事件监听器原理——事件对象、事件监听器、事件源

package cn.my.demo;



//设计一个监听器

public class Demo2 {

    public static void main(String[] args) {

        Person p=new Person(1001,"张三");

        p.refisterListener(new PersonListener() {            

            public void dorun(Event e) {

                Person p=e.getSource();

                System.out.println("Who is in front of people to have a meal, that is "+p.getName());

            }

            

            public void doeat(Event e) {

                Person p=e.getSource();

                System.out.println("Who in the previous run, that is "+p.getName());

            }

        });

        

        p.eat();

        p.run();

    }

}

//观察者设计模式

class Person{    

    private Integer id ;

    private String name;

    public Integer getId() {

        return id;

    }

    public void setId(Integer id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    

    public Person(Integer id ,String name)

    {

        this.id=id;

        this.name=name;

    }

    //这个就是一个事件源

    private PersonListener listener;

    public void eat(){

        if(listener!=null){

            listener.doeat(new Event(this));

        }

        

        System.out.println("this is eat!");

    }

    public void run(){

        if(listener!=null){

            listener.dorun(new Event(this));

        }

        

        System.out.println("this is run!");

    }

    public void refisterListener(PersonListener listener){

        this.listener=listener;

    }

}



//事件监听器

interface PersonListener{

    public void doeat(Event e);

    public void dorun(Event e);

}



//这个是事件对象

class Event{

    //事件对象   需要封装事件源对象

    private Person source;



    public Person getSource() {

        return source;

    }

    public Event(Person source) {

        super();

        this.source = source;

    }

    public Event() {

        super();

    }

    public void setSource(Person source) {

        this.source = source;

    }

}