JDBC: ThreadLocal 类

package com.dgd.test;

import java.util.Random;

public class TestTools {
    public static void main(String[] args) {
        MyThread th1=new MyThread();
        th1.start();

        MyThread th2=new MyThread();
        th2.start();
    }
}

class  Tools{
    private  static Random rand=new Random();
    private  static ThreadLocal<Integer> th=new ThreadLocal<>();

    public  static  void setNumber()
    {
        th.set(rand.nextInt(100));
        //这里设置的就是当前线程保存的共享变量，这个共享变量不是之前的多线程之间的共享变量，而是同一个线程在整个生命周期中，使用的共享变量。
    }
    public  static int getNumber(){
        return th.get();
    }
}
class MyThread extends Thread{
    public  void  run(){
        Tools.setNumber();
        for (int i = 0; i <5 ; i++) {
            int number=Tools.getNumber();
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread()+":"+number);
        }
    }
}