Nabble - EJB General

PROBLEM START WEBSPHERE 6.1

2008-11-30T05:12:03Z

Hello,

I have a problem when I try star the websphere 6.1 Server. I get the next error:

Could you help me? Thanks

ejb constructor??

2008-11-30T01:48:17Z

Hi,
i'm new in j2ee.. So i made a stateless session bean, my ejb skeleton is:
i hava a query.jsp page, which request a query (string), after that the ejb Bean connect an Oracle database,
the ejb ha a rank function which ranking the resultset, after that i show the result a result jsp page. this works:)
but, i would give some choice for the users to the query.jsp, for what column would they look like, to the result.jsp.
So i think my bean should look like:

constructor (String query){connect to database..;
rank();
}
get() methods..

destructor (){disconnect;}

So i know i don't know the ejb concepts to much so i ask some idea, how i should realize what i would like.
I haven't find how possible write a constructor for a bean class, and how can call it. For example my result.jsp : i don't know where the c

QueryRemote queryr = null;
public void jspInit() {
try {
InitialContext ic = new InitialContext();
queryr = (QueryRemote) ic.lookup("query/QueryBean/remote");
..}

So my question is there any option, to call a constructor with an argument?
Or what do you advice for my problem? I 've interested any idea..

Thanks in advance..

jta in EJB

2008-11-17T02:42:29Z

Hello everybody.
I wanted to ask a question. I am establishing a session bean with JTA that reads messages from a queue. TRANSACTIONS am creating the type of bean, but it does not make the rollback me when I return the message to the queue. Can anyone tell me a link to any page or some such.
Thank you

How to modify the pool of ejb with JMX in Weblogic 10?

2008-10-14T01:28:21Z

Hello

I put this message to see if anyone can help me. I want to know whether WebLogic 10 is you can modify the pool of ejb with JMX. That means that if you can change and do not have to be according to what you have set when compiling the ejb.
Thanks

EJB - Calling method2 from method1 of same EJB

2008-09-03T15:47:46Z

Is it possible by any combination of TRANSACTION attribute setup to make a internal call within the same EJB.

Can you provide the setup which would make this call possible?

If not possible, what is the only other way to make such calls?

Survey request

2008-06-20T07:57:30Z

Dear member,

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Note on data security: This survey is anonymous, so no personal information will be asked.

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Thank You!!!

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problem in ejb3 on jboss-4.2

2008-05-07T21:34:45Z

hi,
I am new to eb3 and i am having following problem when running stateful application, the stateless application works fine but stateful not...following is the issue...

I am having EJB 3 stateful application. Code is shown below

try {
Properties props = new Properties();
props.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
props.setProperty(Context.URL_PKG_PREFIXES, "org.jboss.namingrg.jnp.interfaces");
props.put(Context.PROVIDER_URL, "jnp://localhost:1099");
InitialContext ic = new InitialContext(props);
//InitialContext ic = new InitialContext();
System.out.println("JSP INIT Befor lookup=============");
//Object obj = (Object) ic.lookup("StatefulCode/AccountBean/remote");
account = (AccountRemote) ic.lookup("StatefulCode_1/AccountBean/remote");

//account = (AccountRemote)javax.rmi.PortableRemoteObject.narr ow(obj,AccountBean.class);

System.out.println("JSP INIT After lookup=============");
//System.out.println("JSP INIT After lookup test============="+obj.getClass().getName());
System.out.println("Loaded Account Bean");

} catch (Exception ex) {
ex.printStackTrace();
}

When I run the application, I am facing

java.lang.ClassCastException: $Proxy72
ERROR [STDERR] at org.apache.jsp.ejb3.WebClient_jsp.jspInit(WebClien t_jsp.java:28)
ERROR [STDERR] at org.apache.jasper.runtime.HttpJspBase.init(HttpJsp Base.java:51)
ERROR [STDERR] at org.apache.jasper.servlet.JspServletWrapper.getSer vlet(JspServletWrapper.java:158)

In JBoss, in Global JNDI Namespace it is showing

+- StatefulCode_1 (class: org.jnp.interfaces.NamingContext)
| +- AccountBean (class: org.jnp.interfaces.NamingContext)
| | +- remote (class: java.lang.Object)
| | +- remoteStatefulProxyFactory (proxy: $Proxy73 implements interface org.jboss.ejb3.ProxyFactory)

I was not able to solve. Can anyone suggest what can be the possible remedy for this ?

What to use instead of a singleton in EJB ?

2008-04-21T08:21:01Z

Hello,
what is the prefered way to manage data centrally?

If I wrote normal java software I used a singleton and within this singleton I used some locking.
So I was able to hold some data at a central threadsafe place.

Now I write an EJB application ... and I see that a 'singleton' is not allowed.

One solution might be to use a database that does only exist in memory.
But, is that the prefered way to realize a central data store?
I mean, this store is not very comlicated, doesn't need do be persistent and will not use all the great features of a database.
It should be a unique information resource for many other instances of some java classes.

An example can be a group of users and the singleton provides a structure to hold what user talks to another.
Another example may be a list of logged in users and a certain related ID or some things like that.

So what is the best way to implement such a thing, that in a JavaSE program a singleton would do?
Thanks

how to deal with a own propertyfile and EJB

2008-04-21T08:20:17Z

Hello,
I'm quite new to the EJB technology.
My problem is, how to handle a property file?

Let's say I have a custom 'property.xml' (that holds some application specific constants) somewhere in my EJB jar or in a related jar (so it is in the classapth).

Usually (not with EJB) I would write a class (let's name it 'Props', see below) which reads the property file once and initialize some public static members.

In an object (see below 'MyClass') I would then use 'Props.memberName' if I want to have access to a constant property.

class with public static constants members; read the file only once; properties are in memory ...
{code}public class Props
public static String FOO = null;
static
{
Properties props = new Properties();
try
{
props.loadFromXML(CConstants.class.getClass().getClassLoader().getResourceAsStream("propertyFile.xml"));
FOO = props.getProperty("FOO");
}
catch(Exception e){...}
}
}{code}

The class that uses the properties<br>
{code}public class MyClass
{
...
public void doSomething()
{
...
String s = Props.FOO + " BAR";
...
}
...
}{code}

But unfortunately static things are not allowed in EJB ...

What is the preferred way to get access to the properties?
To read the file each time an EJB is used, will cause much disc-I/O and xml parsing (this is very unefficient).
Is there no mechanism to read such things once only?

I would be very pleased to get an answer, because I don't know how to solve this problem
Thanks

Re: @Interceptor Annotation

2008-03-11T03:18:42Z

EJB 3.0 interceptors provide the bean developer with fine grained control over the method invocation flow. They can be used on stateless session beans, stateful session beans, and message driven beans. The interceptor may be either a method in the same bean class or an external class.

------------------
Software developer

@Interceptor Annotation

2008-01-10T01:05:53Z

Guys,

I'm pretty new to this forum. I've started recently to explore on EJB's. I would like to know what is the use of @Interceptor Annotation?

Thanks in advance!