java监听器的实现和原理详解

package com.ssm.listener.robotListener;

/**
 * 事件源：机器人
 */
public class Robot {

 private RobotListener listener;

 /**
  * 注册机器人监听器
  * @param listener
  */
 public void registerListener(RobotListener listener){
  this.listener = listener;
 }

 /**
  * 工作
  */
 public void working(){
  if(listener!=null){
   Even even = new Even(this);
   this.listener.working(even);
  }
  System.out.println("机器人开始工作......");
 }

 /**
  * 跳舞
  */
 public void dancing(){
  if(listener!=null){
   Even even = new Even(this);
   this.listener.dancing(even);
  }
  System.out.println("机器人开始跳舞......");
 }
}

package com.ssm.listener.robotListener;

/**
 * 事件对象
 */
public class Even {

 private Robot robot;

 public Even(){
  super();
 }
 public Even(Robot robot){
  super();
  this.robot = robot;
 }


 public Robot getRobot() {
  return robot;
 }

 public void setRobot(Robot robot) {
  this.robot = robot;
 }
}

package com.ssm.listener.robotListener;

/**
 * 事件监听器
 */
public interface RobotListener {

 public void working(Even even);
 public void dancing(Even even);
}

package com.ssm.listener.robotListener;

public class MyRobotListener implements RobotListener{
 @Override
 public void working(Even even) {
  Robot robot = even.getRobot();
  System.out.println("机器人工作提示：请看管好的你机器人，防止它偷懒！");
 }

 @Override
 public void dancing(Even even) {
  Robot robot = even.getRobot();
  System.out.println("机器人跳舞提示：机器人跳舞动作优美，请不要走神哦！");
 }
}

package com.ssm.listener.robotListener;

public class TestListener {

 public static void main(String[] args) {
  Robot robot = new Robot();
  robot.registerListener(new MyRobotListener());
  robot.working();
  robot.dancing();
 }
}