Start up JBoss as described in the JBoss Installation and Configuration chapter at the beginning of this workbook.

The database table for this exercise will automatically be created in JBoss’s default database, HypersonicSQL, when the EJB JAR is deployed.

Perform the following steps:

If you need to learn more about the Ant utility, visit the Ant project at the Jakarta web site at http://jakarta.apache.org/ant/index.html.

Ant compiles the Java source code, builds the EJB JAR, and deploys the JAR simply by copying it to JBoss’s deploy directory. If you are watching the JBoss console window, you will notice that JBoss automatically discovers the EJB JAR once it has been copied into the deploy directory, and automatically deploys the bean.

Another particularly interesting thing about building EJB JARs is that there is no special EJB compilation step. Unlike other servers, JBoss does not generate code for client stubs. Instead, it has a lightweight mechanism that creates client proxies when the EJB JAR is deployed, accelerating the development and deployment cycle.

The build.xml file provided for each workbook exercise gives the Ant utility information about how to compile and deploy your Java programs and EJBs. The following build tasks can be executed by typing ant taskname :

Here’s a breakdown of what is contained in build.xml.

<project name="JBoss" default="ejbjar" basedir=".">

The default attribute defines the default target that ant will run if you type only ant on the command line. The basedir attribute tells Ant what directory to run the build in:

  <property environment="env"/>
  <property name="src.dir" value="${basedir}/src/main"/>
  <property name="src.resources" value="${basedir}/src/resources"/>
  <property name="jboss.home" value="${env.JBOSS_HOME}"/>
  <property name="build.dir" value="${basedir}/build"/>
  <property name="build.classes.dir" value="${build.dir}/classes"/>

All the properties defined above are variables that Ant will use throughout the build process. You can see that the JBOSS_HOME environment variable is pulled from the system environment and other directory paths defined:

  <path id="classpath">
        <fileset dir="${jboss.home}/client">
            <include name="**/*.jar"/>
        </fileset>
    <pathelement location="${build.classes.dir}"/>
    <pathelement location="${basedir}/jndi"/>
  </path>

To compile and run the example applications in this workbook, add all the JARS in $JBOSS_HOME/client to the Java classpath. Also notice that build.xml inserts the ${basedir}/jndi directory into the classpath. A jndi.properties file in this directory enables the example programs to find and connect to JBoss’s JNDI server:

  <property name="build.classpath" refid="classpath"/>

  <target name="prepare" >
    <mkdir dir="${build.dir}"/>
    <mkdir dir="${build.classes.dir}"/>
  </target>

The prepare target creates the directories where the Java compiler will place compiled classes:

  <target name="compile" depends="prepare">
    <javac srcdir="${src.dir}"
           destdir="${build.classes.dir}"
           debug="on"
           deprecation="on"
           optimize="off"
           includes="**">
            <classpath refid="classpath"/>
    </javac>
  </target>

The compile target compiles all the Java files under the src/main directory. Notice that it depends on the prepare target; prepare will run before the compile target is executed:

<target name="ejbjar" depends="compile">
  <jar jarfile="build/titan.jar">
    <fileset dir="${build.classes.dir}">
          <include name="com/titan/cabin/*.class"/>
    </fileset>
    <fileset dir="${src.resources}/">
        <include name="**/*.xml"/>
    </fileset>
   </jar>
   <copy file="build/titan.jar"
         todir="${jboss.home}/server/default/deploy"/>
</target>

The ejbjar target creates the EJB JAR file and deploys it to JBoss simply by copying it to JBoss’s deploy directory:

<target name="run.client_41a" depends="ejbjar">
  <java classname="com.titan.clients.Client_1" fork="yes" dir=".">
    <classpath refid="classpath"/>
  </java>
</target>

<target name="run.client_41b" depends="ejbjar">
  <java classname="com.titan.clients.Client_2" fork="yes" dir=".">
    <classpath refid="classpath"/>
  </java>
</target>

The run.client_xxx targets are used to run the example programs in this chapter:

<target name="clean.db">
  <delete dir="${jboss.home}/server/default/db/hypersonic"/>
</target>

The clean.db target cleans the default database used by JBoss for the example programs in this book. Remember, you can only use it when JBoss is not running:

<target name="clean">
  <delete dir="${build.dir}"/>
  <delete file="${jboss.home}/server/default/deploy/titan.jar"/>
</target>
</project>

The clean target removes compiled classes and undeploys the EJB JAR from JBoss by deleting the JAR file in the deploy directory.

You do not need any JBoss-specific files to write a simple EJB. For an entity bean as simple as the Cabin EJB, JBoss creates the appropriate database tables within its embedded database Hypersonic SQL by examining the ejb-jar.xml deployment descriptor.

By default, JBoss uses the <ejb-name> from the bean’s ejb-jar.xml deployment descriptor for the JNDI binding of the bean’s home interface. If you do not like this default, you can override it in a jboss.xml file. Clients use this name to look up an EJB’s home interface. For this example, CabinEJB is bound to CabinHomeRemote.

<jboss>
  <enterprise-beans>
    <entity>
       <ejb-name>CabinEJB</ejb-name>
       <jndi-name>CabinHomeRemote</jndi-name>
    </entity>
  </enterprise-beans>
</jboss>

Two example programs implement the sample clients provided in the EJB book:

package com.titan.clients;

import com.titan.cabin.CabinHomeRemote;
import com.titan.cabin.CabinRemote;

import javax.naming.InitialContext;
import javax.naming.Context;
import javax.naming.NamingException;
import javax.rmi.PortableRemoteObject;
import java.rmi.RemoteException;

public class Client_1 
{
   public static void main(String [] args) 
   {
      try 
      {
         Context jndiContext = getInitialContext( );
         Object ref = jndiContext.lookup("CabinHomeRemote");
         CabinHomeRemote home = (CabinHomeRemote)
            PortableRemoteObject.narrow(ref,CabinHomeRemote.class);   
         CabinRemote cabin_1 = home.create(new Integer(1));
         cabin_1.setName("Master Suite");
         cabin_1.setDeckLevel(1);
         cabin_1.setShipId(1);
         cabin_1.setBedCount(3);
             
         Integer pk = new Integer(1);
            
         CabinRemote cabin_2 = home.findByPrimaryKey(pk);
         System.out.println(cabin_2.getName( ));
         System.out.println(cabin_2.getDeckLevel( ));
         System.out.println(cabin_2.getShipId( ));
         System.out.println(cabin_2.getBedCount( ));

      } 
      catch (java.rmi.RemoteException re){re.printStackTrace( );}
      catch (javax.naming.NamingException ne){ne.printStackTrace( );}
      catch (javax.ejb.CreateException ce){ce.printStackTrace( );}
      catch (javax.ejb.FinderException fe){fe.printStackTrace( );}
   }

   public static Context getInitialContext( ) 
      throws javax.naming.NamingException 
   {
      return new InitialContext( );
   }
}

C:workbookex04_1>ant run.client_41a
Buildfile: build.xml

prepare:

compile:

ejbjar:

run.client_41a:
     [java] Master Suite
     [java] 1
     [java] 1
     [java] 3

run.client_41a:
     [java] javax.ejb.DuplicateKeyException: Entity with primary key 1 already exists
     [java]     at org.jboss.ejb.plugins.cmp.jdbc.JDBCCreateEntityCommand.
execute(JDBCCreateEntityCommand.java:160)
     [java]     at org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager.
createEntity(JDBCStoreManager.java:633)
     [java]     at org.jboss.ejb.plugins.CMPPersistenceManager.
createEntity(CMPPersistenceManager.java:253)
     [java]     at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.
createEntity(CachedConnectionInterce
...
     [java]     at org.jboss.invocation.InvokerInterceptor.invoke(InvokerInterceptor.
java:92)
     [java]     at org.jboss.proxy.TransactionInterceptor.
invoke(TransactionInterceptor.java:77)
     [java]     at org.jboss.proxy.SecurityInterceptor.invoke(SecurityInterceptor.
java:80)
     [java]     at org.jboss.proxy.ejb.HomeInterceptor.invoke(HomeInterceptor.java:
175)
     [java]     at org.jboss.proxy.ClientContainer.invoke(ClientContainer.java:82)
     [java]     at $Proxy0.create(Unknown Source)
     [java]     at com.titan.clients.Client_1.main(Client_1.java:22)

run.client_41b:
     [java] PK=1, Ship=1, Deck=1, BedCount=3, Name=Master Suite
     [java] PK=2, Ship=1, Deck=1, BedCount=2, Name=Suite 100
     [java] PK=3, Ship=1, Deck=1, BedCount=3, Name=Suite 101
     [java] PK=4, Ship=1, Deck=1, BedCount=2, Name=Suite 102
     [java] PK=5, Ship=1, Deck=1, BedCount=3, Name=Suite 103
     [java] PK=6, Ship=1, Deck=1, BedCount=2, Name=Suite 104
     [java] PK=7, Ship=1, Deck=1, BedCount=3, Name=Suite 105
     [java] PK=8, Ship=1, Deck=1, BedCount=2, Name=Suite 106
     ...
     [java] PK=90, Ship=3, Deck=3, BedCount=3, Name=Suite 309
     [java] PK=91, Ship=3, Deck=4, BedCount=2, Name=Suite 400
     [java] PK=92, Ship=3, Deck=4, BedCount=3, Name=Suite 401
     [java] PK=93, Ship=3, Deck=4, BedCount=2, Name=Suite 402
     [java] PK=94, Ship=3, Deck=4, BedCount=3, Name=Suite 403
     [java] PK=95, Ship=3, Deck=4, BedCount=2, Name=Suite 404
     [java] PK=96, Ship=3, Deck=4, BedCount=3, Name=Suite 405
     [java] PK=97, Ship=3, Deck=4, BedCount=2, Name=Suite 406
     [java] PK=98, Ship=3, Deck=4, BedCount=3, Name=Suite 407
     [java] PK=99, Ship=3, Deck=4, BedCount=2, Name=Suite 408
     [java] PK=100, Ship=3, Deck=4, BedCount=3, Name=Suite 409

Every EJB in JBoss is deployed and managed as a JMX MBean. You can view and manage EJBs deployed within JBoss through your web browser by accessing the JMX management console available at http://localhost:8080/jmx-console/ (Figure 22-1).

Figure 22-1. The JMX management console

Click on the jndiName=CabinHomeRemote,service=EJB link shown in Figure 22-1. Entity beans have two management functions. You can flush the entity bean’s cache or view the number of cached objects for it. To flush, click on the flushCache button. To view the number of cached beans, click on the getCacheSize button (Figure 22-2).

Figure 22-2. Managing entity beans from the console