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• In Java it seems Public constructors are always a bad coding practice

  - by Adam Gent

  This maybe a controversial question and may not be suited for this forum (so I will not be insulted if you choose to close this question). It seems given the current capabilities of Java there is no reason to make constructors public ... ever. Friendly, private, protected are OK but public no. It seems that its almost always a better idea to provide a public static method for creating objects. Every Java Bean serialization technology (JAXB, Jackson, Spring etc...) can call a protected or private no-arg constructor. My questions are: I have never seen this practice decreed or written down anywhere? Maybe Bloch mentions it but I don't own is book. Is there a use case other than perhaps not being super DRY that I missed? EDIT: I explain why static methods are better. .1. For one you get better type inference. For example See Guava's http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained .2. As a designer of the class you can later change what is returned with a static method. .3. Dealing with constructor inheritance is painful especially if you have to pre-calculate something.

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• Java Concurrency in practice sample question

  - by andy boot

  I am reading "Java Concurrency in practice" and looking at the example code on page 51. According to the book this piece of code is at risk of of failure if it has not been published properly. Because I like to code examples and break them to prove how they work. I have tried to make it throw an AssertionError but have failed. (Leading me to my previous question) Can anyone post sample code so that an AssertionError is thrown? Rule: Do not modify the Holder class. public class Holder{ private int n; public Holder(int n){ this.n = n; } public void assertSanity(){ if (n != n) { throw new AssertionError("This statement is false"); } } } I have modified the class to make it more fragile but I still can not get an AssertionError thrown. class Holder2{ private int n; private int n2; public Holder2(int n) throws InterruptedException{ this.n = n; Thread.sleep(200); this.n2 = n; } public void assertSanity(){ if (n != n2) { throw new AssertionError("This statement is false"); } } } Is it possible to make either of the above classes throw an AssertionError? Or do we have to accept that they may occasionally do so and we can't write code to prove it?

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• Python Error-Checking Standard Practice

  - by chaindriver

  Hi, I have a question regarding error checking in Python. Let's say I have a function that takes a file path as an input: def myFunction(filepath): infile = open(filepath) #etc etc... One possible precondition would be that the file should exist. There are a few possible ways to check for this precondition, and I'm just wondering what's the best way to do it. i) Check with an if-statement: if not os.path.exists(filepath): raise IOException('File does not exist: %s' % filepath) This is the way that I would usually do it, though the same IOException would be raised by Python if the file does not exist, even if I don't raise it. ii) Use assert to check for the precondition: assert os.path.exists(filepath), 'File does not exist: %s' % filepath Using asserts seems to be the "standard" way of checking for pre/postconditions, so I am tempted to use these. However, it is possible that these asserts are turned off when the -o flag is used during execution, which means that this check might potentially be turned off and that seems risky. iii) Don't handle the precondition at all This is because if filepath does not exist, there will be an exception generated anyway and the exception message is detailed enough for user to know that the file does not exist I'm just wondering which of the above is the standard practice that I should use for my codes.

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• Is Assert.Fail() considered bad practice?

  - by Mendelt

  I use Assert.Fail a lot when doing TDD. I'm usually working on one test at a time but when I get ideas for things I want to implement later I quickly write an empty test where the name of the test method indicates what I want to implement as sort of a todo-list. To make sure I don't forget I put an Assert.Fail() in the body. When trying out xUnit.Net I found they hadn't implemented Assert.Fail. Of course you can always Assert.IsTrue(false) but this doesn't communicate my intention as well. I got the impression Assert.Fail wasn't implemented on purpose. Is this considered bad practice? If so why? @Martin Meredith That's not exactly what I do. I do write a test first and then implement code to make it work. Usually I think of several tests at once. Or I think about a test to write when I'm working on something else. That's when I write an empty failing test to remember. By the time I get to writing the test I neatly work test-first. @Jimmeh That looks like a good idea. Ignored tests don't fail but they still show up in a separate list. Have to try that out. @Matt Howells Great Idea. NotImplementedException communicates intention better than assert.Fail() in this case @Mitch Wheat That's what I was looking for. It seems it was left out to prevent it being abused in another way I abuse it.

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• Best Practice for Summary Footer (and the like) in MVC

  - by benpage

  Simple question on best practice. Say I have: public class Product { public string Name { get; set; } public string Price { get; set; } public int CategoryID { get; set; } public bool IsAvailable { get; set; } } and i have a view using IEnumerable< Product as the model, and i iterate through the Products on the page and want to show the total of the prices at the end of the list, should I use: <%= Model.Sum(x=> x.Price) %> or should I use some other method? This may extend to include more involved things like: <%= Model.Where(x=> x.CategoryID == 5 && x.IsAvailable).Sum(x=> x.Price) %> and even <% foreach (Product p in Model.Where(x=> x.IsAvailable) {%> -- insert html -- <% } %> <% foreach (Product p in Model.Where(x=> !x.IsAvailable) {%> -- insert html -- <% } %> I guess this comes down to should I have that sort of code within my view, or should i be passing it to my view in ViewData? Or perhaps some other way?

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• Best practice how to store HTML in a database column

  - by tbrandao

  I have an application that modifies a table dynamically, think spreadsheet), then upon saving the form (which the table is part of) ,I store that changed table (with user modifications) in a database column named html_Spreadhseet,along with the rest of the form data. right now I'm just storing the html in a plain text format with basic escaping of characters... I'm aware that this could be stored as a separate file, the source table (html_workseeet) already is. But from a data handling perspective its easier to save the changed html table to and from a column so as to avoid having to come up with a file management strategy (which folder will this live in, now must include folder in backups, security issues now need to apply to files, how to sync db security with file system etc.), so to minimize these issues I'm only storing the ... part in the database column. My question is should I gzip the HTML , maybe use JSON, or some other format to easily store and retrieve the HTML from the database column, what is the best practice to store HTML content in a datbase? Or just store it as I currently am as an escaped text column?

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• Internal Java code best practice for dealing with invalid REST API parameters

  - by user326389

  My colleague wrote the following stackoverflow question: other stack overflow question on this topic The question seems to have been misinterpreted and I want to find out the answer, so I'm starting this new question... hopefully a little more clear. Basically, we have a REST API. Users of our API call our methods with parameters. But sometimes users call them with the wrong parameters!! Maybe a mistake in their code, maybe they're just trying to play with us, maybe they're trying to see how we respond, who knows! We respond with HTTP status error codes and maybe a detailed description of the invalid parameter in the XML response. All is well. But internally we deal with these invalid parameters by throwing exceptions. For example, if someone looks up a Person object by giving us their profile id, but the profile id doesn't exist... we throw a PersonInvalidException when looking them up. Then we catch this exception in our API controller and send back an HTTP 400 status error code. Our question is... is this the best practice, throwing exceptions internally for this kind of user error? These exceptions never get propogated back to the user, this is a REST API. They only make our code cleaner. Otherwise we could have a validation method in each of our API controllers to make sure the parameters all make sense, but that seems inefficient. We have to look up things in our database potentially twice. Or we could return nulls and check for them, but that sucks... What are your thoughts?

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• Best practice for debug Asserts during Unit testing

  - by Steve Steiner

  Does heavy use of unit tests discourage the use of debug asserts? It seems like a debug assert firing in the code under test implies the unit test shouldn't exist or the debug assert shouldn't exist. "There can be only one" seems like a reasonable principle. Is this the common practice? Or do you disable your debug asserts when unit testing, so they can be around for integration testing? Edit: I updated 'Assert' to debug assert to distinguish an assert in the code under test from the lines in the unit test that check state after the test has run. Also here is an example that I believe shows the dilema: A unit test passes invalid inputs for a protected function that asserts it's inputs are valid. Should the unit test not exist? It's not a public function. Perhaps checking the inputs would kill perf? Or should the assert not exist? The function is protected not private so it should be checking it's inputs for safety.

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• Programming logic best practice - redundant checks

  - by eldblz

  I'm creating a large PHP project and I've a trivial doubt about how to proceed. Assume we got a class books, in this class I've the method ReturnInfo: function ReturnInfo($id) { if( is_numeric($id) ) { $query = "SELECT * FROM books WHERE id='" . $id . "' LIMIT 1;"; if( $row = $this->DBDrive->ExecuteQuery($query, $FetchResults=TRUE) ) { return $row; } else { return FALSE; } } else { throw new Exception('Books - ReturnInfo - id not valid.'); } } Then i have another method PrintInfo function PrintInfo($id) { print_r( $this->ReturnInfo($id) ); } Obviously the code sample are just for example and not actual production code. In the second method should I check (again) if id is numeric ? Or can I skip it because is already taken care in the first method and if it's not an exception will be thrown? Till now I always wrote code with redundant checks (no matter if already checked elsewhere i'll check it also here) Is there a best practice? Is just common sense? Thank you in advance for your kind replies.

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• Best practice when removing entity regarding mappedBy collections?

  - by Daniel Bleisteiner

  I'm still kind of undecided which is the best practice to handle em.remove(entity) with this entity being in several collections mapped using mappedBy in JPA. Consider an entity like a Property that references three other entities: a Descriptor, a BusinessObject and a Level entity. The mapping is defined using @ManyToOne in the Property entity and using @OneToMany(mappedBy...) in the other three objects. That inverse mapping is defined because there are some situations where I need to access those collections. Whenever I remove a Property using em.remove(prop) this element is not automatically removed from managed entities of the other three types. If I don't care about that and the following page load (webapp) doesn't reload those entities the Property is still found and some decisions might be taken that are no longer true. The inverse mappings may become quite large and though I don't want to use something like descriptor.getProperties().remove(prop) because it will load all those properties that might have been lazy loaded until then. So my currently preferred way is to refresh the entity if it is managed: if (em.contains(descriptor)) em.refresh(descriptor) - which unloads a possibly loaded collection and triggers a reload upon the next access. Is there another feasible way to handle all those mappedBy collections of already loaded entites?

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• Safe way for getting/finding a vertex in a graph with custom properties -> good programming practice

  - by Shadow

  Hi, I am writing a Graph-class using boost-graph-library. I use custom vertex and edge properties and a map to store/find the vertices/edges for a given property. I'm satisfied with how it works, so far. However, I have a small problem, where I'm not sure how to solve it "nicely". The class provides a method Vertex getVertex(Vertexproperties v_prop) and a method bool hasVertex(Vertexproperties v_prop) The question now is, would you judge this as good programming practice in C++? My opinion is, that I have first to check if something is available before I can get it. So, before getting a vertex with a desired property, one has to check if hasVertex() would return true for those properties. However, I would like to make getVertex() a bit more robust. ATM it will segfault when one would directly call getVertex() without prior checking if the graph has a corresponding vertex. A first idea was to return a NULL-pointer or a pointer that points past the last stored vertex. For the latter, I haven't found out how to do this. But even with this "robust" version, one would have to check for correctness after getting a vertex or one would also run into a SegFault when dereferencing that vertex-pointer for example. Therefore I am wondering if it is "ok" to let getVertex() SegFault if one does not check for availability beforehand?

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• Programming Practice

  - by deepti

  public DataTable UserUpdateTempSettings(int install_id, int install_map_id, string Setting_value,string LogFile) { SqlConnection oConnection = new SqlConnection(sConnectionString); DataSet oDataset = new DataSet(); DataTable oDatatable = new DataTable(); SqlDataAdapter MyDataAdapter = new SqlDataAdapter(); try { oConnection.Open(); cmd = new SqlCommand("SP_HOTDOC_PRINTTEMPLATE_PERMISSION", oConnection); cmd.Parameters.Add(new SqlParameter ("@INSTALL_ID", install_id)); cmd.Parameters.Add(new SqlParameter ("@INSTALL_MAP_ID", install_map_id)); cmd.Parameters.Add(new SqlParameter("@SETTING_VALUE", Setting_value)); if (LogFile != "") { cmd.Parameters.Add(new SqlParameter("@LOGFILE",LogFile)); } cmd.CommandType = CommandType.StoredProcedure; MyDataAdapter.SelectCommand = cmd; cmd.ExecuteNonQuery(); MyDataAdapter.Fill(oDataset); oDatatable = oDataset.Tables[0]; return oDatatable; } catch (Exception ex) { Utils.ShowError(ex.Message); return oDatatable; } finally { if ((oConnection.State != ConnectionState.Closed) || (oConnection.State != ConnectionState.Broken)) { oConnection.Close(); } oDataset = null; oDatatable = null; oConnection.Dispose(); oConnection = null; } } i have used execute non query.. normally its not used with data adapter... if iam not using its giving me error.. is it bad programming practice to use execute non query with data adapter

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• Hibernate Performance Best Practice?

  - by user829237

  Im writing a Web application using Hibernate 3. So, after a while i noticed that something was slow. So i tested hibernate profiler and found that hibernate will make unreasonably many db-calls for simple operation. The reason is ofcourse that i load an Object (this object has several "parents") and these "parents" have other "parents". So basicly hibernate loads them all, even though i just need the basic object. Ok, so i looked into lazy-loading. Which lead me into the Lazyloading-exception, because i have a MVC webapp. So now i'm a bit confused as to what is my best approach to this. Basicly all I need is to update a single field on an object. I already have the object-key. Should I: 1. Dig into Lazy-loading. And then rewrite my app for a open-session-view? 2. Dig into lazy-loading. And then rewrite my dao's to be more specific. E.g. writing DAO-methods that will return objects instanciated with only whats necessary for each use-case? Could be a lot of extra methods... 3. Scratch hibernate and do it myself? 4. Cant really think of other solutions right now. Any suggestions? What is the best practice?

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• JS best practice for member functions

  - by MickMalone1983

  I'm writing a little mobile games library, and I'm not sure the best practice for declaring member functions of instantiated function objects. For instance, I might create a simple object with one property, and a method to print it: function Foo(id){ this.id = id; this.print = function(){ console.log(this.id); }; }; However, a function which does not need access to 'private' members of the function does not need to be declared in the function at all. I could equally have written: function print(){ console.log(this.id); }; function Foo(id){ this.id = id; this.print = print; }; When the function is invoked through an instance of Foo, the instance becomes the context for this, so the output is the same in either case. I'm not entirely sure how memory is allocated with JS, and I can't find anything that I can understand about something this specific, but it seems to me that with the first example all members of Foo, including the print function, are duplicated each time it is instantiated - but with the second, it just gets a pointer to one, pre-declared function, which would save any more memory having to be allocated as more instances of Foo are created. Am I correct, and if I am, is there any memory/performance benefit to doing this?

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• Created User in Linux (Ubuntu) Without Creating a Home Directory - Causing Problems

  - by nicorellius

  This may be a rookie mistake, but I created a user (new user) in Linux on a Ubuntu system and didn't actually create the home directory for this user. Now, when I log in, it says there are problems... If I delete the path home/<new user> and try to log in the system tells me I can use root as home directory but I will likely experience problems, and then it won't let me log in. What is the best way to create this directory with the appropriate permissions? Should I just create another user and delete this one? I need some help...

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• dell u2410 3dMark Benchmark distortion problems

  - by Scanningcrew

  Ive been doing burn in testing for a new system I have put together and I am running into some video distortion problems with running the 3DMark benchmark tools (Both 06 and Vantage). The graphics will be fine, then sometimes during a test switch the screen will light up with thin horizontal ranibow lines (Something that looks very "glitchy") If i turn the monitor off and back on it clears up. All the tests "pass" and my system gets good marks but it concerns me if I might have problems with games (The screen returns to normal if I dont resest monitor and just let tests pass). I want to return a problem component now before its too late if it is something with the new hardware. Also, I am monitoring temp with thermal laser gun and the card itself is not going above 65c. Any ideas? System: Asrock x58 Xtreme - Last BIOS (1.80) EVGA Geforce GTX 285 w/ latest nvidia drivers (Connect via DVI1) Dell U2410(Set to 59hz refresh 1900x1202 -although I believe benchmarks run 1200x1024) Windows 7 Ultimate 64 12Gb DDR3 1600 RAM

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• Problems with Adobe Flash

  - by Georg Scholz

  I'm running Windows 7, 64-Bit on a Core-i5 HP Notebook. For approximately the last 3 months, I've had major problems with Adobe Flash. Flash has been uninstalled and installed again multiple times. No changes. Here is what happens in different browsers: (All browsers are in the latest version as of this post) Firefox: Doesn't work at all. This bothers me most, since FF is my favorite browser; I'm using a lot of Plugins. Have tried to de-activate all Plugins, but no change. IE and Chrome: Works, but most pages with Flash are stuck during page load for ~30 seconds. After that, everything is fine. Opera: No problems, everything working as it should. Strange, eh? Any help is highly appreciated!

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• Problems serving SVN over HTTPS on Ubuntu 10.04

  - by odd parity

  We've been experiencing some problems with our Subversion server after upgrading to Ubuntu 10.04. When trying to access a repository, regardless of client (I've tried git-svn and svn on Windows as well as svn on Ubuntu 10.04, from different computers and network locations), I get a 400 bad request. Here's the output from svn: svn: Server sent unexpected return value (400 Bad Request) in response to OPTIONS request for 'https://svn.example.org/svn/programs' Here are the relevant entries from the Apache logs (I'm running Apache 2.2): error.log [Mon Jun 14 11:29:31 2010] [error] [client x.x.x.x] request failed: error reading the headers ssl_access.log x.x.x.x - - [14/Jun/2010:11:29:28 +0200] "OPTIONS /svn/programs HTTP/1.1" 401 2643 "-" "SVN/1.6.6 (r40053) neon/0.29.0" x.x.x.x - - [14/Jun/2010:11:29:31 +0200] "ction-set/></D:options>OPTIONS /svn/programs HTTP/1.1" 400 644 "-" "SVN/1.6.6 (r40053) neon/0.29.0" If anyone has run into similar problems or could give me a pointer to track down the cause of this I'd be very grateful - I'd really like to avoid having to downgrade the box again.

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• Windows xp problems

  - by anca

  I had problems with web virus cake 3.00 and I downloaded Malwarebytes Anti-WALWARE, I got rid of that virus but I did other problems. When I open my PC appears to skype error "exception in module Skype.exe at 0013CE7D.The EOleSysError RPC server is unavailable" and another one "Error in C: \ WINDOWS \ system32 \ Nvcpl.Dll Missing entry: NnStartup" when I install / uninstall a program says "Windows Installer service Could you not be accessed. This CAN occure if you are running Windows in safe mode, or if the Windows Installer is not corectly installes. Contact your support personnel for assistance. I have tried many "solutions" but nothing worked. Please HELP! It windows xp sp 2

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• Internet problems

  - by dan

  I've got problems on my freshly installed windows Xp machine. I cannot connect to the internet and I've tried various 'solutions' provided to me by the help and support center. Surprisingly none of them worked... Anyways, I've got 3 pc's next to me sharing a lan which is connected to the internet though a modem. The computer I use right now uses windows xp aswell and runs without any problems. I've tried everything on not working computer. I've ran the connection wizard several times, but it's not working :( Also I've very little experience with this version of windows, so I'm sorry if the solution is obvious.

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• Ubuntu 10.04 problems - GVIM and Sound

  - by Skun

  Hey Guys ! Well, i have 2 problems .. not exactly problems, but one is a question, and the other is a problem . QUESTION I have installed gVim on my laptop and now i want to install plugins and customize my vimrc . Where is the 'plugin' , 'color' , 'docs' directory located in order for me to drop those files in ? And where do i need to put the .vimrc file for gVim to be able to recogonize it ? PROBLEM Sound isn't working. I dont know whats the problem @ all. It just doesnt play . And NO its not on mute. i Checked. If any other input is required from the terminal , please ask for it. I'm kinda a n00b in all this. Please help. Thanks in advance

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• Injecting jms resource in servlet & best practice for MDB

  - by kislo_metal

  using ejb 3.1, servlet 3.0 (glassfish server v3) Scenario: I have MDB that listen to jms messages and give processing to some other session bean (Stateless). Servelet injecting jms resource. Question 1: Why servlet can`t inject jms resources when they use static declaration ? @Resource(mappedName = "jms/Tarturus") private static ConnectionFactory connectionFactory; @Resource(mappedName = "jms/StyxMDB") private static Queue queue; private Connection connection; and @PostConstruct public void postConstruct() { try { connection = connectionFactory.createConnection(); } catch (JMSException e) { e.printStackTrace(); } } @PreDestroy public void preDestroy() { try { connection.close(); } catch (JMSException e) { e.printStackTrace(); } } The error that I get is : [#|2010-05-03T15:18:17.118+0300|WARNING|glassfish3.0|javax.enterprise.system.container.web.com.sun.enterprise.web|_ThreadID=35;_ThreadName=Thread-1;|StandardWrapperValve[WorkerServlet]: PWC1382: Allocate exception for servlet WorkerServlet com.sun.enterprise.container.common.spi.util.InjectionException: Error creating managed object for class ua.co.rufous.server.services.WorkerServiceImpl at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.createManagedObject(InjectionManagerImpl.java:312) at com.sun.enterprise.web.WebContainer.createServletInstance(WebContainer.java:709) at com.sun.enterprise.web.WebModule.createServletInstance(WebModule.java:1937) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1252) Caused by: com.sun.enterprise.container.common.spi.util.InjectionException: Exception attempting to inject Unresolved Message-Destination-Ref ua.co.rufous.server.services.WorkerServiceImpl/[email protected]@null into class ua.co.rufous.server.services.WorkerServiceImpl at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl._inject(InjectionManagerImpl.java:614) at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.inject(InjectionManagerImpl.java:384) at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.injectInstance(InjectionManagerImpl.java:141) at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.injectInstance(InjectionManagerImpl.java:127) at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.createManagedObject(InjectionManagerImpl.java:306) ... 27 more Caused by: com.sun.enterprise.container.common.spi.util.InjectionException: Illegal use of static field private static javax.jms.Queue ua.co.rufous.server.services.WorkerServiceImpl.queue on class that only supports instance-based injection at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl._inject(InjectionManagerImpl.java:532) ... 31 more |#] my MDB : /** * asadmin commands * asadmin create-jms-resource --restype javax.jms.ConnectionFactory jms/Tarturus * asadmin create-jms-resource --restype javax.jms.Queue jms/StyxMDB * asadmin list-jms-resources */ @MessageDriven(mappedName = "jms/StyxMDB", activationConfig = { @ActivationConfigProperty(propertyName = "connectionFactoryJndiName", propertyValue = "jms/Tarturus"), @ActivationConfigProperty(propertyName = "acknowledgeMode", propertyValue = "Auto-acknowledge"), @ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue") }) public class StyxMDB implements MessageListener { @EJB private ActivationProcessingLocal aProcessing; public StyxMDB() { } public void onMessage(Message message) { try { TextMessage msg = (TextMessage) message; String hash = msg.getText(); GluttonyLogger.getInstance().writeInfoLog("geted jms message hash = " + hash); } catch (JMSException e) { } } } everything work good without static declaration: @Resource(mappedName = "jms/Tarturus") private ConnectionFactory connectionFactory; @Resource(mappedName = "jms/StyxMDB") private Queue queue; private Connection connection; Question 2: what is the best practice for working with MDB : processing full request in onMessage() or calling another bean(Stateless bean in my case) in onMessage() method that would process it. Processing including few calls to soap services, so the full processing time could be for a 3 seconds. Thank you.

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• Best Practice for Images with Codeigniter : Generating Thumbs or Resizing on the Fly

  - by Steve K

  Hi all, I know there’s been a good deal written on thumbnail generation and the like with CI, but I wanted to explain what I’ve made and see what kind of best-practice advice I could find. Here’s my story… Currently, I have a site which allows users to upload collections of photos to projects they’ve created after first creating an account. Upon account creation, the site generates folders for the users in the following fashion for each of five pre-defined projects: /students/username/project_num/images/thumbs/ (This is to say that within a pre-created students folder, the username, project_num, images and thumbs folders are created recursively five times.) When a user uploads images to a project, I have a gallery controller which uploads the full images into the images folder for the project_num, and then creates a smaller thumbnail which maintains its ratio. So far so good. On the index page of the site, where these thumbnails and full images are displayed, I had a bit of a brain lapse, thinking I could simply output the full image while resizing it via css for a ‘medium-size’ image which would lead to the full-size image when clicked. (To be clear, the path is: Click on thumbnail— Load scaled full-size (medium-size) image via ajax into a display area above thumbs— Click on medium-sized image— Load full size image via lightbox, or something of that nature.) I have everything working to this point, except, as one might imagine, resizing the full-sized images with css doesn’t maintain aspect ratio for the thumbs, which means I need to find the best way to resize these. In thinking about it, I figured I had two options: I could resize the image on the fly when the user clicks a thumbnail to load the medium-sized image via ajax. (I have a method ‘get_image($url)’ in my gallery controller which simply loads a view with an image tag and the image source passed to it, etc.) I thought perhaps I could send it first to my gallery model, resize it there on the fly, and send it on to the view. The problem I’m having is that resizing it on the fly and echoing it out gives me the raw image data (I apologize, I don’t know that’s the right term). I’ve tried using data_uris to format the raw data into something echoable, but with no success. Is this method possible? The second option I considered was to generate a second medium-sized thumbnail when the user uploads the image with maintain_ratio set to true. This method is slightly less ideal, given that when providing a way for the user to delete their projects, I’ll need to scan for an additional set of images to delete. Not a huge deal, definitely, but something I figured could be avoided by generating the medium-sized image on the fly. I hope I’ve been clear in my explanations, if long-winded! I’m very curious to see what suggestions folks have about the best way to handle this. Much thanks for reading, and any suggestions are much-appreciated! Steve K.

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• Real World Examples of read-write in concurrent software

  - by Richard Fabian

  I'm looking for real world examples of needing read and write access to the same value in concurrent systems. In my opinion, many semaphores or locks are present because there's no known alternative (to the implementer,) but do you know of any patterns where mutexes seem to be a requirement? In a way I'm asking for candidates for the standard set of HARD problems for concurrent software in the real world.

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• Best practice to structure large html-based project

  - by AntonAL

  I develop Rails based website, enjoying using partials for some common "components" Recently, i faced a problem, that states with CSS interference. Styles for one component (described in css) override styles for another components. For example, one component has ... <ul class="items"> ... and another component has it too. But that ul's has different meaning in these two components. On the other hand, i want to "inherit" some styles for one component from another. For example: Let, we have one component, called "post" <div class="post"> <!-- post's stuff --> <ul class="items"> ... </ul> </div And another component, called "new-post": <div class="new-post"> <!-- post's stuff --> <ul class="items"> ... </ul> <!-- new-post's stuff --> <div class="tools">...</div> </div Post and new-post have something similar ("post's stuff") and i want to make CSS rules to handle both "post" and "new-post" New post has "subcomponents", for example - editing tools, that has also: <ul class="items"> This is where CSS rules starting to interfer - some rules, targeted for ul.items (in post and new-post) applies subcomponent of new-post, called "tools" On the one hand - i want to inherit some styles On the other hand, i want to get better incapsulation What are the best practices, to avoid such kind of problems ?

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