EJB2.0有状态SessionBean

package lavasoft.testejb20yzt; 

import javax.ejb.SessionBean; 
import javax.ejb.SessionContext; 

/** 
* Bean类 
* 所有具体的业务逻辑都在此类里面，此类不抛出远程异常 
* 
* @author leizhimin 2010-3-31 15:26:53 
*/ 
public  class HelloStatefulBean  implements SessionBean { 
         private SessionContext context; 
         private String someOne; 

         /** 
         * 业务方法 
         * 
         * @return Hello的消息 
         */ 
         public String sayHello() { 
                System.out.println( "HelloStatefulBean: sayHello() is called!"); 
                 return  "Hello, " + someOne +  "!"; 
        } 

         /** 
         * 必须有这个方法，这是EJB的一条原则，这个方法不是来自SessionBean接口的 
         * 这只能是一个有状态的bean,因为无状态的bean除了无参数的create方法外，不能有其他的创建方法 
         */ 
         public  void ejbCreate(String someOne) { 
                System.out.println( "HelloStatefulBean: ejbCreate(String someOne) is called!"); 
                 this.someOne = someOne; 
        } 

         //-------下面四个方法是来自SessionBean的，必须写出来，但没啥用------- 
         public  void ejbActivate() { 
                System.out.println( "HelloStatefulBean: ejbActivate() is called!"); 
        } 

         public  void ejbPassivate() { 
                System.out.println( "HelloStatefulBean: ejbPassivate() is called!"); 
        } 

         public  void ejbRemove() { 
                System.out.println( "HelloStatefulBean: ejbRemove() is called!"); 
        } 

         public  void setSessionContext(SessionContext sessionContext) { 
                System.out.println( "HelloStatefulBean: setSessionContext() is called!"); 
                context = sessionContext; 
        } 
}

package lavasoft.testejb20yzt; 

import javax.ejb.EJBObject; 
import java.rmi.RemoteException; 

/** 
* 组件接口 
* 所有的业务方法都要在此接口中声明 
* 
* @author leizhimin 2010-3-31 15:31:10 
*/ 
public  interface HelloStateful  extends EJBObject { 
         /** 
         * 业务方法，组件接口中的业务方法必须抛出RemoteException 
         * 
         * @return 
         * @throws java.rmi.RemoteException 
         */ 
         public String sayHello()  throws RemoteException; 
}

package lavasoft.testejb20yzt; 

import javax.ejb.CreateException; 
import javax.ejb.EJBHome; 
import java.rmi.RemoteException; 

/** 
* Home接口 
* Home接口必须扩展EJBHome或者EJBLocalHome接口 
* 客户使用Home接口来请求组件接口的一个引用 
* 可以将Home接口看做是一个工厂，它能制造Bean的引用个，而且能向客户分配bean引用 
* 
* @author leizhimin 2010-3-31 15:32:06 
*/ 
public  interface HelloStatefulHome  extends EJBHome { 
         public HelloStateful create(String someOne)  throws CreateException, RemoteException; 
}

package lavasoft.client; 

import lavasoft.testejb20yzt.HelloStateful; 
import lavasoft.testejb20yzt.HelloStatefulHome; 

import javax.ejb.CreateException; 
import javax.naming.InitialContext; 
import javax.naming.NamingException; 
import javax.rmi.PortableRemoteObject; 
import java.rmi.RemoteException; 
import java.util.Properties; 

/** 
* 客户端代码 
* 客户端会依赖组件接口和Home接口 
* 
* @author leizhimin 2010-3-31 15:54:20 
*/ 
public  class TestStatefulSessionBeanClient { 
         public  static  void main(String[] args)  throws NamingException, CreateException, RemoteException { 
                Properties props =  new Properties(); 
                props.setProperty( "java.naming.factory.initial",  "org.jnp.interfaces.NamingContextFactory"); 
                props.setProperty( "java.naming.provider.url",  "localhost:1099"); 
                 //初始化JNDI上下文环境,因为客户端不知道JBOSS的环境 
                InitialContext ctx =  new InitialContext(props); 
                 //检索指定的对象 
                Object objref = ctx.lookup( "ejb/helloStatefulEJB"); 
                 //强制转换为所需类型的对象 
                HelloStatefulHome home = (HelloStatefulHome) PortableRemoteObject.narrow(objref, HelloStatefulHome. class); 
                 //通过home对象创建一个组件接口对象 
                HelloStateful hello = home.create( "StatefulEJB"); 
                 //通过组件接口对象调用业务方法 
                String msg = hello.sayHello(); 
                System.out.println(msg); 
        } 
}