jboss 4.0 Ejb helloworld
开发环境: java sdk 1.4.2,jboss 4.0,windows 2003
开发sessionbean EJB最少也需要三个class,remote interface,home interface,and bean implementation(bean行为).
1. remote interface 用来揭示EJB对外的一些方法.
package helloWorld; import javax.ejb.EJBObject;
import java.rmi.RemoteException;
public interface RemoteHello extends EJBObject
{ public String HelloEcho(String inputString) throws RemoteException; }
2.home interface 是用来规定怎样创建一个实现remote interface的bean.
package helloWorld;
import java.io.Serializable;
import java.rmi.RemoteException;
import javax.ejb.CreateException;
import javax.ejb.EJBHome;
public interface HomeHello extends EJBHome
{ RemoteHello create() throws RemoteException, CreateException; }
3.bean implementation 是提供方法的实现,这些方法在上述两种interface中都有规定了.
package helloWorld;
import java.rmi.RemoteException;
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;
public class HelloBean implements SessionBean{
public String HelloEcho(String inputString) {
System.out.println("Someone called 'Hello Echo Successed!'");
return "*********" + inputString + "*********"; }
/** Empty method body */
public void ejbCreate() {
System.out.println("Ejb 4 is creating!...");}
/** Every ejbCreate() method ALWAYS needs a corresponding ejbPostCreate () method with exactly the same parameter types. */
public void ejbPostCreate() {}
/** Empty method body */
public void ejbRemove() {
System.out.println("Ejb 4 is removing!...");}
/** Empty method body */
public void ejbActivate() {
System.out.println("Ejb 4 is activating!...");}
/** Empty method body */
public void ejbPassivate()
{}
/** Empty method body */
public void setSessionContext(SessionContext sc)
{}
}
部署jar
这些classes必须打包进一个JAR文件中,JAR文件中包含了目录结构和包的层次.在本例中, 这些classes是在包helloworld,这样他们需要在目录helloWorld/ 下.
部署发布描述器ejb-jar.xml和jboss.xml
在JAR文档创建之前,还需要一个叫META-INF的目录,这是存放部署发布描述器的(一般叫ejb-jar.xml).
<?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>
<description>Neosue Helloworld Sample Application</description>
<display-name>Helloworld EJB</display-name>
<enterprise-beans>
<session>
<ejb-name>Helloworld</ejb-name>
<!-- home interface -->
<home>helloWorld.HomeHello</home>
<!-- remote interface -->
<remote>helloWorld.RemoteHello</remote>
<!-- bean implementation -->
