#副標=Start with J2EE
#大標=J2EE的商業層（上）：EJB的機制、分類與元素

#作者=文／陳俊吉

=====================<box>===========================
public interface EJBHome extends Remote {

    public abstract EJBMetaData getEJBMetaData()
        throws RemoteException;

    public abstract HomeHandle getHomeHandle()
        throws RemoteException;

    public abstract void remove(Object obj)
        throws RemoteException, RemoveException;

    public abstract void remove(Handle handle)
        throws RemoteException, RemoveException;
}
==========<end>===================================

=============<box>========================
public interface EJBObject extends Remote {

    public abstract EJBHome getEJBHome()
        throws RemoteException;

    public abstract Handle getHandle()
        throws RemoteException;

    public abstract Object getPrimaryKey()
        throws RemoteException;

    public abstract boolean isIdentical(EJBObject ejbobject)
        throws RemoteException;

    public abstract void remove()
        throws RemoteException, RemoveException;
}
==========<end>===================================


==========<box>===================================
public interface SessionBean extends EnterpriseBean {

    public abstract void ejbActivate()
        throws EJBException, RemoteException;

    public abstract void ejbPassivate()
        throws EJBException, RemoteException;

    public abstract void ejbRemove()
        throws EJBException, RemoteException;

    public abstract void setSessionContext(SessionContext sessioncontext)
        throws EJBException, RemoteException;
}
==========<end>===================================


==========<box>===================================
public interface EntityBean extends EnterpriseBean {

    public abstract void ejbActivate()
        throws EJBException, RemoteException;

    public abstract void ejbLoad()
        throws EJBException, RemoteException;

    public abstract void ejbPassivate()
        throws EJBException, RemoteException;

    public abstract void ejbRemove()
        throws RemoveException, EJBException, RemoteException;

    public abstract void ejbStore()
        throws EJBException, RemoteException;

    public abstract void setEntityContext(EntityContext entitycontext)
        throws EJBException, RemoteException;

    public abstract void unsetEntityContext()
        throws EJBException, RemoteException;
} 
==========<end>===================================


==========<box>===================================
public interface MessageDrivenBean extends EnterpriseBean {

    public abstract void ejbRemove()
        throws EJBException;

    public abstract void setMessageDrivenContext(MessageDrivenContext messagedrivencontext)
        throws EJBException;
} 
==========<end>===================================

#
==========<box>===================================
import javax.ejb.CreateException;
import javax.ejb.EJBHome;
import java.rmi.RemoteException;

public interface HelloSessionHome extends EJBHome {
    public HelloSession create() throws CreateException, RemoteException;
}
==========<end>===================================

　　
==========<box>===================================
import javax.ejb.EJBObject;
import java.rmi.RemoteException;

public interface HelloSession extends EJBObject {
    public String sayHello(String name) throws RemoteException;
}
==========<end>===================================

　　
==========<box>===================================

import javax.ejb.CreateException;
import javax.ejb.EJBException;
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;

public class HelloSessionBean implements SessionBean {
    public HelloSessionBean() {
    }

    public void ejbActivate() throws EJBException {
    }

    public void ejbPassivate() throws EJBException {
    }

    public void ejbRemove() throws RemoveException, EJBException {
    }

    public void setSessionContext(SessionContext sessionContext) throws EJBException {
    }

    public void setSessionContext(SessionContext sessionContext) throws EJBException {
    }

    public void ejbCreate() throws CreateException {
    }

    public String sayHello(String name) {
        return "Hello, " + name;
    }
}
==========<end>===================================

==========<box>===================================

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN' 'http://java.sun.com/dtd/ejb-jar_2_0.dtd'>

<ejb-jar>
    <enterprise-beans>
        <session>
            <ejb-name>HelloSessionEJB</ejb-name>
            <home>HelloSessionHome</home>
            <remote>HelloSession</remote>
            <ejb-class>HelloSessionBean</ejb-class>
            <session-type>Stateless</session-type>
            <transaction-type>Container</transaction-type>
        </session>
    </enterprise-beans>
</ejb-jar>
==========<end>===================================

　
================<BOX>=======================
import javax.ejb.CreateException;
import javax.ejb.RemoveException;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.rmi.PortableRemoteObject;
import java.rmi.RemoteException;
import java.util.Properties;

public class HelloSessionClient {
    public static void main(String[] args) throws NamingException, CreateException, RemoteException, RemoveException {
        Properties props = new Properties();
        props.put(InitialContext.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
        props.put(InitialContext.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces");
        props.put(InitialContext.PROVIDER_URL, "jnp://localhost:1099");
        Context ctx = new InitialContext(props);
        Object ref = ctx.lookup("HelloSessionEJB");
        HelloSessionHome home = (HelloSessionHome) PortableRemoteObject.narrow(ref, HelloSessionHome.class);    //Step 1 
        HelloSession remote = home.create();    //Step 2 
        System.out.println(remote.sayHello("EJB")); //Step 3
        remote.remove();    //Step 4
    }
}
================<end>======================
　
================<BOX>======================
import javax.ejb.CreateException;
import javax.ejb.EJBHome;
import javax.ejb.FinderException;
import java.rmi.RemoteException;

public interface HelloEntityHome extends EJBHome {
    public HelloEntity findByPrimaryKey(Integer id) throws RemoteException, FinderException;

    public HelloEntity create(Integer id) throws CreateException, RemoteException;
}
================<end>======================
　　
================<BOX>======================
import javax.ejb.EJBObject;
import java.rmi.RemoteException;

public interface HelloEntity extends EJBObject {
    public Integer getId() throws RemoteException;

    public void setId(Integer id) throws RemoteException;

    public String getName() throws RemoteException;

    public void setName(String name) throws RemoteException;
}
================<end>======================
　　
================<BOX>======================
import javax.ejb.CreateException;
import javax.ejb.EntityBean;
import javax.ejb.EntityContext;

public abstract class HelloEntityBean implements EntityBean {
    public HelloEntityBean() {
    }

    public void ejbActivate() throws EJBException {
    }

    public void ejbLoad() throws EJBException {
    }

    public void ejbPassivate() throws EJBException {
    }

    public void ejbRemove() throws RemoveException, EJBException {
    }

    public void ejbStore() throws EJBException {
    }

    public void setEntityContext(EntityContext entityContext) throws EJBException {
    }

    public void unsetEntityContext() throws EJBException {
    }

    public abstract Integer getId();

    public abstract void setId(Integer id);

    public abstract String getName();

    public abstract void setName(String name);

    public Integer ejbCreate(Integer id) throws CreateException {
        this.setId(id);
        return null;
    }

    public void ejbPostCreate(Integer key) throws CreateException {
    }
}
================<end>======================
　
================<BOX>======================
		……前略
        </session>
        <entity>
            <ejb-name>HelloEntityEJB</ejb-name>
            <home>HelloEntityHome</home>
            <remote>HelloEntity</remote>
            <ejb-class>HelloEntityBean</ejb-class>
            <persistence-type>Container</persistence-type>
            <prim-key-class>java.lang.Integer</prim-key-class>
            <reentrant>False</reentrant>
            <cmp-version>2.x</cmp-version[MC1]>
　　　　　　<abstract-schema-name>HelloEntityEJB</abstract-schema-name>
            <cmp-field>
                <field-name>id</field-name>
            </cmp-field>
            <cmp-field>
                <field-name>name</field-name>
            </cmp-field>
            <primkey-field>id</primkey-field>
        </entity>
    </enterprise-beans>
</ejb-jar>
================<end>======================
　
================<BOX>======================
public class HelloEntityClient {
    public static void main(String[] args) throws NamingException, CreateException, RemoteException, FinderException {
        Properties props = new Properties();
        props.put(InitialContext.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
        props.put(InitialContext.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces");
        props.put(InitialContext.PROVIDER_URL, "jnp://localhost:1099");
        Context ctx = new InitialContext(props);
        Object ref = ctx.lookup("HelloEntityEJB");
        HelloEntityHome home = (HelloEntityHome) PortableRemoteObject.narrow(ref, HelloEntityHome.class);
        HelloEntity remote = home.create(new Integer(1));
        System.out.println(remote.getId());
        home.create(new Integer(2));
        remote = home.findByPrimaryKey(new Integer("2"));
        System.out.println(remote.getId());
        home.remove(new Integer(1));
        home.remove(new Integer(2));
    }
}
================<end>======================
　　
================<BOX>======================
import javax.ejb.EJBException;
import javax.ejb.MessageDrivenBean;
import javax.ejb.MessageDrivenContext;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.TextMessage;
import javax.naming.Context;
import javax.naming.InitialContext;

public class HelloMDBBean implements MessageDrivenBean, MessageListener {
    public HelloMDBBean() {
    }

    public void ejbCreate() {
    }

    public void ejbRemove() {
    }

    public void setMessageDrivenContext(MessageDrivenContext messageDrivenContext) throws EJBException {
    }

    public void onMessage(Message message) {
        TextMessage txtMsg;
        txtMsg = (TextMessage) message;
        try {
            System.out.println("onMessage: " + txtMsg.getText());
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
        try {
            Context ctx = new InitialContext();
            HelloSessionHome home = (HelloSessionHome) ctx.lookup("HelloSessionEJB");
            HelloSession remote = home.create();
            System.out.println(remote.sayHello(txtMsg.getText()));
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}
================<end>======================
　　
================<BOX>======================
        ……前略
        </entity>
        <message-driven>
            <ejb-name>HelloMDBEJB</ejb-name>
            <ejb-class>HelloMDBBean</ejb-class>
            <transaction-type>Container</transaction-type>
            <message-driven-destination>
                <destination-type>javax.jms.Queue</destination-type>
            </message-driven-destination>
        </message-driven>
    </enterprise-beans>
</ejb-jar>
================<end>======================
　　
================<BOX>======================
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE jboss PUBLIC '-//JBoss//DTD JBOSS 3.0//EN' 'http://www.jboss.org/j2ee/dtd/jboss_3_0.dtd'>

<jboss>
    <enterprise-beans>
        <message-driven>
            <ejb-name>HelloMDBEJB</ejb-name>
            <destination-jndi-name>queue/testQueue</destination-jndi-name>
        </message-driven>
    </enterprise-beans>
</jboss>
================<end>======================

================<BOX>======================
import javax.jms.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import java.util.Properties;

public class HelloMDBClient {
    public static void main(String[] args) throws JMSException, NamingException {
        Properties props = new Properties();
        props.put(InitialContext.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
        props.put(InitialContext.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces");
        props.put(InitialContext.PROVIDER_URL, "jnp://localhost:1099");
        Context ctx = new InitialContext(props);
        QueueConnectionFactory factory;
        factory = (QueueConnectionFactory) ctx.lookup("ConnectionFactory");
        QueueConnection conn = factory.createQueueConnection();
        Queue queue = (Queue) ctx.lookup("queue/testQueue");
        QueueSession session = conn.createQueueSession(false, QueueSession.AUTO_ACKNOWLEDGE);
        QueueSender sender = session.createSender(queue);
        TextMessage message = session.createTextMessage("This is Sender");
        sender.send(message);
        conn.start();
        System.out.println("Send: " + message.getText());
        conn.close();
    }
}
================<end>======================