/* 观察者设计模式：
作用： 当一个对象发生指定的动作时，要通知另外一个对象做出相应的处理，类似于事件触发和监听处理。
其他名称:
发布--订阅
模型--视图
源--收听
从属者模式
需求：编写一个气象站和人两个类，当气象更新的时候，要通知人做出相应的处理。
步骤：
1. 定义一个接口，将观察者要通知执行的方法定义在接口中：
2. 当前对象维护接口的引用，当对象发生指定的动作时即可调用指定的处理方法； */
package com.jin.michael;
import java.util.ArrayList;
import java.util.Random;
//定义一个集合来定义规则
interface Weather{public void notifyWeather(String weather);
}
//天气台类
class WeatherStation{
String[] weathers = {"晴天", "阴天", "小雨", "大雨", "冰雹"};
//当前天气String weather;
//添加观察者
ArrayListllistener = new ArrayList();
public void addListener(Weather weather){
llistener.add(weather);
}
//开始工作方法
public void startWork() throws InterruptedException{
//每1-1.5秒跟新一次天气
final Random random = new Random();
new Thread(){
public void run() {
while(true){
int sec = random.nextInt(501)+1000;
try {
Thread.sleep(sec);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
updateWeather();
for(Weather w : llistener){
w.notifyWeather(weather);
}
}
}
}.start();
}
//更新天气
public void updateWeather(){
Random random = new Random();
int index = random.nextInt(weathers.length);
weather = weathers[index];
System.out.println("当前天气是:" + weather);
}
}
//工人类，要收听天气，必须实现规则,根据天气做出相应的处理
class Worker implements Weather{
String name;
public Worker(String name){
this.name = name;
}
public void notifyWeather(String weather){
if("晴天".equals(weather)){
System.out.println(weather+":出去旅游");
}
else if("阴天".equals(weather)){
System.out.println(weather+"去看书");
}
else if("小雨".equals(weather)){
System.out.println(weather+"要带上伞");
}
else if("大雨".equals(weather)){
System.out.println(weather+"去吃火锅");
}
else if("冰雹".equals(weather)){
System.out.println(weather+"在家睡觉");
}
}
}
class Dog implements Weather{
@Override
public void notifyWeather(String weather) {
if("晴天".equals(weather)){
System.out.println(weather+":唱歌");
}
else if("阴天".equals(weather)){
System.out.println(weather+"吃饭");
}
else if("小雨".equals(weather)){
System.out.println(weather+"喝酒");
}
else if("大雨".equals(weather)){
System.out.println(weather+"旅游");
}
else if("冰雹".equals(weather)){
System.out.println(weather+"游泳");
}
}
}
public class Demo05 {
public static void main(String[] args) throws InterruptedException{
Worker worker = new Worker("小王");
Worker worker1 = new Worker("小成");
Dog d1 = new Dog();
Dog d2 = new Dog();
WeatherStation wStation = new WeatherStation();
wStation.addListener(worker);
wStation.addListener(worker1);
wStation.addListener(d2);
wStation.addListener(d1);
wStation.startWork();
}
}