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How to set up EJB 3.0 client with annotation?

I am trying to call EJB but my simple program can't find a ejb

within netbeans. I also download a stub file from the admin page and add to the ejb client path. but still without the luck

@EJB

private static ConverterBean converterBean;

public static void main(String[] args) {

// TODO code application logic here

BigDecimal param = new BigDecimal ("100.00");

BigDecimal amount = converterBean.dollarToYen(param);

System.out.println( amount );

}

[506 byte] By [skoizumi2133a] at [2007-10-3 11:27:41]

«« Fastest way and Efficientiest way to find the Date withtin the Date Array
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# 1

I am actually following the sample chapter from this link http://java.sun.com/javaee/5/docs/tutorial/doc/EJB2.html

skoizumi2133a at 2007-7-15 13:53:49 >

top of Java-index,Enterprise & Remote Computing,Enterprise Technologies...

# 2

@EJB

private static ConverterBean converterBean;

If ConverterBean is your remote business interface, it will work. But from the name, it seems like a bean implementation class, which won't work.

From NetBeans' convention, maybe it should be:

@EJB

private static ConverterRemote converterBean;

cheng-fanga at 2007-7-15 13:53:49 >

# 3

I tried with remove one still doesn't work.

skoizumi2133a at 2007-7-15 13:53:49 >

# 4

Hi everybody.

I am facing a problem related to this.

Is there any restriction in using annotation to invocate an EJB. My scenario has the invoker in a package, and the target EJB in a different package, but both of them located at the same machine.

Thanks in advance for your attention.

Sergio G.

sgutierba at 2007-7-15 13:53:49 >

# 5

There is no restriction on which java package either the business interface or the client has.

For Remote EJB access from a java client, the @EJB annotation can only be used on the main

class of an Application Client component.In addition, when using @EJB on a field, the field

must be marked static.

If you're having trouble getting this to work, please post as much detailed information as possible

about exactly what error you're seeing and the related code/descriptors.

--ken

ksaksa at 2007-7-15 13:53:49 >

# 6

Hi ksaks.

This is my situation.

1. I have a normal class in package A. When I use the Netbeans wizard to call an Enterprise bean located at package B, it creates a method which issues a JNDI lookup and returns the interface for the Bean. When I use this method to initialize a field, I get a NullPointerException.

2. I have a JAXWS Web Service (Stateless) in package B. When I use the wizard, it defines a field annotated with EJB, and it allows me to call methods from the Bean without problems.

3. Using the list-jndi-entries command in asadmin, is not consistent the appearance of the interfaces of the EJB.

Thanks in advance for any help.

Kind Regards.

Sergio G.

sgutierba at 2007-7-15 13:53:49 >

# 7

Hi Sergio,Without seeing the actual code generated by the IDE it's difficult to debug. Please post theapplicable code snippets, as well as the full NullPointerException stack trace. --ken

ksaksa at 2007-7-15 13:53:49 >

# 8

Hi Ken.

First, I apologize for the long post.

I will ommit the specifics of methods within bean and client class.

It is something like:

/** The bean */

package co.com.une.medium.utils;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.SQLException;

import javax.annotation.PostConstruct;

import javax.annotation.PreDestroy;

import javax.annotation.Resource;

import javax.ejb.Stateless;

import javax.sql.DataSource;

/**

* @author saguti

@Stateless(mappedName="ejb/LoggerBean")

public class LoggerBean implements LoggerLocal

{

/** DataSource que provee las conexiones a la base de datos de Log */

@Resource(name="jdbc/Medium")

private DataSource bdFuente;

// Several non-static resources follow

/** Creates a new instance of LoggerBD2 */

public LoggerBean()

{

System.out.print("Constructor del EJB Logger");

}

// this callback method initializes the connection field

@PostConstruct

private void inicializar()

{

System.out.println("En postconstruct del EJB");

try

{

this.conexion = this.bdFuente.getConnection();

}

catch (Exception e)

{

e.printStackTrace();

}

// This is one of the methods exposed through the interface

// It receives the arguments and inserts into a database which is accesed through

// the connection field

public String registrarError(String ubicacionError, String transaccion, String idMensaje, String textoError)

{

....

}

// This other of the methods exposed through the interface

// It receives the arguments and inserts into a database which is accesed through

// the connection field

public String registrarRecepcion(String plataforma, String transaccion, String idMensaje, String mensaje)

{

....

}

// Callback annotated method to close the connection when database

@PreDestroy

private void finalizarLogger()

{

System.out.println("Invocado el predestroy del EJB");

try

{

conexion.close();

}

catch (SQLException ex)

{

System.out.println("LoggerBD:finalizarLogger:123:Error insertando a la base de datos de registro: " + ex.getMessage());

}

// A third method (dummy method) to test the reachability to the EJB)

public String chequear()

{

System.out.println("Chequear del EJB");

return "Aca estoy";

}

/** End of the bean code */

/** Remote interface of the bean */

package co.com.une.medium.utils;

import javax.ejb.Remote;

/**

* This is the business interface for Logger enterprise bean.

@Remote

public interface LoggerLocal

{

java.lang.String registrarError(String ubicacionError, String transaccion, String idMensaje, String textoError);

java.lang.String chequear();

java.lang.String registrarRecepcion(String plataforma, String transaccion, String idMensaje, String mensaje);

}

/** End of the interface code */

/** Beginning of the class code, located at other ejb-module. This is where when using the wizard it creates a private method which performs a JNDI Lookup */

// Note that this class is at another package

package co.com.une.medium.utilidades;

import co.com.une.medium.utils.LoggerLocal;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.ejb.EJB;

import javax.jms.Session;

import javax.jms.TextMessage;

import javax.jms.Topic;

import javax.jms.TopicConnection;

import javax.jms.TopicConnectionFactory;

import javax.jms.TopicPublisher;

import javax.jms.TopicSession;

import javax.naming.Context;

import javax.naming.InitialContext;

import javax.naming.NamingException;

/**

* Clase utilitaria que genera un mensaje JMS y lo despacha en una cola

* @author sgutierb

* @version 1.0

public class ClienteJMS

{

// Several fields which are particular to this class

/** Contexto de acceso al servicio de nombre JNDI */

private Context contextoJndi=null;

.....

/* Here I guess that:

1. I should annotate the field or...

2. Not to use the annotation and use the method below

// I have tried the two ways. When using just the annotation, I got the

// NullPointerException. When using the method,

// I got the NamingLookupException

@EJB

private LoggerLocal loggerBean;

/** Constructor por defecto para el Cliente JMS */

public ClienteJMS()

{

}

public ClienteJMS(String nombre, String transaccion, String idMensaje, String texto)

{

this.textoMensaje = texto;

this.nombrePlataforma = nombre;

this.nombreTransaccion = transaccion;

this.idMensaje = idMensaje;

//this.interfaceLogger = this.lookupLoggerBD2();

try

{

// Code of the class

...

// Here I use the method

this.loggerBean = this.lookupLoggerBean();

}

catch (Exception ex)

{

// More code of the class

}

public boolean publicarMensaje()

{

boolean valorRetorno = false;

try

{

......

try

{

....

}

catch(Exception ex)

{

ex.printStackTrace();

}

catch (Exception ex)

{

...

}

finally

{

....

}

public boolean getEstadoCliente()

{

...

}

// This is the method which is created by the wizard

// When I use this to assign the field, I get a NamingLookupException

private LoggerLocal lookupLoggerBean()

{

try {

Context c = new InitialContext();

return (LoggerLocal) c.lookup("java:comp/env/ejb/LoggerBean");

}

catch(NamingException ne) {

Logger.getLogger(getClass().getName()).log(Level.SEVERE,"exception caught" ,ne);

throw new RuntimeException(ne);

}

/** End of the client class */

/ ** This is the text of the NullPointerException */

// The referred line at the class corresponds to a calling to a method of the bean */

tpWorkerThread-8080-0;_RequestID=f82063a4-06d0-4839-80b3-1167e034715e;|

java.lang.NullPointerException

at co.com.une.medium.utilidades.ClienteJMS.publicarMensaje(ClienteJMS.java:165)

at co.com.une.medium.externo.InvocadorImpl.invocacionAsincronica(InvocadorImpl.java:60)

at co.com.une.medium.externo.InvocadorMedium.cambiarEstado(InvocadorMedium.java:60)

at co.com.une.medium.externo.Medium.cambiarServicio(Medium.java:290)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:585)

at com.sun.enterprise.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1050)

at com.sun.enterprise.security.SecurityUtil.invoke(SecurityUtil.java:165)

at com.sun.ejb.containers.BaseContainer.invokeTargetBeanMethod(BaseContainer.java:2766)

at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:3847)

at com.sun.ejb.containers.WebServiceInvocationHandler.invoke(WebServiceInvocationHandler.java:147)

at $Proxy245.cambiarServicio(Unknown Source)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:585)

at com.sun.xml.ws.server.PeptTie._invoke(PeptTie.java:61)

at com.sun.xml.ws.protocol.soap.server.SOAPMessageDispatcher.invokeEndpoint(SOAPMessageDispatcher.java:280)

at com.sun.xml.ws.protocol.soap.server.SOAPMessageDispatcher$SoapInvoker.invoke(SOAPMessageDispatcher.java:588)

at com.sun.xml.ws.protocol.soap.server.SOAPMessageDispatcher.receive(SOAPMessageDispatcher.java:147)

at com.sun.xml.ws.server.Tie.handle(Tie.java:90)

at com.sun.enterprise.webservice.Ejb3MessageDispatcher.handlePost(Ejb3MessageDispatcher.java:160)

at com.sun.enterprise.webservice.Ejb3MessageDispatcher.invoke(Ejb3MessageDispatcher.java:89)

at com.sun.enterprise.webservice.EjbWebServiceServlet.dispatchToEjbEndpoint(EjbWebServiceServlet.java:186)

at com.sun.enterprise.webservice.EjbWebServiceServlet.service(EjbWebServiceServlet.java:117)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)

at com.sun.enterprise.web.AdHocContextValve.invoke(AdHocContextValve.java:101)

at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)

at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:71)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:182)

at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)

at com.sun.enterprise.web.VirtualServerPipeline.invoke(VirtualServerPipeline.java:120)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:137)

at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)

at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:239)

at com.sun.enterprise.web.connector.grizzly.ProcessorTask.invokeAdapter(ProcessorTask.java:667)

at com.sun.enterprise.web.connector.grizzly.ProcessorTask.processNonBlocked(ProcessorTask.java:574)

at com.sun.enterprise.web.connector.grizzly.ProcessorTask.process(ProcessorTask.java:844)

at com.sun.enterprise.web.connector.grizzly.ReadTask.executeProcessorTask(ReadTask.java:287)

at com.sun.enterprise.web.connector.grizzly.ReadTask.doTask(ReadTask.java:212)

at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:252)

at com.sun.enterprise.web.connector.grizzly.WorkerThread.run(WorkerThread.java:75)

|#]

/** End of the NullPointerException */

/** Begin of the NamingLookupException. It occurs when using the lookup method */

e=httpWorkerThread-8080-1;_RequestID=17f2997a-44af-4ce7-a9a5-b472dddcacfc;|exception caught

javax.naming.NameNotFoundException: No object bound to name java:comp/env/ejb/LoggerBean

at com.sun.enterprise.naming.NamingManagerImpl.lookup(NamingManagerImpl.java:751)

at com.sun.enterprise.naming.java.javaURLContext.lookup(javaURLContext.java:156)

at com.sun.enterprise.naming.SerialContext.lookup(SerialContext.java:307)

at javax.naming.InitialContext.lookup(InitialContext.java:351)

at co.com.une.medium.utilidades.ClienteJMS.lookupLoggerBean(ClienteJMS.java:206)

at co.com.une.medium.utilidades.ClienteJMS.<init>(ClienteJMS.java:116)

at co.com.une.medium.externo.InvocadorImpl.invocacionAsincronica(InvocadorImpl.java:53)

at co.com.une.medium.externo.InvocadorMedium.cambiarEstado(InvocadorMedium.java:60)

at co.com.une.medium.externo.Medium.cambiarServicio(Medium.java:290)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:585)

at com.sun.enterprise.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1050)

at com.sun.enterprise.security.SecurityUtil.invoke(SecurityUtil.java:165)

at com.sun.ejb.containers.BaseContainer.invokeTargetBeanMethod(BaseContainer.java:2766)

at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:3847)

at com.sun.ejb.containers.WebServiceInvocationHandler.invoke(WebServiceInvocationHandler.java:147)

at $Proxy268.cambiarServicio(Unknown Source)