Search Results

Search found 8692 results on 348 pages for 'patterns practices'.

Page 120/348 | < Previous Page | 116 117 118 119 120 121 122 123 124 125 126 127  | Next Page >

  • How to connect remote EJB module from application client

    - by Zeck
    Hi guys, I have a EJB module in remote Glassfish server and application client in my computer. I want to connect from the application client to the remote EJB. Here is the my EJB interface: @Remote public interface BookEJBRemote { public String getTitle(); } Here is the my ejb: @Stateless public class BookEJB implements BookEJBRemote { @Override public String getTitle() { return "Twenty Thousand Leagues Under the Sea"; } } I have several questions : Can I use Dependency Injection in the remote application client to connect to the ejb? If so what can i do to achieve this. Do i need to configure in the sun-ejb-jar.xml and sun-application-client.xml? In other words, if i use DI like @EJB MyEJBRemote ejb; How application client container know what ejb to be injected? Where should i specify the information? How can i run the application client? I tried to run package-appclient in the glassfish server to get appclient.jar and copy it to my computer. Then i type appclient.jar -client myAppClient.jar . It didn't work. How do i point the target server? if i cannot use DI in the client then i guess i have to use JNDI lookup. Do i need to configure jndi name in sun-ejb-jar.xml or in the sun-application-client.xml? No matter how i try i never manage to run application client ? Can you guys put some working example? And thank you for every advises and examples?

    Read the article

  • What are the Worst Software Project Failures Ever?

    - by Warren P
    Is there a good list of "worst software project failures ever" in the history of software development? For example in Canada a "gun registry" project spent around two billion dollars. (http://en.wikipedia.org/wiki/Gun_registry). This is of course, insane, even if the final product "sort of worked". I have heard of an FBI Case file system which there have been several attempts to rewrite, all of them so far, failures. There is a book on the subject (Software Runaways). There doesn't seem to be be a software "boondoggle" list or "fiasco" list on Wikipedia that I can see. (Update: Therac-25 would be the 'winner' of this question, except that I was internally thinking more of Software projects that had as their deliverable, mainly software, as opposed to firmware projects like Therac-25, where the hardware and firmware together are capable of killing people. In terms of pure software monetary debacles, which was my intended question, there are several contenders.)

    Read the article

  • Maintain List of Active Users for Web

    - by Bryan Marble
    Problem Statement - Would like to know if particular web app user is active (i.e. logged in and using site) and be able to query for list of active users or determine a user's activity status. Constraints - Doesn't need to be exact (i.e. if a user was active within a certain timeframe, that's ok to say that they're active even if they've closed their browser). I feel like there should be a design pattern for this type of problem but haven't been able to find anything here or elsewhere on the web. Approaches I'm considering: Maintain a table that is updated any time a user performs an action (or some subset of actions). Would then query for users that have performed an action within some threshold of time. Try to monitor session information and maintain a table that lists logged in users and times out after a certain period of time. Some other more standard way of doing this? How would you approach this problem (again, from a design pattern perspective)? Thanks!

    Read the article

  • Common programming mistakes for Scala developers to avoid

    - by jelovirt
    In the spirit of Common programming mistakes for Java developers to avoid? Common programming mistakes for JavaScript developers to avoid? Common programming mistakes for .NET developers to avoid? Common programming mistakes for Haskell developers to avoid? Common programming mistakes for Python developers to avoid? Common Programming Mistakes for Ruby Developers to Avoid Common programming mistakes for PHP developers to avoid? what are some common mistakes made by Scala developers, and how can we avoid them? Also, as the biggest group of new Scala developers come from Java, what specific pitfalls they have to be aware of? For example, one often cited problem Java programmers moving to Scala make is use a procedural approach when a functional one would be more suitable in Scala. What other mistakes e.g. in API design newcomers should try to avoid.

    Read the article

  • Controls added in the designer are null during Page_Load

    - by mwright
    All of the names below are generic and not the actual names used. I have a custom UserControl with a Panel that contains a a couple Labels, both .aspx controls. .aspx: <asp:Panel runat="server"> <asp:Label ID="label1" runat="server"> </asp:Label> </asp:Panel> <asp:Panel runat="server"> <asp:Label ID="label2" runat="server"> </asp:Label> </asp:Panel> Codebehind: private readonly Object object; protected void Page_Load(object sender, EventArgs e) { // These are the lines that are failing // label1 and label2 are null label1.Text = object.Value1; label2.Text = object.Value2; } public ObjectRow(Object objectToDisplay) { object = objectToDisplay; } On another page, in the code behind, I create a new instance of the custom user control. protected void Page_Load(object sender, EventArgs e) { CustomControl control = new CustomControl(object); } The user control takes the parameter and attempts to set the labels based off of the object passed in. The labels that it tries to assign the values to are however, null. Is this an ASP.net lifecycle issue that I'm not understanding? My understanding based on the Microsoft ASP.net lifecycle page was that page controls were available after the Page_Initialization. What is the proper way to do this? Is there a better way?

    Read the article

  • How to avoid using this in a constructor

    - by Paralife
    I have this situation: interface MessageListener { void onMessageReceipt(Message message); } class MessageReceiver { MessageListener listener; public MessageReceiver(MessageListener listener, other arguments...) { this.listener = listener; } loop() { Message message = nextMessage(); listener.onMessageReceipt(message); } } and I want to avoid the following pattern: (Using the this in the Client constructor) class Client implements MessageListener { MessageReceiver receiver; MessageSender sender; public Client(...) { receiver = new MessageReceiver(this, other arguments...); sender = new Sender(...); } . . . @Override public void onMessageReceipt(Message message) { if(Message.isGood()) sender.send("Congrtulations"); else sender.send("Boooooooo"); } } The reason why i need the above functionality is because i want to call the sender inside the onMessageReceipt() function, for example to send a reply. But I dont want to pass the sender into a listener, so the only way I can think of is containing the sender in a class that implements the listener, hence the above resulting Client implementation. Is there a way to achive this without the use of 'this' in the constructor? It feels bizare and i dont like it, since i am passing myself to an object(MessageReceiver) before I am fully constructed. On the other hand, the MessageReceiver is not passed from outside, it is constructed inside, but does this 'purifies' the bizarre pattern? I am seeking for an alternative or an assurance of some kind that this is safe, or situations on which it might backfire on me.

    Read the article

  • when to use the abstract factory pattern?

    - by hguser
    Hi: I want to know when we need to use the abstract factory pattern. Here is an example,I want to know if it is necessary. The UML THe above is the abstract factory pattern, it is recommended by my classmate. THe following is myown implemention. I do not think it is necessary to use the pattern. And the following is some core codes: package net; import java.io.IOException; import java.util.HashMap; import java.util.Map; import java.util.Properties; public class Test { public static void main(String[] args) throws IOException, InstantiationException, IllegalAccessException, ClassNotFoundException { DaoRepository dr=new DaoRepository(); AbstractDao dao=dr.findDao("sql"); dao.insert(); } } class DaoRepository { Map<String, AbstractDao> daoMap=new HashMap<String, AbstractDao>(); public DaoRepository () throws IOException, InstantiationException, IllegalAccessException, ClassNotFoundException { Properties p=new Properties(); p.load(DaoRepository.class.getResourceAsStream("Test.properties")); initDaos(p); } public void initDaos(Properties p) throws InstantiationException, IllegalAccessException, ClassNotFoundException { String[] daoarray=p.getProperty("dao").split(","); for(String dao:daoarray) { AbstractDao ad=(AbstractDao)Class.forName(dao).newInstance(); daoMap.put(ad.getID(),ad); } } public AbstractDao findDao(String id) {return daoMap.get(id);} } abstract class AbstractDao { public abstract String getID(); public abstract void insert(); public abstract void update(); } class SqlDao extends AbstractDao { public SqlDao() {} public String getID() {return "sql";} public void insert() {System.out.println("sql insert");} public void update() {System.out.println("sql update");} } class AccessDao extends AbstractDao { public AccessDao() {} public String getID() {return "access";} public void insert() {System.out.println("access insert");} public void update() {System.out.println("access update");} } And the content of the Test.properties is just one line: dao=net.SqlDao,net.SqlDao So any ont can tell me if this suitation is necessary?

    Read the article

  • To be effective on your home projects is it better using the same technologies used at work?

    - by systempuntoout
    To be more productive and effective, is it better to start developing an home project using the same technologies used at work? I'm not talking about a simple hello world web page but an home project with all bells and whistles that one day, maybe, you could sell on internet. This dilemma is often subject of flames between me and a friend. He thinks that if you want to make a great home-made project you need to use the same technologies used daily at work staying in the same scope too; for example, a c++ computer game programmer should develope an home-made c++ game. I'm pretty sure that developing using the same technologies used at work can be more productive at beginning, but surely less exciting and stimulating of working with other languages\ides\libraries out of your daily job. What's your opinion about that?

    Read the article

  • Explaining to boss why we need to avoid horizontal scroll

    - by Bradley Herman
    I need help explaining to my boss why her design is poor on a clients website. She has no knowledge of web and it can be difficult as a web developer working with a woman who is a graphic designer (not even a web designer really). On a current site she has designed, an image bar "needs" to be like 1200px according to her, though it isn't necessary with the content. I'll show a quick sketch to illustrate what's going on: http://imgur.com/MNGOT.jpg As you see, the banner spills out past the 960px of the content and as wide as 1200px. This creates a horizontal scroll when all the content is viewable within the 960px wide viewport. I need to make this an img and not a css background because it's a jquery slideshow that fades from image to image. I think this is a big problem because a lot of people are going to get a horizontal scroll bar imposed in their browser when they're still able to see all the relevant content. How do I help her explain it. She thinks no one will notice and it'll be fine, I think it's very bad practice and confusing to the end user. Any help?

    Read the article

  • Exception design: Custom exceptions reading data from file?

    - by User
    I have a method that reads data from a comma separated text file and constructs a list of entity objects, let's say customers. So it reads for example, Name Age Weight Then I take these data objects and pass them to a business layer that saves them to a database. Now the data in this file might be invalid, so I'm trying to figure out the best error handling design. For example, the text file might have character data in the Age field. Now my question is, should I throw an exception such as InvalidAgeException from the method reading the file data? And suppose there is length restriction on the Name field, so if the length is greater than max characters do I throw a NameTooLongException or just an InvalidNameException, or do I just accept it and wait until the business layer gets a hold of it and throw exceptions from there? (If you can point me to a good resource that would be good too)

    Read the article

  • Is there a compelling reason to use quantifiers in Perl regular expressions instead of just repeatin

    - by Morinar
    I was performing a code review for a colleague and he had a regular expression that looked like this: if ($value =~ /^\d\d\d\d$/) { #do stuff } I told him he should change it to: if ($value =~ /^\d{4}$/) { #do stuff } To which he replied that he preferred the first for readability (I find the second more readable, but that's a religious debate I'll save for another day). My question: is there an actual benefit to one over the other?

    Read the article

  • How to handle input and parameter validation between layers?

    - by developr
    If I have a 3 layer web forms application that takes user input, I know I can validate that input using validation controls in the presentation layer. Should I also validate in the business and data layers as well to protect against SQL injection and also issues? What validations should go in each layer? Another example would be passing a ID to return a record. Should the data layer ensure that the id is valid or should that happen in BLL / UI?

    Read the article

  • HELP!! Ruby & RoR Resources?

    - by aaroninfidel
    Hello, I've been a PHP Developer for a few years now and I've recently been interested in learning Ruby & Rails but I've found a lot of the resources I've found seem to be dated and not for Rails 2.0 or Ruby 1.8.6 etc... can anyone point me in the right direction? I'm running OSX 10.6 with the default ruby & rails installation. Thanks!

    Read the article

  • Interface and partial classes

    - by Tomek Tarczynski
    According to rule SA1201 in StyleCop elements in class must appear in correct order. The order is following: Fields Constructors Finalizers (Destructors) Delegates Events Enums Interfaces Properties Indexers Methods Structs Classes Everything is ok, except of Interfaces part, because Interface can contain mehtods, events, properties etc... If we want to be strict about this rule then we won't have all members of Interface in one place which is often very useful. According to StyleCop help this problem can be solved by spliting class into partial classes. Example: /// <summary> /// Represents a customer of the system. /// </summary> public partial class Customer { // Contains the main functionality of the class. } /// <content> /// Implements the ICollection class. /// </content> public partial class Customer : ICollection { public int Count { get { return this.count; } } public bool IsSynchronized { get { return false; } } public object SyncRoot { get { return null; } } public void CopyTo(Array array, int index) { throw new NotImplementedException(); } } Are there any other good solutions to this problem?

    Read the article

  • What is your strategy to avoid dynamic typing errors in Python (NoneType has not attribute x)?

    - by Koen Bok
    Python is one of my favorite languages, but I really have a love/hate relationship with it's dynamicness. Apart from the advantages, it often results in me forgetting to check a type, trying to call an attribute and getting the NoneType (or any other) has no attribute x error. A lot of them are pretty harmless but if not handled correctly they can bring down your entire app/process/etc. Over time I got better predicting where these could pop up and adding explicit type checking, but because I'm only human I miss one occasionally and then some end-user finds it. So I'm interested in your strategy to avoid these. Do you use type-checking decorators? Maybe special object wrappers? Please share...

    Read the article

  • "Nearly divisible"

    - by bobobobo
    I want to check if a floating point value is "nearly" a multiple of 32. E.g. 64.1 is "nearly" divisible by 32, and so is 63.9. Right now I'm doing this: #define NEARLY_DIVISIBLE 0.1f float offset = fmodf( val, 32.0f ) ; if( offset < NEARLY_DIVISIBLE ) { // its near from above } // if it was 63.9, then the remainder would be large, so add some then and check again else if( fmodf( val + 2*NEARLY_DIVISIBLE, 32.0f ) < NEARLY_DIVISIBLE ) { // its near from below } Got a better way to do this?

    Read the article

  • Representing game states in Tic Tac Toe

    - by dacman
    The goal of the assignment that I'm currently working on for my Data Structures class is to create a of Quantum Tic Tac Toe with an AI that plays to win. Currently, I'm having a bit of trouble finding the most efficient way to represent states. Overview of current Structure: AbstractGame Has and manages AbstractPlayers (game.nextPlayer() returns next player by int ID) Has and intializes AbstractBoard at the beginning of the game Has a GameTree (Complete if called in initialization, incomplete otherwise) AbstractBoard Has a State, a Dimension, and a Parent Game Is a mediator between Player and State, (Translates States from collections of rows to a Point representation Is a StateConsumer AbstractPlayer Is a State Producer Has a ConcreteEvaluationStrategy to evaluate the current board StateTransveralPool Precomputes possible transversals of "3-states". Stores them in a HashMap, where the Set contains nextStates for a given "3-state" State Contains 3 Sets -- a Set of X-Moves, O-Moves, and the Board Each Integer in the set is a Row. These Integer values can be used to get the next row-state from the StateTransversalPool SO, the principle is Each row can be represented by the binary numbers 000-111, where 0 implies an open space and 1 implies a closed space. So, for an incomplete TTT board: From the Set<Integer> board perspective: X_X R1 might be: 101 OO_ R2 might be: 110 X_X R3 might be: 101, where 1 is an open space, and 0 is a closed space From the Set<Integer> xMoves perspective: X_X R1 might be: 101 OO_ R2 might be: 000 X_X R3 might be: 101, where 1 is an X and 0 is not From the Set<Integer> oMoves perspective: X_X R1 might be: 000 OO_ R2 might be: 110 X_X R3 might be: 000, where 1 is an O and 0 is not Then we see that x{R1,R2,R3} & o{R1,R2,R3} = board{R1,R2,R3} The problem is quickly generating next states for the GameTree. If I have player Max (x) with board{R1,R2,R3}, then getting the next row-states for R1, R2, and R3 is simple.. Set<Integer> R1nextStates = StateTransversalPool.get(R1); The problem is that I have to combine each one of those states with R1 and R2. Is there a better data structure besides Set that I could use? Is there a more efficient approach in general? I've also found Point<-State mediation cumbersome. Is there another approach that I could try there? Thanks! Here is the code for my ConcretePlayer class. It might help explain how players produce new states via moves, using the StateProducer (which might need to become StateFactory or StateBuilder). public class ConcretePlayerGeneric extends AbstractPlayer { @Override public BinaryState makeMove() { // Given a move and the current state, produce a new state Point playerMove = super.strategy.evaluate(this); BinaryState currentState = super.getInGame().getBoard().getState(); return StateProducer.getState(this, playerMove, currentState); } } EDIT: I'm starting with normal TTT and moving to Quantum TTT. Given the framework, it should be as simple as creating several new Concrete classes and tweaking some things.

    Read the article

  • What should a developer know before building a public web site?

    - by Joel Coehoorn
    What things should a programmer implementing the technical details of a web site address before making the site public? If Jeff Atwood can forget about HttpOnly cookies, sitemaps, and cross-site request forgeries all in the same site, what important thing could I be forgetting as well? I'm thinking about this from a web developer's perspective, such that someone else is creating the actual design and content for the site. So while usability and content may be more important than the platform, you the programmer have little say in that. What you do need to worry about is that your implementation of the platform is stable, performs well, is secure, and meets any other business goals (like not cost too much, take too long to build, and rank as well with Google as the content supports). Think of this from the perspective of a developer who's done some work for intranet-type applications in a fairly trusted environment, and is about to have his first shot and putting out a potentially popular site for the entire big bad world wide web. Also: I'm looking for something more specific than just a vague "web standards" response. I mean, HTML, JavaScript, and CSS over HTTP are pretty much a given, especially when I've already specified that you're a professional web developer. So going beyond that, Which standards? In what circumstances, and why? Provide a link to the standard's specification. This question is community wiki, so please feel free to edit that answer to add links to good articles that will help explain or teach each particular point.

    Read the article

  • Refactoring a C# derived class with method dependancies

    - by drelihan
    Hi Folks, I want to get your opinion on this. I have a class which is derived from a base class. I don't have control over the code in the base class and it is critical to the system that I derive from it. In my class I inherite two methods that are critical to the system and are used in pretty much every function, many times. I intend to refactor this derived class and extract some classes from it - this won't be a problem. What I'm not sure about is, is it worth extracting class if I have to constantly make call backs to my main class to access the two methods (or public wrappers to the methods)??? Thanks

    Read the article

  • Best practice for DAO pattern ?

    - by Tony
    I've seen a lot of codes use a service-dao pattern , I don't know the origin of this pattern . It force the front layer call service , then delegates some of the service task to dao. I want to ask : Does DAO layer do purely data access related task ? What about exception encapsulation ? Is there other pattern can be used to replace this ?

    Read the article

< Previous Page | 116 117 118 119 120 121 122 123 124 125 126 127  | Next Page >