代码如下：

Weather类

public class Weather {
private double temptrue;
private double hideity;
public boolean b = true;
public double getTemptrue() {
return temptrue;
    }

public void setTemptrue(double temptrue) {
this.temptrue = temptrue;
    }

public double getHideity() {
return hideity;
    }

public void setHideity(double hideity) {
this.hideity = hideity;
    }

public void generate(){
if (!b){
try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

this.setTemptrue(Math.random());
this.setHideity(Math.random());
        System.out.println("生成天气："+this.toString());
b=false;
        notifyAll();
        }




public void read(){
if (b){
try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("读取天气" + this.toString());
b=true;
        notifyAll();

    }

@Override
    public String toString() {
return "天气{" +
"温度=" + temptrue +
", 湿度=" + hideity +
'}';
    }
}

GenerateWeather类
public class GenerateWeather implements Runnable{


    Weather weather;
    GenerateWeather(Weather weather){
        this.weather = weather;
    }
    @Override
    public void run() {
        while (true){

            weather.generate();
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
    }
    }

ReadWeather类
​public class ReadWeather implements Runnable{
    Weather weather;
    ReadWeather(Weather weather){
        this.weather = weather;
    }

    @Override
    public void run() {
        while (true){
            weather.read();
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }

    }
}

测试类
public class WeatherTest {
    public static void main(String[] args) {
        Weather weather = new Weather();
            new Thread(new GenerateWeather(weather)).start();
            new Thread(new ReadWeather(weather)).start();


    }
}    

运行报错如下：
​Exception in thread "Thread-1" java.lang.IllegalMonitorStateException
	at java.lang.Object.wait(Native Method)
	at java.lang.Object.wait(Object.java:502)
生成天气：天气{温度=0.31717090087249256, 湿度=0.39180791972688567}
	at com.testWeather.Weather.read(Weather.java:45)
	at com.testWeather.ReadWeather.run(ReadWeather.java:12)
	at java.lang.Thread.run(Thread.java:745)
Exception in thread "Thread-0" java.lang.IllegalMonitorStateException
	at java.lang.Object.notifyAll(Native Method)
	at com.testWeather.Weather.generate(Weather.java:36)
	at com.testWeather.GenerateWeather.run(GenerateWeather.java:14)
	at java.lang.Thread.run(Thread.java:745)