Jboss EJB 3.0 Stateless Beans

下面有两个例子：一个是标准的statelessBean，一个是简化的statelessbean

Calculator.java             // 计算器的接口：加、减

package org.jboss.tutorial.stateless.bean;

public interface Calculator

{

   int add(int x, int y);

   int subtract(int x, int y);

}

 

 

 

 

 

CalculatorBean.java

package org.jboss.tutorial.stateless.bean;

import javax.ejb.Stateless; 

@Stateless           //标记CalculatorBean 为 stateless bean，为本地和远程接口的实现

public class CalculatorBean implements CalculatorRemote, CalculatorLocal

{

  public int add(int x, int y)

   {

     return x + y;

   } 

   public int subtract(int x, int y)

   {

     return x - y;

   }

}

 

CalculatorLocal.java

package org.jboss.tutorial.stateless.bean;

import javax.ejb.Local;

@Local                    //标记为本地接口，继承了计算器接口

public interface CalculatorLocal extends Calculator

{

}

 

 

 

 

 

 

 

CalculatorRemote.java

package org.jboss.tutorial.stateless.bean;

import javax.ejb.Remote;

@Remote               //标记为远程接口，继承了计算器接口

public interface CalculatorRemote extends Calculator

{

}

 

 

客户端 

Client.java

package org.jboss.tutorial.stateless.client; 

import org.jboss.tutorial.stateless.bean.Calculator;

import org.jboss.tutorial.stateless.bean.CalculatorRemote;

import javax.naming.InitialContext;

public class Client

{

   public static void main(String[] args) throws Exception

   {

      InitialContext ctx = new InitialContext();

      //查找远程接口

      Calculator calculator = (Calculator) ctx.lookup(CalculatorRemote.class.getName());                         

      System.out.println("1 + 1 = " + calculator.add(1, 1));

      System.out.println("1 - 1 = " + calculator.subtract(1, 1));

   }

}

*****************************简化版********************************

 

只需三个程序即可实现StatelessBean功能。

Calculator.java

package org.jboss.tutorial.stateless.bean;

import javax.ejb.Remote;

@Remote             //直接将计算器标记为远程接口

public interface Calculator

{

   int add(int x, int y);

   int subtract(int x, int y);

}

 

 

 

 

CalculatorBean.java

package org.jboss.tutorial.stateless.bean;

import javax.ejb.Stateless;

@Stateless

public class CalculatorBean implements Calculator        //这里实现了计算器接口

{

   public int add(int x, int y)

   {

      return x + y;

   } 

   public int subtract(int x, int y)

   {

      return x - y;

   }

}

 

客户端：

Client.java

package org.jboss.tutorial.stateless.client;

import org.jboss.tutorial.stateless.bean.Calculator;

import javax.naming.InitialContext; 

public class Client

{

   public static void main(String[] args) throws Exception

   {

      InitialContext ctx = new InitialContext();

      Calculator calculator = (Calculator) ctx.lookup(Calculator.class.getName());

                                     //只要查找标记为remote的接口就行了

      System.out.println("1 + 1 = " + calculator.add(1, 1));

      System.out.println("1 - 1 = " + calculator.subtract(1, 1));

   }

} 

 

这里附上log4j.properties 在jboss-EJB-3.0_Preview_5.zip　里面没有这个老是显示缺少appender

log4j.properties

log4j.appender.R=org.apache.log4j.RollingFileAppender

log4j.appender.R.File=record.log

log4j.appender.R.layout=org.apache.log4j.PatternLayout

log4j.appender.R.layout.ConversionPattern=%p  %d{hh:mm:ss} %t %c{1} -%m%n

log4j.appender.R.MaxBackupIndex=1

log4j.appender.R.MaxFileSize=100KB

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) -%m%n

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.rootLogger=stdout,R

 

 

 

 

 

运行：参考installing.html

Windows下

打开命令提示符cmd，到  jboss_home/bin

Run.bat –c all

用ant

先build后run 就行了. 

 

讨论：

简化版是看到jboss-EJB-3.0_Preview_5.zip里面的statefull源码而改写的，在EJB spe 3.0说好像是删除了home这个接口，我觉得简化很多接口更方面，有效的开发j2ee　application