hi,i have a class which have to perfom somes processes on a set of object.i want to know if it's better to extend HashSet (by exple) or to use it in my classe as a private attribute.thanx in advance. badr.

Research into xp, Your ThoughtsI am a student researching into Extream programing. i am to create a development tool that will help people co-ordinate their xp projects. therfore i need help from the people who use XP or have chosen against using it. What i need to know is if there are any ...

I started to write a chat application [server + client]and I wanted to optimise it [good OOP + reuse of classes,objects].So, I have a class that handles the interface, a class that handles the socket [reading, writing], a class that handles the events, etc...As Iwanted to write it the best way ...

Hello,everybody!I am looking for ejb frameworks,can anyone introduce some to me?

Hi!I'm doing master thesis about defining software development methdod/process to my company. I'm very in the beginning in this but I have decided to concentrate on so called 'agile methods'.But now I'm asking does someone knows good source material where is described implementation of ...

Hi,How can you adapt the servicelocator pattern so that it enables the lookup of EJB's on different servers? The problem is that the iiop adress (providerURL) of these beans can vary which means that the InitialContext needs to change. You somehow want to store this (iiop address) in a ...

Dears,I have a friend who is working on our project and he is anOracle DBA. The problem is that he's been very stubborn when itcomes to the app's business rules. He insists that all of thebusiness rules should be inside the database, represented bytriggers, stored procedures and the ...

Dear all,1. Component has a clear seperation between the specification and implementation? I can't understand here.The interface define some operations,but eventually we need coding to realize it. Where is the speration? A class also has methods and coding to realize it. But why we never say a ...

As i understand value objects can be simple java beans or any collection also.I am using java beans as value objects but some of my beans are really big (having large number of properties)....is that bad design.

hello,i have a question concerning the translation of an entity relationship model to an object orientated model:when i have two tables, e.g. "customer" and "contract", where the contract table has a foreign key "customerid" to take the 1:n relationship into account - how do i have to design my ...

Does anyone know of a pattern that is or can be used for managing the rights to data in a database?What I am looking for is to use a pattern that would allow me to easily match up a user with specific data and have some means of checking to see that this user has query rights to that data or ...

I'm just new learners of the UML design .In my design ,my business logic is very few ,so I'm suspect that my design is right or not? Another is in my design should include one to one ,one to many relationship is mostly included .many to many relationship is not included.Please help me,how can ...

I have a design decision to make whether to go for DAO / entity bean?I have identified the domain class which in turn has led me to identify the persisitent objects and ofcourse do the mapping n design the database..Now my question is in my domain class - i have identified 10 tables,so do all ...

Hi all,The question I have here is a very high level one and I'm hoping someone can provide me with some good advice and pointers. I currently have a client desktop application that can access either a local or a remote database. The client app is used to keep track of business clients, ...

Is there any substitution for VIRTUAL FUNCTIONS (C++) in Java ?May be some trick I don't know about?Thanks in advice.

We use Eclipse in our company and are looking for a UML tool.What is better: A plugin or a standalone tool?Or do you have any other ideas (what is important concerning an UML tool)?

Hi all,I齰e three classes: Transaction, Card(Abstract), Credit_Card and Debit_Card. Card is subclass of Transaction and Credit_Card and Debit_Card are subclasses of Card. How do I make to execute a method in the Credit_Card or Debit_Card classes from Transaction class?

Both Bloch and Sun recommend that both checked and unchecked exceptions be documented with the @throws javaodc tag.I have just spent a week editing javaodc, and I have come to a distinct feeling that @throws adds little or no value.Checked exceptions - these are already processed adequately by ...

Hi all,I have implemented Qt's signal and slot here: http://sourceforge.net/projects/javasignalslot/In case you are wondering what's "Qt's signal and slot", please read http://doc.trolltech.com/3.1/signalsandslots.htmlMy version uses String as signal, and the slot can be any public method. ...

Hi all, My java class both extends and implements.To illustrate this in UML do I just use the generalization (arrow) line betweeen classes or is thier another way.Cjheerss

I'm starting to (re)design a workflow engine and was wondering if there were any design resources/examples/ideas that people might know of that would help.Essentially the workflow is a simple state machine with user-invoked transitions.However, it also possesses (multiple) substates and ...

Hi . how return to client large amount of data ?I need build report at client side, I call Session bean that execute query to databaseand need to return data. but the result of query may produse a large amount of data, and trying send it to client cause error out of memory. As I understood all ...

hi,This is for web project. I want to use Session EJBs only, for data access logic i'll write my own normal java DAO classes. I don't want to use entity beans. The session EJBs(containg business logic) will call my DAO classes as any other java class would do. In addition i may have to run ...

I have an EJB which takes input from JSP, and running stored procedure in the database. Because it will run for a long time, its better to run during some schedule hours.After user submit a job from the JSP front, the Stateless Session EJB needs to "wait" until 2:00 AM before it runs the task. ...

Hi,Here my question is I want to search in database and display the record in page. Suppose if I got 100 records in search but I want it to display 20 records in a page, so for 100 records I want it to display in 5 pages. Is it possible to display like that? If possible how it is? Can any body ...

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Consider this:[Actor](USE CASE)[Actor]and[Actor]-->(USE CASE)-->[Actor]I've seen a lot of examples with the format of the first example above, but just a few for the below one.What are the differences?Thanks,Jax

I have a session EJB. Can I use the EJB to run a standalong JAVA program? How? Can anyone give me an example?ThanksKenny

public class Super{ public void doSomethingUseful() { }}public abstract class Sub extends Super{ public abstract void doSomethingUseful();}What is the OO principle behind this?When do we need to override a super class method in subclass as an ...

Hi,Any thoughts on how to approach this issue.I need to populate an array for a Javascript function from a database table, for an information html/JSP page.However, the data changes very infrequently, so I want to avoid the overhead of database lookups every time the page is viewed, but I also ...

Hello!I try to understand how to map JavaCode to UML so I have made a table for it to straighten it out once and for all. at: http://medlem.spray.se/fredand44/umltable.htmlBut now I would like to check with some expert's (you guys) on this area if the table is correct.So I would be most ...

Hi,I'm new in this area and i'd like to know your opinion of which is the best method to learn UML. I've found some books, but the examples are so little....Could you recommend me any site, book, e-learning course... where i can practice with more real examples, including diagrams...?Thanks ...

Can anybody tell me what happens with security when using a Session Fascade ? I identify myelf to the Session Fascade, does it propagate the security information to e.g. an entity bean that is used within the Fascade ?What happens when the Session Fascade starts a transaction ? Does the Entity ...

hey need help with this error. building a web application, everythings runs fine.specs-uses stateful ejbs-using jboss-apache tomcatnow i have a specific bean that opens a connection to our mysql db, and a reference to this bean is passed around.it works fine, however about 15 mins after ...

Hi All,Here is a scenario where all the books suggest. but i dont understand why it should always be like this only. Can any one explain me why is it so.The scenario is something like this. The Entitiy bean take it a BMP or CMP bean not always be accessed directely, instead the Entity bean will ...

Hi Guys, How trustworthy are EJBs when working with Singleton Patterns? 齝ause we've got problems with deadlocks and we thought it could be because of that. Now we're using JBoss 2.4.10. Any idea? Thanx a lot 4 any help.

hii,i am using jboss 3 and have problems with cmr..the problem is that jboss creates a column for each cmr field in the table.a column in the dependent table is also created with name mainTable_columName.how can i avoid creating cmr columns during deployment..aslo where can i specify ...

I'm working on a large project and having a problem about writing an event listener in my application. There are so many swing components and writing an event listener for each component is time consume. So I'm planning to write an adapter class for all or most of my swing components and I ...

Hello!I have a question for this community: which is the best implementation of J2EE Specification ?And what implementation does use Sun ?

Hi all, Anybody know any good worfklow management software out there?If possible free open source products, and already used in production environment.I've researched some open source workflow management products, butso far they are not stable enough.Thank you for your kind ...

Hello.I am not expert in DAO.Should DAO be application specific or not?I mean: the Abstract DAO Factory has all abstract methods to give DAO Objects. e.g. getCustomerDAO(), getAccountDAO() etc... (Banking application). But, can I clutter up Abstract DAO Factory with such more methods from ...

bean> </weblogic-ejb-jar> Inside META-INF directory in test0EJB.jar there is this manifest.mf:Manifest-Version: 1.0 Created-By: 1.3.0_01 (WebGain, Inc.) Class-Path: test1EJB.jar When i execute my client, test0 work but when he call tes1 i have this error:java.rmi.RemoteException: EJB ...

I'm working on a method of an EJB Session Bean. This method has to update data through entity bean (kind of update(...data...) method). When I was trying to update data through this method by using data that cause "SQL unique constraint exception", I got SQLException throwing out.... but what ...

Hi,First, I am an experienced Java programmer who would like to start up a business. I would like to find a good Java programmer who can handle the front end design and implementation for web applications. I have extensive experience concerning server side design, APIs, EJB's, Databases, ...

Hello folks, I'm currently searching tools for model-driven application development. I've already started to evaluate few tools (For example http://www.arcstyler.com), but in order to get wider perspective, I'd like to know about as many tools as possible.Unfortunately there seems to be only ...

HiI am preparing for a certification exam. I have doubt about this question. Please help me. Please let me know the correct answer=======================================================================1. Part of an application's business logic is implemented using a limited setof connections ...

hello everybodywhat are the difference between the FactoryMethod and abstract_factory ?

I have a servlet to process the login request. The user name and password are passed to one MessageDrivenBean from the servlet. And from onMessage() method in the MessageDrivenBean I call Login CMP bean to verify the login information. If Login information exists in the database, return true, ...

I am use JMS inside one MessageDrivenBean. When I compile it and get the error message I did not understand why it happened. Here is code:public class LogBean implements MessageDrivenBean, MessageListener {protected MessageDrivenContext ctx;protected int match = 0;protected Context ...

i use JBuilder7 to develop a JSP and Servlet.when i make the files ,the system say "Can not find F;\bea\weblogic700\server\lib\weblogic_sp.jar to copy to WebApp MyWebApp : file is defined as element of library weblogic6.X Deploy"when i config Tool->Config servers ,i delete the ...