java实现23种设计模式-观察者模式

package design_model.ObServer;
public interface Subject {
    //注册观察者
    public void registerObserver(ObServer obServer);
    //移除观察者
    public void removeObserver(ObServer obServer);
    //遍历所有观察者
    public void notifyObserver();
}

package design_model.ObServer;
//观察者接口
public interface ObServer {
    public void update(float temperatrue,float pressure,float humidity);
}

//当前观察者
public class CurrentConditions implements ObServer {
    //温度，气压，湿度
    private float temperature;
    private float pressure;
    private float humidity;
    //更新天气
    @Override
    public void update(float temperature, float pressure, float humidity) {
        this.temperature = temperature;
        this.pressure = pressure;
        this.humidity = humidity;
        display();
    }
    private void display() {
        System.out.println("温度为:" + temperature);
        System.out.println("大气压:" + pressure);
        System.out.println("湿度为:" + humidity);
    }
}

package design_model.ObServer;
import java.util.ArrayList;
/**
 * 包含最新的天气状况
 * 含有观察者集合，使用ArrayList集合管理
 * 当数据更新时，就主动调用ArrayList，通知所有的接入方，让他们接收消息
 */
public class WeatherData implements Subject{
    //温度，气压，湿度
    private float temperature;
    private float pressure;
    private float humidity;
    private ArrayList<ObServer> obServers;
    public WeatherData(){
        obServers = new ArrayList<>();
    }
    public float getTemperature() {
        return temperature;
    }
    public void setTemperature(float temperature) {
        this.temperature = temperature;
    }
    public float getPressure() {
        return pressure;
    }
    public void setPressure(float pressure) {
        this.pressure = pressure;
    }
    public float getHumidity() {
        return humidity;
    }
    public void setHumidity(float humidity) {
        this.humidity = humidity;
    }
    public void setData(float temperature,float pressure,float humidity){
        this.temperature = temperature;
        this.pressure = pressure;
        this.humidity = humidity;
        dataChange();
    }
    private void dataChange() {
        notifyObserver();
    }
    @Override
    public void registerObserver(ObServer obServer) {
        obServers.add(obServer);
    }
    @Override
    public void removeObserver(ObServer obServer) {
        obServers.remove(obServer);
    }
    //遍历所有的观察者，并通知
    @Override
    public void notifyObserver() {
        for (int i = 0; i < obServers.size(); i++) {
            obServers.get(i).update(this.temperature,this.pressure,this.humidity);
        }
    }
}

public class Client {
    public static void main(String[] args) {
        //创建一个WeatherData
        WeatherData weatherData = new WeatherData();
        //创建观察者
        CurrentConditions currentConditions = new CurrentConditions();
        //注册到WeatherData中
        weatherData.registerObserver(currentConditions);
        //测试
        System.out.println("通知各个观察者，看看信息");
        weatherData.setData(10f,100f,30.9f);
    }
}