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- Download and install OpenEJB
- Setup your development environment
- Write an EJB
- Write an EJB client
- Start the server
- Deploy the EJB
- Run the client
- Stop the server
1. Download and Install OpenEJB
Follow these instructions
2. Setup your development environment
Eclipse
- Open eclipse and create a new java project. Name it EJBProject
- Add the following jars to the build path of your project
- OPENEJB_HOME/lib/geronimo-ejb_3.0_spec-1.0.jar
- Now create another project named EJBClient. This is where we will write a test client
- Add the following jars to the build path of this project
- OPENEJB_HOME/lib/openejb-client-3.0.0-SNAPSHOT.jar
- Add the EJBProject to the classpath of the EJBClient project
3. Start the Server
Open the command prompt and run the following command:
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d:\openejb-3.0.0-SNAPSHOT\bin\openejb start
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You will get the following message on the console:
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D:\openejb-3.0.0-SNAPSHOT>bin\openejb start
Apache OpenEJB 3.0.0-SNAPSHOT build: 20070830-07:53
http://openejb.apache.org/
OpenEJB ready.
[OPENEJB:init] OpenEJB Remote Server
** Starting Services **
NAME IP PORT
httpejbd 0.0.0.0 4204
admin thread 0.0.0.0 4200
ejbd 0.0.0.0 4201
hsql 0.0.0.0 9001
telnet 0.0.0.0 4202
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Ready!
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4. Write an EJB
In the EJB project create a new interface named Greeting
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package com.myejbs;
import javax.ejb.Remote;
@Remote
public interface Greeting {
public String greet();
}
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Now create a new class named GreetingBean which implements the above interface (shown below)
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package com.myejbs;
import javax.ejb.Stateless;
@Stateless
public class GreetingBean implements Greeting {
public String greet() {
return "My First Remote Stateless Session Bean";
}
}
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5. Deploy the EJB
- Export the EJBProject as a jar file. Name it greeting.jar and put it in the OPENEJB_HOME/apps directory.
- Open the command prompt and type in the following command:
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d:\openejb-3.0.0-SNAPSHOT > bin\openejb deploy apps\greeting.jar
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This should give you the following output:
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D:\openejb-3.0.0-SNAPSHOT>bin\openejb deploy apps\greeting.jar
Application deployed successfully at \{0\}
App(id=D:\openejb-3.0.0-SNAPSHOT\apps\greeting.jar)
EjbJar(id=greeting.jar, path=D:\openejb-3.0.0-SNAPSHOT\apps\greeting.jar)
Ejb(ejb-name=GreetingBean, id=GreetingBean)
Jndi(name=GreetingBeanRemote)
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Notice the Jndi(name=GreetingBeanRemote) information. Keep this handy as this is the JNDI name of the bean which the client will use for lookup
6. Write the Client
In the EJBClient project, create a class named Client (shown below)
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package com.myclient;
import com.myejbs.Greeting;
import javax.naming.InitialContext;
import java.util.Properties;
public class Client {
public static void main(String[] args) {
try {
Properties p = new Properties();
p.put("java.naming.factory.initial", "org.openejb.client.RemoteInitialContextFactory");
p.put("java.naming.provider.url", "ejbd://127.0.0.1:4201");
InitialContext ctx = new InitialContext(p);
Greeting greeter = (Greeting) ctx.lookup("GreetingBeanRemote");
String message = greeter.greet();
System.out.println(message);
} catch (Exception e) {
e.printStackTrace();
}
}
}
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7. Run the Client
Open Client.java in eclipse and run it as a java application. You should see the following message in the console view:
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My First Remote Stateless Session Bean
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8. Stop the server
There are two ways to stop the server:
- You can press Ctrl+c on the command prompt to stop the server
- On the command prompt type in the following command:
No Format D:\openejb-3.0.0-SNAPSHOT>bin\openejb stop