Accessing EJB from a Swing Client

[Torsten Oppermann]

Hello ! I have trouble figuring out how to access an EJB from a remote Swing/SE Client running on a different machine. I tried the example in the official tutorial, but its somewhat unclear.

I assume, that i need the Business Interface of the EJB on the client side as well ?

A little example would be awesome

Thank you

[kurt hanni]

Yes you need the remote business interface on the client side.

put "gf-client.jar" in your classpath, then access the bean using JNDI lookup.

[kurt hanni]

Client App

Remote interface

package com.sample.bean;

@Remote
public interface TestRemote {
	public void test();
}

then access the bean using JNDI lookup

import javax.naming.InitialContext;
import javax.naming.NamingException;

import com.sample.bean.TestRemote;

public class ClientMain {

	TestRemote bean;
	
	public static void main(String[] args) {
		ClientMain client = new ClientMain();
		client.lookup();
		System.out.println("*** Calling from ClienMain");
		client.bean.test();
	}
	
	private void lookup() {
		try {
			InitialContext context = new InitialContext();
			bean = (TestRemote) context.lookup("java:global/ejb-app/TestRemoteBean");		
			
		} catch (NamingException e) {
			e.printStackTrace();
		}

	}

}

Remote interface and bean implementation class should be in "ejb-app" application.

remember put gf-client.jar in your client-app classpath (im using glassfish server for my ejb-app)

[Torsten Oppermann]

Thank you very much, that was exactly what i was looking for.

So this can be very server specific ? or is it always some kind of Jar, like for JBoss ?

I also use Glassfish, but im curious

[kurt hanni]

other containers have corresponding client.jar, like for jboss you use the jbossall-client.jar in client applications for JNDI lookups

[Torsten Oppermann]

ok great, thank you very much !

[Torsten Oppermann]

i tried your example, slightly modified today and ran into some problems. Here is what i did:

on the glassfish server is deployed:

package oppermann.hellobean;

import javax.ejb.Remote;

/**
 *
 * @author torsten
 */
@Remote
public interface HelloWorld {
    public void helloWorld();
}

and

package oppermann.hellobean;

import javax.ejb.Stateless;

/**
 *
 * @author torsten
 */
@Stateless
public class HelloWorldImpl 
    implements HelloWorld {

    @Override
    public void helloWorld() {
        System.out.println("Hello World from EJB");
    }
    
}

on the client side with gf-client.jar and javaee-api-6.0.jar as additional libraries:

package oppermann.hellobean;

import javax.ejb.Remote;

/**
 *
 * @author torsten
 */
@Remote
public interface HelloWorld {
    public void helloWorld();
}

and finally the client:

package helloworldclient;

import javax.naming.InitialContext;
import javax.naming.NamingException;
import oppermann.hellobean.HelloWorld;

/**
 *
 * @author torsten
 */
public class Client {

    HelloWorld bean;  
      
    public static void main(String[] args) {  
        Client client = new Client();  
        client.lookup();  
        System.out.println("*** Calling from Client");  
        client.bean.helloWorld();  
    }  
      
    private void lookup() {  
        try {  
            InitialContext context = new InitialContext();  
            bean = (HelloWorld) 
                    context.lookup("java:global/ejb-app/HelloWorldImpl");         
              
        } catch (NamingException e) {  
            e.printStackTrace();  
        }  
  
    }  
}

any ideas ? here the errors i get:

05.07.2011 10:53:50 com.sun.enterprise.v3.server.CommonClassLoaderServiceImpl findDerbyClient
INFO: Cannot find javadb client jar file, derby jdbc driver will not be available by default.
05.07.2011 10:53:53 com.sun.enterprise.iiop.security.SecurityMechanismSelector postConstruct
SCHWERWIEGEND: IIOP1005: An exception has occured in the ejb security initialization.
org.jvnet.hk2.component.ComponentException: injection failed on org.glassfish.api.invocation.InvocationManagerImpl.invHandlers with class [Lorg.glassfish.api.invocation.ComponentInvocationHandler;
	at org.jvnet.hk2.component.InjectionManager.error_injectionException(InjectionManager.java:277)
	at org.jvnet.hk2.component.InjectionManager.inject(InjectionManager.java:159)
	at org.jvnet.hk2.component.InjectionManager.inject(InjectionManager.java:91)
	at com.sun.hk2.component.AbstractCreatorImpl.inject(AbstractCreatorImpl.java:126)
	at com.sun.hk2.component.ConstructorCreator.initialize(ConstructorCreator.java:91)
	at com.sun.hk2.component.AbstractCreatorImpl.get(AbstractCreatorImpl.java:82)
	at com.sun.hk2.component.SingletonInhabitant.get(SingletonInhabitant.java:67)
	at com.sun.hk2.component.EventPublishingInhabitant.get(EventPublishingInhabitant.java:139)
	at com.sun.hk2.component.AbstractInhabitantImpl.get(AbstractInhabitantImpl.java:76)
	at org.jvnet.hk2.component.Habitat.getByContract(Habitat.java:1042)
	at org.jvnet.hk2.component.Habitat.getComponent(Habitat.java:777)
	at com.sun.enterprise.iiop.security.SecurityMechanismSelector.postConstruct(SecurityMechanismSelector.java:166)
	at com.sun.hk2.component.AbstractCreatorImpl.inject(AbstractCreatorImpl.java:131)
	at com.sun.hk2.component.ConstructorCreator.initialize(ConstructorCreator.java:91)
	at com.sun.hk2.component.AbstractCreatorImpl.get(AbstractCreatorImpl.java:82)
	at com.sun.hk2.component.SingletonInhabitant.get(SingletonInhabitant.java:67)
	at com.sun.hk2.component.EventPublishingInhabitant.get(EventPublishingInhabitant.java:139)
	at com.sun.hk2.component.AbstractInhabitantImpl.get(AbstractInhabitantImpl.java:76)
	at org.jvnet.hk2.component.Habitat.getBy(Habitat.java:1048)
	at org.jvnet.hk2.component.Habitat.getByType(Habitat.java:1029)
	at com.sun.hk2.component.InjectInjectionResolver.getComponentInjectValue(InjectInjectionResolver.java:159)
	at com.sun.hk2.component.InjectInjectionResolver.getValue(InjectInjectionResolver.java:90)
	at org.jvnet.hk2.component.InjectionManager.inject(InjectionManager.java:141)
	at org.jvnet.hk2.component.InjectionManager.inject(InjectionManager.java:91)
	at com.sun.hk2.component.AbstractCreatorImpl.inject(AbstractCreatorImpl.java:126)
	at com.sun.hk2.component.ConstructorCreator.initialize(ConstructorCreator.java:91)
	at com.sun.hk2.component.AbstractCreatorImpl.get(AbstractCreatorImpl.java:82)
	at com.sun.hk2.component.SingletonInhabitant.get(SingletonInhabitant.java:67)
	at com.sun.hk2.component.EventPublishingInhabitant.get(EventPublishingInhabitant.java:139)
	at com.sun.hk2.component.AbstractInhabitantImpl.get(AbstractInhabitantImpl.java:76)
	at org.jvnet.hk2.component.Habitat.getBy(Habitat.java:1048)
	at org.jvnet.hk2.component.Habitat.getByType(Habitat.java:1029)
	at org.jvnet.hk2.component.Habitat.getComponent(Habitat.java:779)
	at com.sun.enterprise.iiop.security.Lookups._getSecurityContextUtil(Lookups.java:97)
	at com.sun.enterprise.iiop.security.Lookups.getSecurityContextUtil(Lookups.java:92)
	at com.sun.enterprise.iiop.security.SecClientRequestInterceptor.<init>(SecClientRequestInterceptor.java:119)
	at com.sun.enterprise.security.appclient.AppclientIIOPInterceptorFactory.getClientInterceptorInstance(AppclientIIOPInterceptorFactory.java:127)
	at com.sun.enterprise.security.appclient.AppclientIIOPInterceptorFactory.createClientRequestInterceptor(AppclientIIOPInterceptorFactory.java:96)
	at org.glassfish.enterprise.iiop.impl.GlassFishORBInitializer.post_init(GlassFishORBInitializer.java:132)
	at com.sun.corba.ee.impl.interceptors.PIHandlerImpl.postInitORBInitializers(PIHandlerImpl.java:915)
	at com.sun.corba.ee.impl.interceptors.PIHandlerImpl.initialize(PIHandlerImpl.java:265)
	at com.sun.corba.ee.impl.orb.ORBImpl.postInit(ORBImpl.java:643)
	at com.sun.corba.ee.impl.orb.ORBImpl.set_parameters(ORBImpl.java:704)
	at com.sun.corba.ee.impl.orb.ORBImpl.setParameters(ORBImpl.java:691)
	at com.sun.corba.ee.spi.osgi.ORBFactory.initialize(ORBFactory.java:107)
	at org.glassfish.enterprise.iiop.impl.GlassFishORBManager.initORB(GlassFishORBManager.java:581)
	at org.glassfish.enterprise.iiop.impl.GlassFishORBManager.getORB(GlassFishORBManager.java:263)
	at org.glassfish.enterprise.iiop.impl.GlassFishORBFactoryImpl.createORB(GlassFishORBFactoryImpl.java:93)
	at org.glassfish.enterprise.iiop.api.GlassFishORBHelper.getORB(GlassFishORBHelper.java:120)
	at com.sun.enterprise.naming.impl.SerialContext.getORB(SerialContext.java:365)
	at com.sun.enterprise.naming.impl.SerialContext.getProviderCacheKey(SerialContext.java:372)
	at com.sun.enterprise.naming.impl.SerialContext.getRemoteProvider(SerialContext.java:402)
	at com.sun.enterprise.naming.impl.SerialContext.getProvider(SerialContext.java:347)
	at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:504)
	at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:455)
	at javax.naming.InitialContext.lookup(InitialContext.java:392)
	at helloworldclient.Client.lookup(Client.java:29)
	at helloworldclient.Client.main(Client.java:21)
Caused by: org.jvnet.hk2.component.ComponentException: Failed to create class com.sun.enterprise.resource.pool.PoolManagerImpl
	at com.sun.hk2.component.ConstructorCreator.create(ConstructorCreator.java:71)
	at com.sun.hk2.component.AbstractCreatorImpl.get(AbstractCreatorImpl.java:80)
	at com.sun.hk2.component.SingletonInhabitant.get(SingletonInhabitant.java:67)
	at com.sun.hk2.component.EventPublishingInhabitant.get(EventPublishingInhabitant.java:139)
	at com.sun.hk2.component.AbstractInhabitantImpl.get(AbstractInhabitantImpl.java:76)
	at org.jvnet.hk2.component.Habitat$5.get(Habitat.java:701)
	at java.util.AbstractList$Itr.next(AbstractList.java:345)
	at java.util.AbstractCollection.toArray(AbstractCollection.java:171)
	at com.sun.hk2.component.InjectInjectionResolver.getArrayInjectValue(InjectInjectionResolver.java:113)
	at com.sun.hk2.component.InjectInjectionResolver.getValue(InjectInjectionResolver.java:81)
	at org.jvnet.hk2.component.InjectionManager.inject(InjectionManager.java:141)
	... 56 more
Caused by: java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/resource/ResourceException
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
	at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
	at java.lang.Class.getDeclaredConstructors0(Native Method)
	at java.lang.Class.privateGetDeclaredConstructors(Class.java:2389)
	at java.lang.Class.getConstructor0(Class.java:2699)
	at java.lang.Class.newInstance0(Class.java:326)
	at java.lang.Class.newInstance(Class.java:308)
	at com.sun.hk2.component.ConstructorCreator.create(ConstructorCreator.java:65)
	... 66 more
javax.naming.NamingException: Lookup failed for 'java:global/ejb-app/HelloWorldImpl' in SerialContext[myEnv={java.naming.factory.initial=com.sun.enterprise.naming.impl.SerialInitContextFactory, java.naming.factory.url.pkgs=com.sun.enterprise.naming, java.naming.factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl} [Root exception is javax.naming.NameNotFoundException: ejb-app]
	at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:518)
	at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:455)
	at javax.naming.InitialContext.lookup(InitialContext.java:392)
	at helloworldclient.Client.lookup(Client.java:29)
	at helloworldclient.Client.main(Client.java:21)
Caused by: javax.naming.NameNotFoundException: ejb-app
	at com.sun.enterprise.naming.impl.TransientContext.resolveContext(TransientContext.java:310)
	at com.sun.enterprise.naming.impl.TransientContext.lookup(TransientContext.java:218)
	at com.sun.enterprise.naming.impl.TransientContext.lookup(TransientContext.java:219)
	at com.sun.enterprise.naming.impl.SerialContextProviderImpl.lookup(SerialContextProviderImpl.java:77)
	at com.sun.enterprise.naming.impl.RemoteSerialContextProviderImpl.lookup(RemoteSerialContextProviderImpl.java:94)
	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:597)
	at com.sun.corba.ee.impl.presentation.rmi.ReflectiveTie.dispatchToMethod(ReflectiveTie.java:144)
	at com.sun.corba.ee.impl.presentation.rmi.ReflectiveTie._invoke(ReflectiveTie.java:174)
	at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatchToServant(CorbaServerRequestDispatcherImpl.java:528)
	at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatch(CorbaServerRequestDispatcherImpl.java:199)
	at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequestRequest(CorbaMessageMediatorImpl.java:1624)
	at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(CorbaMessageMediatorImpl.java:1486)
	at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleInput(CorbaMessageMediatorImpl.java:990)
	at com.sun.corba.ee.impl.protocol.giopmsgheaders.RequestMessage_1_2.callback(RequestMessage_1_2.java:214)
	at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(CorbaMessageMediatorImpl.java:742)
	at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.dispatch(CorbaMessageMediatorImpl.java:539)
	at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.doWork(CorbaMessageMediatorImpl.java:2324)
	at com.sun.corba.ee.impl.orbutil.threadpool.ThreadPoolImpl$WorkerThread.performWork(ThreadPoolImpl.java:497)
	at com.sun.corba.ee.impl.orbutil.threadpool.ThreadPoolImpl$WorkerThread.run(ThreadPoolImpl.java:540)
*** Calling from Client
Exception in thread "main" java.lang.NullPointerException
	at helloworldclient.Client.main(Client.java:23)
Java Result: 1