运行时直接生成两个天气数据？

老师，我的代码在运行时会直接生成两个天气数据，后面才一次依据5S的频率生成。代码如下

package com.imooc.weather;

import java.util.Random;

public class Weather {

private int tep;

private int hum;

boolean flag=false;

public int getTep() {

return tep;

}

public void setTep(int tep) {

this.tep = tep;

}

public int getHum() {

return hum;

}

public void setHum(int hum) {

this.hum = hum;

}

//生成天气数据的方法

public synchronized void generate() {

//调用一个生成随机数的方法,随机生产温度和湿度

if(flag) {

try {

wait();

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

Random t=new Random();

tep=t.nextInt(40);

this.setTep(tep);

hum=t.nextInt(101);

this.setHum(hum);

System.out.println("生成天气数据"+toString());

flag=true;

notifyAll();

}

//读取天气数据的方法

public synchronized void read() {

if (!flag) {

try {

wait();

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

System.out.println("读取天气数据"+toString());

flag=false;

notifyAll();

}

//重写toString方法

@Override

public String toString() {

return " [温度：" + tep + ", 湿度：" + hum + "]";

}

}

package com.imooc.weather;

public class GenerateWeather implements Runnable {

Weather weather;

public GenerateWeather() {

}

public GenerateWeather(Weather weather) {

this.weather=weather;

weather.generate();

}

@Override

public void run() {

for(int i=1;i<100;i++) {

weather.generate();

try {

Thread.sleep(1000);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}

package com.imooc.weather;

public class ReadWeather implements Runnable {

Weather weather;

public ReadWeather() {

}

public ReadWeather(Weather weather) {

this.weather=weather;

weather.read();

}

@Override

public void run() {

for(int i=1;i<100;i++) {

weather.read();

try {

Thread.sleep(100);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}

package com.imooc.weather;

public class WeatherTest {

public static void main(String[] args) {

// TODO Auto-generated method stub

Weather w=new Weather();

GenerateWeather g=new GenerateWeather(w);

ReadWeather r=new ReadWeather(w);

new Thread(g).start();

new Thread(r).start();

}

}