简单的对象监听器 观察者设计模式
該代碼實(shí)現(xiàn)了一個(gè)可以注冊(cè)監(jiān)聽(tīng)類的類，如果注冊(cè)了監(jiān)聽(tīng)類，那么在類的一個(gè)方法執(zhí)行前會(huì)執(zhí)行監(jiān)聽(tīng)類的方法。并且該監(jiān)聽(tīng)類方法的參數(shù)就是被監(jiān)聽(tīng)對(duì)象。
監(jiān)聽(tīng)類就是事件監(jiān)聽(tīng)器，被監(jiān)聽(tīng)對(duì)象就是事件源，事件監(jiān)聽(tīng)器的參數(shù)就是事件對(duì)象。
//設(shè)計(jì)一個(gè)事件源，被監(jiān)聽(tīng)器監(jiān)聽(tīng)? Observer（觀察者設(shè)計(jì)模式）
public class Demo2 {
?
?????? public static void main(String[] args) {
?????????????
????????????? Person p = new Person();
????????????? p.registerListener(new PersonListener(){
?
???????????????????? public void doeat(Event e) {
??????????????????????????? Person p = e.getSource();
??????????????????????????? System.out.println(p + "吃個(gè)死");
???????????????????? }
?
???????????????????? public void dorun(Event e) {
??????????????????????????? // TODO Auto-generated method stub
???????????????????? }
????????????????????
?
????????????? });
????????????? p.eat();
?????? }
?
}
?
class Person{
??????
?????? private PersonListener listener;
??????
?????? public void eat(){
????????????? if(listener!=null){
???????????????????? listener.doeat(new Event(this));
????????????? }
?????? }
??????
?????? public void run(){
????????????? if(listener!=null){
???????????????????? listener.dorun(new Event(this));
????????????? }
?????? }
??????
?????? public void registerListener(PersonListener listener){
????????????? this.listener = listener;
?????? }
}
?
interface PersonListener{
??????
?????? public void doeat(Event e);
??????
?????? public void dorun(Event e);
??????
}
?
class Event{
??????
?????? private Person source;
?????? public Event() {
????????????? super();
????????????? // TODO Auto-generated constructor stub
?????? }
?
?????? public Event(Person source) {
????????????? super();
????????????? this.source = source;
?????? }
?
?????? public Person getSource() {
????????????? return source;
?????? }
?
?????? public void setSource(Person source) {
????????????? this.source = source;
?????? }
??????
}
轉(zhuǎn)載于:https://www.cnblogs.com/flying607/p/3469133.html
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