ThreadLocal原理

╰半夏微凉° 2021-09-18 07:50 318阅读 0赞

它会为每个线程设置不同的变量副本。

[Java并发编程：深入剖析ThreadLocal][Java_ThreadLocal]

package com.zpc.tet.SchedulTest;
    
    import lombok.Synchronized;
    
    /**
     * @Author timor
     * @Date 2019/2/26
     */
    public class Test {
        ThreadLocal<Long> longLocal = new ThreadLocal<Long>();
        ThreadLocal<String> stringLocal = new ThreadLocal<String>();
    
    
        public void set() {
            longLocal.set(Thread.currentThread().getId());
            stringLocal.set(Thread.currentThread().getName());
        }
    
        public long getLong() {
            return longLocal.get();
        }
    
        public String getString() {
            return stringLocal.get();
        }
    
        public static void main(String[] args) throws InterruptedException {
            final Test test = new Test();
    
    
            test.set();
            System.out.println(test.getLong());
            System.out.println(test.getString());
    
    
            Thread thread1 = new Thread(){
                public void run() {
                    test.set();
                    System.out.println("test.getLong1():"+test.getLong());
                    System.out.println("test.getString1():"+test.getString());
                };
            };
            Thread thread2 = new Thread(){
                public void run() {
                    test.set();
                    System.out.println("test.getLong2():"+test.getLong());
                    System.out.println("test.getString2():"+test.getString());
                };
            };
            thread1.start();
            thread2.start();
            thread1.join();
            thread2.join();
    
            System.out.println(test.getLong());
            System.out.println(test.getString());
        }
    }

输出

1
    main
    test.getLong1():12
    test.getLong2():13
    test.getString1():Thread-0
    test.getString2():Thread-1
    1
    main

[Java_ThreadLocal]: https://www.cnblogs.com/dolphin0520/p/3920407.html