EJB3 (4)

如果一个远程接口有两个实现，需要用mappedName来区分
首先定义一个远程接口：

@Remote

public interface HelloRemote {

String sayHi(String name);

}

第一个实现：

@Stateless(mappedName="hello")

public class HelloBean implements HelloRemote {

public String sayHi(String name) {

return "Hi " + name;

}

第二个实现：

@Stateless(mappedName="hello2")

public class HelloBean2 implements HelloRemote{

public String sayHi(String name) {

return "Hello " + name;

}

两个无状态会话bean实现了同一个远程接口，但它们的mappedName不一样，还有它们各自重写了sayHi业务方法。部署EJB模块然后测试，首先是Servlet：

@EJB(mappedName="hello2")

private HelloRemote helloBean2;

@EJB(mappedName="hello")

private HelloRemote helloBean;

然后是JSP：

InitialContext ctx = new InitialContext();

HelloRemote helloBean = (HelloRemote)ctx.lookup("hello");

out.println(helloBean.sayHi("Tom"));

HelloRemote helloBean2 = (HelloRemote)ctx.lookup("hello2");

out.println("<br>" + helloBean2.sayHi("Tom"));

呵呵，远程调用也实现了多态

posted on 2008-09-13 00:21 waynemao 阅读(164) 评论(0) 编辑收藏

wayne