多线程ThreadLocal类

所有线程共享的变量可以用public static修饰 ，每一个线程自己独有的共享变量可以用ThreadLocal修饰。

package com.hanw.testThread.oneByOne;

import java.util.Date;

public class ThreadLocal1 {
	public static void main(String[] args) throws InterruptedException {
		ThreadA1 a = new ThreadA1();
		a.start();
		Thread.sleep(1000);
		ThreadB1 b = new ThreadB1();
		b.start();
		
		
	}
}

class Tools {
	public static ThreadLocal<Date> t1 = new ThreadLocal<Date>();
}

class ThreadA1 extends Thread{	
	@Override
	public void run() {
		for (int i=0;i<20;i++) {
			if (Tools.t1.get() == null) {
				Tools.t1.set(new Date());
			}
			System.out.println("A" + Tools.t1.get().getTime());
			try {
				Thread.sleep(100);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}

class ThreadB1 extends Thread{
	@Override
	public void run() {
		for (int i=0;i<20;i++) {
			if (Tools.t1.get() == null) {
				Tools.t1.set(new Date());
			}
			System.out.println("B" + Tools.t1.get().getTime());
			try {
				Thread.sleep(100);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}
           

运行结果

A1562049727699
B1562049728701
A1562049727699
B1562049728701
A1562049727699
B1562049728701
A1562049727699
B1562049728701
A1562049727699
B1562049728701
B1562049728701
B1562049728701
B1562049728701
B1562049728701
B1562049728701
B1562049728701
B1562049728701
B1562049728701

           

每个线程获取到的值是不一样的