Sun JDK 6.0+ (J2SE 1.6)
Eclipse IDE for Java EE Developers, which is platform specific
Apache Geronimo Eclipse Plugin 2.1.x
Apache Geronimo Server 2.1.x
Note
Geronimo version 2.1.x, Java 1.5 runtime, and Eclipse Ganymede are used is used in this tutorial but other versions can be used instead (e.g., Geronimo version 2.2, Java 1.6, Eclipse Europa)

Let us briefly understand this application. This application will take you through creating a simple Stateless Session EJB. Later we will develop a Java Application client to access this EJB. EJB development will make use of annotations which are introduced in Java EE5.

Setting up Eclipse IDE for EJB application development

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Launch Eclipse and select Window - -> Open Perspective --> Other --> JavaEE and select OK

Right-click under Project Explorer and create a new EJB project. Mention the fields as shown in the figure. For all the other windows give default values and select Finish.
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Under Project Explorer, Right-click on SimpleEJB and create a new package ejb. Mention the fields as shown in the figure. Select Finish.
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Right-click on SimpleEJB project under project explorer and select Properties.
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Select Java Build Path and select Add External JARs.
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Browse to the directory <GERONIMO_HOME>\repository\org\apache\geronimo\specs\geronimo-ejb_3.0_spec\1.0.1 and select geronimo-ejb_3.0_spec-1.0.1.jar.
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Once done select Ok. You can see the geronimo-ejb_3.0_spec-1.0.1.jar added to the build path. This jar provides the essential classes required for the EJB development.
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This completes the setting of Eclispe IDE for EJB application development.

Developing EJB

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local interface, EJB

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remote interface and Bean

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class

Right - click on the ejb package and create a new Remote interface Interface CountryCapital as shown in the figure:
Enter the fields as shown in the figure and select Finish.
Add the following code as shown below
Code Block
title CountryCapital.java
borderStyle solid
package ejb; import javax.ejb.Remote; @Remote public interface CountryCapital { public String capitalName(String countryName); }
Here @Remote is an annotation used to declare the interface as a Remote Interface.
Similarly create a Local interface CountryCapitalLocal. Add the following code to the interface.
Code Block
title CountryCapitalLocal.java
borderStyle solid
package ejb; import javax.ejb.Local; @Local public interface CountryCapitalLocal { public String capitalName(String countryName); }
Similarly in this code we have @Local annotation which declares this interface as local.

In remote the Remote as well as local the Local interface we have the declaration for only one Business method. So only this method will be visible to the application client. Methods other than capitalName, if implemented in the Bean class, will be private to the Bean class and will not be visible to application client.
Next The next step is to create a Bean Class class which will implement the Business method to be executed. Right - click on the jsf ejb package and create a new class.
Enter the class name as CountryCapitalBean.

Populate the bean class with the code as follows

Code Block

title	CountryCapitalBean.java
borderStyle	solid

package ejb;

import javax.ejb.Stateless;
@Stateless
public class CountryCapitalBean implements CountryCapital,CountryCapitalLocal{
	public String capitalName(String countryName)
	{
		String capital=new String("No such country");
		if (countryName.equalsIgnoreCase("India"))
		{
			capital="New Delhi";
		}
		if (countryName.equalsIgnoreCase("United States Of America"))
		{
			capital="Washington DC";
		}
		if (countryName.equalsIgnoreCase("China"))
		{
			capital="BejingBeijing";
		}

		return capital;

	}

}

This completes the development of EJB application.

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title	Warning

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.

...

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Developing a Java Client

Select File - -> New --> Project - -> Java -JavaEE -> Java Application Client Project. Select Next.
In the New Project Window give the Project name as ApplicationClient and select Next.
On the Java Settings window. Select the Projects tab and click Add.
Check the box for SimpleEJB and select OK.

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This will add the SimpleEJB project to the build path of the Application Client as shown in the figure. Select Finish.

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Tip

title	Why to did we add the EJB project to build path :(??

This is because the build path is used to find the classes referenced by your Application Client source code. These , and these classes will be required for compilation of Application Client source code.

Right - click on package appclient ApplicationClient project and create a new Java Class .
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as shown in the following figure:

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Give the package name as appclient and Give the class name as ApplicationClient as shown in the figure. Select Finish.
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Populate the ApplicationClient.java class with the following code:

Code Block

title	ApplicationClient.java
borderStyle	solid

package appclient;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Properties;
import ejb.CountryCapital;
import javax.naming.Context;
import javax.naming.InitialContext;

public class ApplicationClient {
	 public static void main(String [] args)
	 {
		 String capital=new String();
		 try{
			 Properties prop=new Properties();
			 prop.put(Context.INITIAL_CONTEXT_FACTORY, "org.apache.openejb.client.RemoteInitialContextFactory");
				prop.put("java.naming.provider.url", "ejbd://localhost:4201");
	 Context context = new InitialContext(prop);

	 CountryCapital myejb =
	 (CountryCapital)context.lookup("CountryCapitalBeanRemote");
	 System.out.println("Give the name of a country");
	 BufferedReader in= new BufferedReader(new InputStreamReader(System.in));
	 String str="";
	 str=in.readLine();
	 capital=myejb.capitalName(str);
	 System.out.println(capital);
		 }
		 catch(Exception e)
		 {
			 e.printStackTrace();
		 }
	 }


}

Let us try to understand following code snippet:
title

Code Block

title	CodeSnippet
borderStyle	solid

Properties prop=new Properties();
prop.put(Context.INITIAL_CONTEXT_FACTORY, "org.apache.openejb.client.RemoteInitialContextFactory");
prop.put("java.naming.provider.url", "ejbd://localhost:4201");
Context context = new InitialContext(prop);
CountryCapital myejb =(CountryCapital)context.lookup("CountryCapitalBeanRemote");

Info

Useful Information

The above code suggests that which InitialContextFactory to be used to create the InitialContext. Here we are using org.apache.openejb.client.RemoteInitialContextFactory to create the InitialContext.
In this case as the EJB server is the naming service provider and has naming service runnning at Port 4201.
So we need to specify the location of the EJB server. In this case it is ejbd://localhost:4201.
Once this is done we have the context that provides us the ability to lookup and get objects.

Tip

title	Why is the lookup name CountryCapitalBeanRemote ?? :(

This will be discussed in deploy and run section.

Next The next step is to add org.apache.openejb.client.RemoteInitialContextFactory Class class to the build path. This is because the application client needs this Class class to create the InitialContext as explained above.
Right - click on ApplicationClient project under project explorer Project Explorer. Select Properties.
Select Java Build Path. Under Java Build Path select Libraries - -> Add External JARs.
Browse to <GERONIMO_HOME>\repository\org\apache\openejb\openejb-client\3.0-beta-2 and select the jar openejb-client-3.0-beta-2.jar. Select Ok OK.

This completes the Application Client Development.

Deploy and

...

run

This section will take you through the deployment of the EJB application. Later we will run the application client with some sample inputs.

To deploy the EJB application on to server Export the EJB application as a jar file. Right - click on SimpleEJB application and select Export --> EJB JAR File as shown in the figure.

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Browse to the Destination of your choice and select Finish. This will export the SimpleEJB application as a Jar file. This Jar will be later deployed on to Geronimo server

Warning

title	Why to Export EJB? Why cannot I use Eclipse for deploying the EJB application on the server?

Due to some limitation Eclipse is not able to deploy the EJB application on to server. This issue will be fixed very soon.

Start the server and Launch the Administrative Console. Under Applications, select Deploy New and Deploy the SimpleEJB.jar on the server.
the Geronimo server in the Java EE perspective and select Add and Remove Projects....
There should be one deployable project in your workspace. Select Add All >> and then select Finish.

Once the deployment is successful open Once the Deployment is successful. Open <GERONIMO_HOME>/var/log/servergeronimo.log. Find and find the following in server.log :

Code Block

title	Snippet from servergeronimo.log after deployment of SimpleEJB
borderStyle	solid

18:16:39,750 INFO  [startup] Jndi(name=CountryCapitalBeanLocal) --> Ejb(deployment-id=SimpleEJB/CountryCapitalBean)
18:16:39,750 INFO  [startup] Jndi(name=CountryCapitalBeanRemote) --> Ejb(deployment-id=SimpleEJB/CountryCapitalBean)

As can be seen openEJB container after deployment suggests The OpenEJB container is now aware of both the Remote as well as the Local lookup names.
In this case since tutorial the SimpleEJB application and Java Application Client are running on under different instances of JVM. We JVM instances, so we need to have the CountryCapitalBeanRemote as the lookup name for remote access.

Under Eclipse Right - click on the Application Client project and Run as a Java applicationApplication.

Sample Input1Input #1: India

Sample Input2Input #2: China

Sample Input3Input #3: United States Of America

Sample Input4Input #4: France

Child pages

Versions Compared

Old Version 24

New Version Current

Key

Setting up Eclipse IDE for EJB application development

Developing EJB

local interface, EJB

remote interface and Bean

class

Developing a Java Client

Deploy and

run

Child pages

Page History

Versions Compared

Old Version 24

New Version Current

Key

Setting up Eclipse IDE for EJB application development

Developing EJB

local interface, EJB

remote interface and Bean

class

Developing a Java Client

Deploy and

run