Simple Hello example for JBOSS

[Arijit Ghosh]

I have written a simple remote interface, home interface, the bean class, the deployment descriptor and the vendoe specific xml file (all manually) to test a simple Hello World case.
Now I have created the HelloWorld.jar file with the files in its proper folders --
i.e. I kept
Hello.class (Remote interface)
HelloHome.class (Home interface)
HelloBean.class (Bean class)
within a folder called "examples" while I kept
ejb-jar.xml (Deployment descriptor)
jboss.xml (Vendor specific file)
within a folder called "META-INF"
I successfully deployed the jar file (created by jar cf HelloWorld.jar *) into the deployment directory of JBOSS.
I now have the HelloClient file.
Few points to take not of --
I am working from the folder "samples" and I have three folders "src", "examples" and "META-INF" as the sub-folders. I am using "package examples" in all the java files which are placed in the "src" folder. I have compiled the files using "java -d examples src\*.java" This resulted in the generation of the corresponding 4 class files in the "examples" folder.
Now the main file is when I am trying to execute the Client file.
I am trying to execute the following command from the "samples" folder ---
"java examples.HelloClient"
This is giving the following errors --

C:\JBoss-2.4.3_Tomcat-3.2.3\samples>java examples.HelloClient
Exception in thread "main" javax.naming.NoInitialContextException: Need to speci
fy class name in environment or system property, or as an applet parameter, or i
n an application resource file: java.naming.factory.initial
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:6
40)
at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:243
)
at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.jav
a:280)
at javax.naming.InitialContext.lookup(InitialContext.java:347)
at examples.HelloClient.main(HelloClient.java:36)
I am listing the full codes for the 4 java files ---
Hello.java

package examples;
public interface Hello extends javax.ejb.EJBObject
{
  public String hello() throws java.rmi.RemoteException;
}

HelloHome.java

package examples;
public interface HelloHome extends javax.ejb.EJBHome
{
Hello create() throws java.rmi.RemoteException,
        javax.ejb.CreateException;
}

HelloBean.java

package examples;
import javax.ejb.SessionContext;
public class HelloBean implements javax.ejb.SessionBean
{
    public void ejbCreate()
    {
        System.out.println("ejbCreate()");
    }
    public void ejbRemove()
    {
        System.out.println("ejbRemove()");
    }
    public void ejbActivate()
    {
        System.out.println("ejbActivate()");
    }
    public void ejbPassivate()
    {
        System.out.println("ejbPassivate()");
    }
    public void setSessionContext(SessionContext ctx)
    {
        System.out.println("setSessionContext()");
    }
    public String hello()
    {
        System.out.println("hello()");
        return "Hello, World!";
    }
}

HelloClient.java

package examples;
import javax.naming.Context;
import javax.naming.InitialContext;
import java.util.Properties;
public class HelloClient {
public static void main(String[] args) throws Exception {
  Properties props = System.getProperties();
  Context ctx = new InitialContext(props);
  Object obj = ctx.lookup("HelloHome");
  HelloHome home = (HelloHome)
  javax.rmi.PortableRemoteObject.narrow(
obj, HelloHome.class);
  Hello hello = home.create();
  System.out.println(hello.hello());
  hello.remove();
 }
}

Above 4 files are part from Ed Roman's book.

jboss.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE jboss PUBLIC "-//JBoss//DTD JBOSS//EN" "http://www.jboss.org/j2ee/dtd/jboss.dtd">
<jboss>
   <enterprise-beans>
      <session>
         <ejb-name>Hello</ejb-name>
         <jndi-name>HelloHome</jndi-name>
      </session>
   </enterprise-beans>
</jboss>

ejb-jar.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE jboss PUBLIC "-//JBoss//DTD JBOSS//EN" "http://www.jboss.org/j2ee/dtd/jboss.dtd">

<ejb-jar>
 <enterprise-beans>
  <session>
   <ejb-name>Hello</ejb-name>
   <home>examples.HelloHome</home>
   <remote>examples.Hello</remote>
   <ejb-class>examples.HelloBean</ejb-class>
   <session-type>Stateless</session-type>
   <transaction-type>Container</transaction-type>
  </session>
 </enterprise-beans>
</ejb-jar>

CAN ANYONE PLEASE HELP ME ??

[ May 28, 2002: Message edited by: Arijit Ghosh ]

[jon boydell]

I think that the client can't find the directory on the jboss server to lookup the ejb. It needs to specify the url of the server and the factory to create an initial context.
Have you set up a jndi.properties file? Create one and put it in your classpath. Put the following in it:
java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
java.naming.provider.url=localhost:1099
java.naming.factory.url.pkgs=org.jboss.naming rg.jnp.interfaces
[ May 28, 2002: Message edited by: jon boydell ]

[Arijit Ghosh]

Hello Jon,
Thanks for the reply. Just one clarification...
Does this mean the steps that I had listed in the problem are correct i.e. Am I doing
the steps correctly?
There is one jndi.properties file in the default conf folder. I have edited that and
included all that you have mentioned.
I tried to execute it again but the same error is shown. Is it because of the classpath
?
Do I have to set the classpath to "DEFAULT" folder in my Autoexec.bat file ?
Thanks in advance.

[Arijit Ghosh]

C:\JBoss-2.4.3_Tomcat-3.2.3\samples>java examples.HelloClient
Exception in thread "main" javax.naming.NoInitialContextException: Cannot instan
tiate class: org.jnp.interfaces.NamingContextFactory. Root exception is java.la
ng.ClassNotFoundException: org.jnp.interfaces.NamingContextFactory
at java.net.URLClassLoader$1.run(URLClassLoader.java:198)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:186)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:265)
at java.lang.ClassLoader.loadClass(ClassLoader.java:262)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:322)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:207)
at com.sun.naming.internal.VersionHelper12.loadClass(VersionHelper12.jav
a:42)
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:6
49)
at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:243
)
at javax.naming.InitialContext.init(InitialContext.java:219)
at javax.naming.InitialContext.<init>(InitialContext.java:195)
at examples.HelloClient.main(HelloClient.java:30)
When I added the following to my classpath above errors occured.
"set CLASSPATH=%CLASSPATH%;C:\JBoss-2.4.3_Tomcat-3.2.3\jboss\conf\default"
I already have the following classpath set --
"set CLASSPATH=%CLASSPATH%;C:\JBoss-2.4.3_Tomcat-3.2.3\samples\examples"
All Hello example class files are stored in the directory "examples"
And as I have mentioned before I am executing "java examples.HelloClient" from the "samples" folder.
Please help !

[Arijit Ghosh]

Thanks Jon!
Got the problem... I had not included the jboss-client and jnp-client jar files in my classpath :roll: :roll:

[jawwad ahmed]

if u are using jboss3.0+ go to
C:\jboss3\cong\defualt\jndi.properties uncomment the lines.
Then copy that file to the client folder.
Jawwad Ahmed
SCJP
SCWCD
[e-mail]

[Arijit Ghosh]

Hi,
If I have downloaded JBOSS 2.4.4 or 2.4.5 i.e. 2.4.x version, and have also downloaded Tomcat 4.x version separately, how can I integrate them together ?
Is it by editing the MLET code in jboss.conf file ?