content/hello-world.mdtext - tomee-site - Git at Google

 Title: Hello World
 This page shows the basic steps required to create, build, and run an EJB
 and EJB client in its most minimum form.  It does not hide steps or rely on
 special build tools or IDEs and is about the most stripped down you can
 get.

 _See the [Examples](examples.html)
  page for a full list of examples that range from [@Stateles|Simple Stateless Example]
  and [@Stateful|Simple Stateful Example]
  beans, to [Dependency Injection|Injection of env-entry Example]
 , JDBC [DataSources|Injection of DataSource Example]
 , JPA [EntityManagers|Injection of EntityManager Example]
  and more._

 <a name="HelloWorld-AbasicEJBexample"></a>
 ## A basic EJB example

 Here are some basic steps you need to perform to get started with OpenEJB

 1. Download and install OpenEJB
 1. Setup your development environment
 1. Write an EJB
 1. Write an EJB client
 1. Start the server
 1. Deploy the EJB
 1. Run the client
 1. Stop the server

 <a name="HelloWorld-DownloadandinstallOpenEJB"></a>
 ## Download and install OpenEJB

 This example pertains to OpenEJB 3.0 which can be [downloaded here](http://archive.apache.org/dist/openejb/3.0)
 .  Once you have downloaded OpenEJB, you can then simply extract the
 contents of the downloaded file to whichever directory you want to install
 OpenEJB in.

 After extracting the file contents, you should now see a directory named
 openejb-3.0. If you look under this directory, you will find a few more
 directories:
 - *bin*: Contains commands to start/stop the server (You can also do a lot
 of other stuff like deploy/undeploy, but we will just talk about things
 needed to get you started)
 - *lib*: Contains several jar files (you only need of few of these jars in
 your classpath to do EJB development)
 - *apps*: Once you create your EJB's and jar them up, you can place your
 jar file in this directory and start the server. The server will
 automatically deploy all the EJB's contained in this JAR.
 - *conf*: This directory contains all the configuration files. Although you
 may not see any file except for a README.txt file right now, but after you
 start the server, the required configuration files will be automatically
 created. It is highly recommeded to read the README.txt file under this
 directory
 - *logs*: Contains log files.

 <a name="HelloWorld-Setupyourdevelopmentenvironment"></a>
 ## Setup your development environment

 <a name="HelloWorld-Createaworkingdirectory"></a>
 ### Create a working directory
 Assuming you are in your home directory, create a directory named projects

     karan@poweredge:~$ mkdir projects

 Go to the projects directory

     karan@poweredge:~$ cd projects

 We will do all our work in this directory.
 <a name="HelloWorld-InstallJava"></a>
 ### Install Java
 Download and install Java (version 5 or higher). Also set it up so that you
 can run the java and javac commands from any directory
 <a name="HelloWorld-SetOPENEJB_HOME"></a>
 ### Set OPENEJB_HOME
 We will setup this variable to refer to the openejb install location.

     karan@poweredge:~/projects$ export
 OPENEJB_HOME=/home/karan/install/openejb-3.0

 <a name="HelloWorld-WriteanEJB"></a>
 ## Write an EJB
 Whatever files you create should be placed under the projects directory
 <a name="HelloWorld-CreatetheRemoteInterface"></a>
 ### Create the Remote Interface
 Using your favorite editor, create a file named Hello.java (shown below)

     package org.acme;
     import javax.ejb.Remote;
     @Remote
     public interface Hello{
     	public String sayHello();
     }


 <a name="HelloWorld-CreatetheBeanClass"></a>
 ### Create the Bean Class
 Now create a file named HelloBean.java (shown below)

     package org.acme;
     import javax.ejb.Stateless;
     @Stateless
     public class HelloBean implements Hello{
     	public String sayHello(){
     		return "Hello World!!!!";
     	}
     }


 <a name="HelloWorld-Compilethesourcecode"></a>
 ### Compile the source code
 Since we have imported the javax.ejb.Stateless and javax.ejb.Remote
 annotations, we need these in our classpath to compile our source code.
 These annotations can be found in the $OPENEJB_HOME/lib/javaee-5.0-1.jar.
 Lets compile our source (make sure you are in the projects directory)

     karan@poweredge:~/projects$ javac -cp $OPENEJB_HOME/lib/javaee-5.0-1.jar -d
 . *.java

 The above will compile all the .java files and also create the required
 packages. You should now see a package named org under the projects
 directory. All class files should be under org/acme directory.
 <a name="HelloWorld-PackagetheEJB"></a>
 ### Package the EJB
 To package the EJB into a JAR, run the following command while you are in
 the projects directory

     karan@poweredge:~/projects$ jar cvf hello.jar org

 The above command will package everything under the org directory
 (including the org directory itself) into a jar file named hello.jar. Below
 is the output from running the above command:

     karan@poweredge:~/projects$ jar cvf hello.jar org
     added manifest
     adding: org/(in = 0) (out= 0)(stored 0%)
     adding: org/acme/(in = 0) (out= 0)(stored 0%)
     adding: org/acme/Hello.class(in = 203) (out= 168)(deflated 17%)
     adding: org/acme/HelloBean.class(in = 383) (out= 275)(deflated 28%)

 <a name="HelloWorld-WriteanEJBClient"></a>
 ## Write an EJB Client
 Now we will write a Client class which will lookup the EJB , invoke the
 sayHello() business method and print the value returned from the method.
 While you are in the projects directory, create a new file named
 HelloClient.java . Add the following to this file:

     package org.acme;
     import java.util.Properties;
     import javax.naming.InitialContext;
     import javax.naming.Context;
     import javax.rmi.PortableRemoteObject;
     public class HelloClient{
             public static void main(String[]
  args) throws Exception{
     		Properties props = new Properties();

 props.put(Context.INITIAL_CONTEXT_FACTORY,"org.apache.openejb.client.RemoteInitialContextFactory");
     		props.put(Context.PROVIDER_URL,"ejbd://127.0.0.1:4201");
     		Context ctx = new InitialContext(props);
     		Object ref = ctx.lookup("HelloBeanRemote");
     		Hello h =
 (Hello)PortableRemoteObject.narrow(ref,Hello.class);
     		String result = h.sayHello();
     		System.out.println(result);
     	}
     }


 <a name="HelloWorld-CompileHelloClient.java"></a>
 ### Compile HelloClient.java
 Run the following command:

     karan@poweredge:~/projects$ javac  -d . HelloClient.java

 <a name="HelloWorld-StarttheServer"></a>
 ## Start the Server
 Go to the OpenEJB install directory (i.e. OPENEJB_HOME) and run the
 following command:

     karan@poweredge:~/install/openejb-3.0$ bin/openejb start

 Once the Server starts, you will see an output similar to the below in your
 console:

     karan@poweredge:~/install/openejb-3.0$ bin/openejb start
     Apache OpenEJB 3.0    build: 20070926-12:34
     http://tomee.apache.org/
     OpenEJB ready.
     [OPENEJB:init]
  OpenEJB Remote Server
       ** Starting Services **
       NAME		       IP	       PORT
       httpejbd	       0.0.0.0	       4204
       telnet	       0.0.0.0	       4202
       ejbd		       0.0.0.0	       4201
       hsql		       0.0.0.0	       9001
       admin thread	       0.0.0.0	       4200
     -------
     Ready!

 Take out a minute to browse through the conf and logs directories. You
 should now see some configuration and log files under the respective
 directories.
 <a name="HelloWorld-DeploytheEJB"></a>
 ## Deploy the EJB
 We will now use the deploy command to deploy the EJB in hello.jar. While
 you are in the projects directory, run the following command:

     karan@poweredge:~/projects$ $OPENEJB_HOME/bin/openejb deploy hello.jar

 The above command should give you the following output:

     karan@poweredge:~/projects$ $OPENEJB_HOME/bin/openejb deploy hello.jar
     Application deployed successfully at "hello.jar"
     App(id=/home/karan/projects/hello.jar)
         EjbJar(id=hello.jar, path=/home/karan/projects/hello.jar)
     	Ejb(ejb-name=HelloBean, id=HelloBean)
     	    Jndi(name=HelloBeanRemote)

 Notice how the output neatly lays out various deployment details. One thing
 you might want to note from the output is the JNDI name. This is the JNDI
 name we used in the client to lookup the EJB
 <a name="HelloWorld-RuntheClient"></a>
 ## Run the Client
 While you are in the projects directory, run the following command to run
 the client:

     karan@poweredge:~/projects$ java -cp
 $OPENEJB_HOME/lib/openejb-client-3.0.jar:$OPENEJB_HOME/lib/javaee-5.0-1.jar:.
  org.acme.HelloClient

 The above should give you the following output:

     Hello World!!!!

 <a name="HelloWorld-Help!,itdidn'tworkforme!!."></a>
 ## Help! , it didn't work for me!!.
 No problem, we are here to help. Just send us an email at
 users@tomee.apache.org. If possible, send us the contents of
 logs/openejb.log file in the email.

 <a name="HelloWorld-Lookingformore?"></a>
 #  Looking for more?

 More EJB 3.0 examples, sample applications, tutorials and howtos available [here](examples.html)
 .
	Title: Hello World
	This page shows the basic steps required to create, build, and run an EJB
	and EJB client in its most minimum form. It does not hide steps or rely on
	special build tools or IDEs and is about the most stripped down you can
	get.

	_See the [Examples](examples.html)
	page for a full list of examples that range from [@Stateles\|Simple Stateless Example]
	and [@Stateful\|Simple Stateful Example]
	beans, to [Dependency Injection\|Injection of env-entry Example]
	, JDBC [DataSources\|Injection of DataSource Example]
	, JPA [EntityManagers\|Injection of EntityManager Example]
	and more._

	<a name="HelloWorld-AbasicEJBexample"></a>
	## A basic EJB example

	Here are some basic steps you need to perform to get started with OpenEJB

	1. Download and install OpenEJB
	1. Setup your development environment
	1. Write an EJB
	1. Write an EJB client
	1. Start the server
	1. Deploy the EJB
	1. Run the client
	1. Stop the server

	<a name="HelloWorld-DownloadandinstallOpenEJB"></a>
	## Download and install OpenEJB

	This example pertains to OpenEJB 3.0 which can be [downloaded here](http://archive.apache.org/dist/openejb/3.0)
	. Once you have downloaded OpenEJB, you can then simply extract the
	contents of the downloaded file to whichever directory you want to install
	OpenEJB in.

	After extracting the file contents, you should now see a directory named
	openejb-3.0. If you look under this directory, you will find a few more
	directories:
	- bin: Contains commands to start/stop the server (You can also do a lot
	of other stuff like deploy/undeploy, but we will just talk about things
	needed to get you started)
	- lib: Contains several jar files (you only need of few of these jars in
	your classpath to do EJB development)
	- apps: Once you create your EJB's and jar them up, you can place your
	jar file in this directory and start the server. The server will
	automatically deploy all the EJB's contained in this JAR.
	- conf: This directory contains all the configuration files. Although you
	may not see any file except for a README.txt file right now, but after you
	start the server, the required configuration files will be automatically
	created. It is highly recommeded to read the README.txt file under this
	directory
	- logs: Contains log files.

	<a name="HelloWorld-Setupyourdevelopmentenvironment"></a>
	## Setup your development environment

	<a name="HelloWorld-Createaworkingdirectory"></a>
	### Create a working directory
	Assuming you are in your home directory, create a directory named projects

	karan@poweredge:~$ mkdir projects

	Go to the projects directory

	karan@poweredge:~$ cd projects

	We will do all our work in this directory.
	<a name="HelloWorld-InstallJava"></a>
	### Install Java
	Download and install Java (version 5 or higher). Also set it up so that you
	can run the java and javac commands from any directory
	<a name="HelloWorld-SetOPENEJB_HOME"></a>
	### Set OPENEJB_HOME
	We will setup this variable to refer to the openejb install location.

	karan@poweredge:~/projects$ export
	OPENEJB_HOME=/home/karan/install/openejb-3.0

	<a name="HelloWorld-WriteanEJB"></a>
	## Write an EJB
	Whatever files you create should be placed under the projects directory
	<a name="HelloWorld-CreatetheRemoteInterface"></a>
	### Create the Remote Interface
	Using your favorite editor, create a file named Hello.java (shown below)

	package org.acme;
	import javax.ejb.Remote;
	@Remote
	public interface Hello{
	public String sayHello();
	}


	<a name="HelloWorld-CreatetheBeanClass"></a>
	### Create the Bean Class
	Now create a file named HelloBean.java (shown below)

	package org.acme;
	import javax.ejb.Stateless;
	@Stateless
	public class HelloBean implements Hello{
	public String sayHello(){
	return "Hello World!!!!";
	}
	}


	<a name="HelloWorld-Compilethesourcecode"></a>
	### Compile the source code
	Since we have imported the javax.ejb.Stateless and javax.ejb.Remote
	annotations, we need these in our classpath to compile our source code.
	These annotations can be found in the $OPENEJB_HOME/lib/javaee-5.0-1.jar.
	Lets compile our source (make sure you are in the projects directory)

	karan@poweredge:~/projects$ javac -cp $OPENEJB_HOME/lib/javaee-5.0-1.jar -d
	. *.java

	The above will compile all the .java files and also create the required
	packages. You should now see a package named org under the projects
	directory. All class files should be under org/acme directory.
	<a name="HelloWorld-PackagetheEJB"></a>
	### Package the EJB
	To package the EJB into a JAR, run the following command while you are in
	the projects directory

	karan@poweredge:~/projects$ jar cvf hello.jar org

	The above command will package everything under the org directory
	(including the org directory itself) into a jar file named hello.jar. Below
	is the output from running the above command:

	karan@poweredge:~/projects$ jar cvf hello.jar org
	added manifest
	adding: org/(in = 0) (out= 0)(stored 0%)
	adding: org/acme/(in = 0) (out= 0)(stored 0%)
	adding: org/acme/Hello.class(in = 203) (out= 168)(deflated 17%)
	adding: org/acme/HelloBean.class(in = 383) (out= 275)(deflated 28%)

	<a name="HelloWorld-WriteanEJBClient"></a>
	## Write an EJB Client
	Now we will write a Client class which will lookup the EJB , invoke the
	sayHello() business method and print the value returned from the method.
	While you are in the projects directory, create a new file named
	HelloClient.java . Add the following to this file:

	package org.acme;
	import java.util.Properties;
	import javax.naming.InitialContext;
	import javax.naming.Context;
	import javax.rmi.PortableRemoteObject;
	public class HelloClient{
	public static void main(String[]
	args) throws Exception{
	Properties props = new Properties();

	props.put(Context.INITIAL_CONTEXT_FACTORY,"org.apache.openejb.client.RemoteInitialContextFactory");
	props.put(Context.PROVIDER_URL,"ejbd://127.0.0.1:4201");
	Context ctx = new InitialContext(props);
	Object ref = ctx.lookup("HelloBeanRemote");
	Hello h =
	(Hello)PortableRemoteObject.narrow(ref,Hello.class);
	String result = h.sayHello();
	System.out.println(result);
	}
	}


	<a name="HelloWorld-CompileHelloClient.java"></a>
	### Compile HelloClient.java
	Run the following command:

	karan@poweredge:~/projects$ javac -d . HelloClient.java

	<a name="HelloWorld-StarttheServer"></a>
	## Start the Server
	Go to the OpenEJB install directory (i.e. OPENEJB_HOME) and run the
	following command:

	karan@poweredge:~/install/openejb-3.0$ bin/openejb start

	Once the Server starts, you will see an output similar to the below in your
	console:

	karan@poweredge:~/install/openejb-3.0$ bin/openejb start
	Apache OpenEJB 3.0 build: 20070926-12:34
	http://tomee.apache.org/
	OpenEJB ready.
	[OPENEJB:init]
	OpenEJB Remote Server
	Starting Services
	NAME IP PORT
	httpejbd 0.0.0.0 4204
	telnet 0.0.0.0 4202
	ejbd 0.0.0.0 4201
	hsql 0.0.0.0 9001
	admin thread 0.0.0.0 4200
	-------
	Ready!

	Take out a minute to browse through the conf and logs directories. You
	should now see some configuration and log files under the respective
	directories.
	<a name="HelloWorld-DeploytheEJB"></a>
	## Deploy the EJB
	We will now use the deploy command to deploy the EJB in hello.jar. While
	you are in the projects directory, run the following command:

	karan@poweredge:~/projects$ $OPENEJB_HOME/bin/openejb deploy hello.jar

	The above command should give you the following output:

	karan@poweredge:~/projects$ $OPENEJB_HOME/bin/openejb deploy hello.jar
	Application deployed successfully at "hello.jar"
	App(id=/home/karan/projects/hello.jar)
	EjbJar(id=hello.jar, path=/home/karan/projects/hello.jar)
	Ejb(ejb-name=HelloBean, id=HelloBean)
	Jndi(name=HelloBeanRemote)

	Notice how the output neatly lays out various deployment details. One thing
	you might want to note from the output is the JNDI name. This is the JNDI
	name we used in the client to lookup the EJB
	<a name="HelloWorld-RuntheClient"></a>
	## Run the Client
	While you are in the projects directory, run the following command to run
	the client:

	karan@poweredge:~/projects$ java -cp
	$OPENEJB_HOME/lib/openejb-client-3.0.jar:$OPENEJB_HOME/lib/javaee-5.0-1.jar:.
	org.acme.HelloClient

	The above should give you the following output:

	Hello World!!!!

	<a name="HelloWorld-Help!,itdidn'tworkforme!!."></a>
	## Help! , it didn't work for me!!.
	No problem, we are here to help. Just send us an email at
	users@tomee.apache.org. If possible, send us the contents of
	logs/openejb.log file in the email.

	<a name="HelloWorld-Lookingformore?"></a>
	# Looking for more?

	More EJB 3.0 examples, sample applications, tutorials and howtos available [here](examples.html)
	.