // define and throw other events } And here's the OnMouseDown event where the IsDraggable property gets set: public virtual void OnMouseDown( object sender, EventArgs args ) { if ( this.IsDraggable ) { this.IsDragging = true; } } Problem Looking at the source code, it's obvious why this is happening. The OnMouseDown event gets fired whenever the mouse is hovered over the Widget and when the left mouse button is "down" (but not necessarily in that order!). That means that even if I hold the mouse down somewhere else on screen, and simply move it over anything that IsDraggable, it will "hook" onto the mouse and go for a ride. So, now that it's obvious that I'm Doing It Wrong™, how do I do this correctly?

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• Moving away from PHP and running towards server-side JavaScript [on hold]

  - by Sosukodo

  I've decided to start moving away from PHP and server-side JavaScript looks like an attractive replacement. However, I'm having a hard time wrapping my head around how others are using Node.js for web applications. I'm currently using Lighttpd with FastCGI PHP. The one thing I like about PHP is that I can "inline" my scripts in the document like so: <?php echo 'Hello, World!'; ?> My question is: Is there any server-side JavaScript solution that I can use in this manor? For instance, I'd love to be able to do this: <?js print('Hello, World!'); ?> Is there such a thing? I'm not looking for opinions about "which is better". I just want to know what's out there and I'll explore each of them on my own. The important thing is that I'd like to use it like I demonstrated above. Links to the software along with implementation examples will be considered above other answers.

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• Which things instantly ring alarm bells when looking at code? [closed]

  - by FinnNk

  I attended a software craftsmanship event a couple of weeks ago and one of the comments made was "I'm sure we all recognize bad code when we see it" and everyone nodded sagely without further discussion. This sort of thing always worries me as there's that truism that everyone thinks they're an above average driver. Although I think I can recognize bad code I'd love to learn more about what other people consider to be code smells as it's rarely discussed in detail on people's blogs and only in a handful of books. In particular I think it'd be interesting to hear about anything that's a code smell in one language but not another. I'll start off with an easy one: Code in source control that has a high proportion of commented out code - why is it there? was it meant to be deleted? is it a half finished piece of work? maybe it shouldn't have been commented out and was only done when someone was testing something out? Personally I find this sort of thing really annoying even if it's just the odd line here and there, but when you see large blocks interspersed with the rest of the code it's totally unacceptable. It's also usually an indication that the rest of the code is likely to be of dubious quality as well.

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• How will closures in Java impact the Java Community?

  - by Ryan Delucchi

  It is one of the most talked about features planned for Java: Closures. Many of us have been longing for them. Some of us (including I) have grown a bit impatient and have turned to scripting languages to fill the void. But, once closures have finally arrived to Java: how will they effect the Java Community? Will the advancement of VM-targetted scripting languages slow to a crawl, stay the same, or acclerate? Will people flock to the new closure syntax, thus turning Java code-bases all-around into more functionally structured implementations? Will we only see closures sprinkled in Java throughout? What will be the effect on tool/IDE support? How about performance? And finally, what will it mean for Java's continued adoption, as a language, compared with other languages that are rising in popularity? To provide an example of one of the latest proposed Java Closure syntax specs: public interface StringOperation { String invoke(String s); } // ... (new StringOperation() { public invoke(String s) { new StringBuilder(s).reverse().toString(); } }).invoke("abcd"); would become ... String reversed = { String s => new StringBuilder(s).reverse().toString() }.invoke("abcd"); [source: http://tronicek.blogspot.com/2007/12/closures-closure-is-form-of-anonymous_28.html]

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• TXPAUSE : polite waiting for hardware transactional memory

  - by Dave

  Classic locks are an appropriate tool to prevent potentially conflicting operations A and B, invoked by different threads, from running at the same time. In a sense the locks cause either A to run before B or vice-versa. Similarly, we can replace the locks with hardware transactional memory, or use transactional lock elision to leverage potential disjoint access parallelism between A and B. But often we want A to wait until B has run. In a Pthreads environment we'd usually use locks in conjunction with condition variables to implement our "wait until" constraint. MONITOR-MWAIT is another way to wait for a memory location to change, but it only allows us to track one cache line and it's only available on x86. There's no similar "wait until" construct for hardware transactions. At the instruction-set level a simple way to express "wait until" in transactions would be to add a new TXPAUSE instruction that could be used within an active hardware transaction. TXPAUSE would politely stall the invoking thread, possibly surrendering or yielding compute resources, while at the same time continuing to track the transaction's address-set. Once a transaction has executed TXPAUSE it can only abort. Ideally that'd happen when some other thread modifies a variable that's in the transaction's read-set or write-set. And since we're aborting all writes would be discarded. In a sense this gives us multi-location MWAIT but with much more flexibility. We could also augment the TXPAUSE with a cycle-count bound to cap the time spent stalled. I should note that we can already enter a tight spin loop in a transaction to wait for updates to address-set to cause an abort. Assuming that the implementation monitors the address-set via cache-coherence probes, by waiting in this fashion we actually communicate via the probes, and not via memory values. That is the updating thread signals the waiter via probes instead of by traditional memory values. But TXPAUSE gives us a polite way to spin.

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• OpenJDK In The News: AMD and Oracle to Collaborate in the OpenJDK Community [..]

  - by $utils.escapeXML($entry.author)

  During the JavaOne™ 2012 Strategy Keynote, AMD (NYSE: AMD) announced its participation in OpenJDK™ Project “Sumatra” in collaboration with Oracle and other members of the OpenJDK community to help bring heterogeneous computing capabilities to Java™ for server and cloud environments. The OpenJDK Project “Sumatra” will explore how the Java Virtual Machine (JVM), as well as the Java language and APIs, might be enhanced to allow applications to take advantage of graphics processing unit (GPU) acceleration, either in discrete graphics cards or in high-performance graphics processor cores such as those found in AMD accelerated processing units (APUs).“Affirming our plans to contribute to the OpenJDK Project represents the next step towards bringing heterogeneous computing to millions of Java developers and can potentially lead to future developments of new hardware models, as well as server and cloud programming paradigms,” said Manju Hegde, corporate vice president, Heterogeneous Applications and Developer Solutions at AMD. “AMD has an established track record of collaboration with open-software development communities from OpenCL™ to the Heterogeneous System Architecture (HSA) Foundation, and with this initiative we will help further the development of graphics acceleration within the Java community.”“We expect our work with AMD and other OpenJDK participants in Project “Sumatra” will eventually help provide Java developers with the ability to quickly leverage GPU acceleration for better performance,” said Georges Saab, vice president, Software Development, Java Platform Group at Oracle. "We hope individuals and other organizations interested in this exciting development will follow AMD's lead by joining us in Project “Sumatra."Quotes taken from the first press release from AMD mentioning OpenJDK, titled "AMD and Oracle to Collaborate in the OpenJDK Community to Explore Heterogeneous Computing for Java ".

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• Dealing with Fine-Grained Cache Entries in Coherence

  - by jpurdy

  On occasion we have seen significant memory overhead when using very small cache entries. Consider the case where there is a small key (say a synthetic key stored in a long) and a small value (perhaps a number or short string). With most backing maps, each cache entry will require an instance of Map.Entry, and in the case of a LocalCache backing map (used for expiry and eviction), there is additional metadata stored (such as last access time). Given the size of this data (usually a few dozen bytes) and the granularity of Java memory allocation (often a minimum of 32 bytes per object, depending on the specific JVM implementation), it is easily possible to end up with the case where the cache entry appears to be a couple dozen bytes but ends up occupying several hundred bytes of actual heap, resulting in anywhere from a 5x to 10x increase in stated memory requirements. In most cases, this increase applies to only a few small NamedCaches, and is inconsequential -- but in some cases it might apply to one or more very large NamedCaches, in which case it may dominate memory sizing calculations. Ultimately, the requirement is to avoid the per-entry overhead, which can be done either at the application level by grouping multiple logical entries into single cache entries, or at the backing map level, again by combining multiple entries into a smaller number of larger heap objects. At the application level, it may be possible to combine objects based on parent-child or sibling relationships (basically the same requirements that would apply to using partition affinity). If there is no natural relationship, it may still be possible to combine objects, effectively using a Coherence NamedCache as a "map of maps". This forces the application to first find a collection of objects (by performing a partial hash) and then to look within that collection for the desired object. This is most naturally implemented as a collection of entry processors to avoid pulling unnecessary data back to the client (and also to encapsulate that logic within a service layer). At the backing map level, the NIO storage option keeps keys on heap, and so has limited benefit for this situation. The Elastic Data features of Coherence naturally combine entries into larger heap objects, with the caveat that only data -- and not indexes -- can be stored in Elastic Data.

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• Gathering IP address and workstation information; does it belong in a state class?

  - by p.campbell

  I'm writing an enterprisey utility that collects exception information and writes to the Windows Event Log, sends an email, etc. This utility class will be used by all applications in the corporation: web, BizTalk, Windows Services, etc. Currently this class: holds state given to it via public properties calls out to .NET Framework methods to gather information about runtime details. Included are call to various properties and methods from System.Environment, Reflection details, etc. This implementation has the benefit of allowing all those callers not to have to make these same calls themselves. This means less code for the caller to forget, screw up, etc. Should this state class (please what's the phrase I'm looking for [like DTO]?) know how to resolve/determine runtime details (like the IP address and machine name that it's running on)? It seems to me on second thought that it's meant to be a class that should hold state, and not know how to call out to the .NET Framework to find information. var myEx = new AppProblem{MachineName="Riker"}; //Will get "Riker 10.0.0.1" from property MachineLongDesc Console.WriteLine("full machine details: " + myEx.MachineLongDesc); public class AppProblem { public string MachineName{get;set;} public string MachineLongDesc{ get{ if(string.IsNullOrEmpty(this.MachineName) { this.MachineName = Environment.MachineName; } return this.MachineName + " " + GetCurrentIP(); } } private string GetCurrentIP() { return System.Net.Dns.GetHostEntry(this.MachineName) .AddressList.First().ToString(); } } This code was written by hand from memory, and presented for simplicity, trying to illustrate the concept.

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• Should I avoid or embrace asking questions of other developers on the job?

  - by T.K.

  As a CS undergraduate, the people around me are either learning or are paid to teach me, but as a software developer, the people around me have tasks of their own. They aren't paid to teach me, and conversely, I am paid to contribute. When I first started working as a software developer co-op, I was introduced to a huge code base written in a language I had never used before. I had plenty of questions, but didn't want to bother my co-workers with all of them - it wasted their time and hurt my pride. Instead, I spent a lot of time bouncing between IDE and browser, trying to make sense of what had already been written and differentiate between expected behavior and symptoms of bugs. I'd ask my co-workers when I felt that the root of my lack of understanding was an in-house concept that I wouldn't find on the internet, but aside from that, I tried to confine my questions to lunch hours. Naturally, there were occasions where I wasted time trying to understand something in code on the internet that had, at its heart, an in-house concept, but overall, I felt I was productive enough during my first semester, contributing about as much as one could expect and gaining a pretty decent understanding of large parts of the product. I was wondering what senior developers felt about that mindset. Should new developers ask more questions to get to speed faster, or should they do their own research for themselves? I see benefits to both mindsets, and anticipate a large variety of responses, but I figure new developers might appreciate your answers without thinking to ask this question.

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• The idea of functionN in Scala / Functionaljava

  - by Luke Murphy

  From brain driven development It turns out, that every Function you’ll ever define in Scala, will become an instance of an Implementation which will feature a certain Function Trait. There is a whole bunch of that Function Traits, ranging from Function1 up to Function22. Since Functions are Objects in Scala and Scala is a statically typed language, it has to provide an appropriate type for every Function which comes with a different number of arguments. If you define a Function with two arguments, the compiler picks Function2 as the underlying type. Also, from Michael Froh's blog You need to make FunctionN classes for each number of parameters that you want? Yes, but you define the classes once and then you use them forever, or ideally they're already defined in a library (e.g. Functional Java defines classes F, F2, ..., F8, and the Scala standard library defines classes Function1, ..., Function22) So we have a list of function traits (Scala), and a list of interfaces (Functional-java) to enable us to have first class funtions. I am trying to understand exactly why this is the case. I know, in Java for example, when I write a method say, public int add(int a, int b){ return a + b; } That I cannot go ahead and write add(3,4,5); ( error would be something like : method add cannot be applied to give types ) We simply have to define an interface/trait for functions with different parameters, because of static typing?

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• Inactive JSRs looking for Spec Leads

  - by heathervc

  You may have noticed that some JSRs have a classification of "Inactive" on their JSR page.  The introduction of this term in 2009 was part of an effort to enable and encourage more transparency into the development of JSRs.  You can read more about Inactive JSRs here and also in the JCP FAQ.The following JSR proposals have been Inactive since at least 2009. If you are a JCP Member and are interested in taking over the Specification Lead role for one of these JSRs, please contact the PMO at [email protected] on or before 23 April 2012. With that message, please include the following: the subject line "Spec Lead for JSR ###," where '###' is the JSR number which JCP Member you represent why you wish to take over the Specification lead role Here is the current list of Inactive JSRs for which Members can request to become Specification Leads: JSR 122, JAIN JCAT JSR 161, JAIN ENUM API Specification JSR 182, JPay - Payment API for the Java Platform JSR 210, OSS Service Quality Management API JSR 241, The Groovy Programming Language JSR 251, Pricing API JSR 278, Resource Management API for Java ME JSR 304, Mobile Telephony API v2 JSR 305, Annotations for Software Defect Detection JSR 320, Services Framework

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