Threadlocal使用Case

Threadlocal能够为每个线程分配一份单独的副本，使的线程与线程之间能够独立的访问各自副本。Threadlocal 内部维护一个Map，key为线程的名字，value为对应操作的副本。

/**
 * Created by majun on 16/3/23.
 */
public class ThreadLocalTest {
    /*
    Threadlocal为每个线程维护一个单独的副本, 线程之间互不影响
     */
    private ThreadLocal<Integer> threadLocal = new ThreadLocal<Integer>() {
        @Override
        protected Integer initialValue() {
            return 0;
        }
    };

    //获取下一个序列值
    public int getNextNum() {
        threadLocal.set(threadLocal.get() + 1);
        return threadLocal.get();
    }

    /*
     */
    public static void main(String[] args) {
        ThreadLocalTest threadLocalTest = new ThreadLocalTest();
        Client client1 = new Client(threadLocalTest);
        Client client2 = new Client(threadLocalTest);
        Client client3 = new Client(threadLocalTest);

        Thread thread1 = new Thread(client1);
        Thread thread2 = new Thread(client2);
        Thread thread3 = new Thread(client3);

        thread1.start();
        thread2.start();
        thread3.start();

    }

    static class Client implements Runnable {
        private ThreadLocalTest threadLocalTest;

        public Client(ThreadLocalTest threadLocalTest) {
            this.threadLocalTest = threadLocalTest;
        }
        public void run() {
            for (int i = 0; i < 3; i++) {
                System.out.println("thread[" + Thread.currentThread().getName() + "] --> nextNumber=[" +
                        threadLocalTest.getNextNum() + "]");
            }
        }
    }
}