14.ThreadLocal

ThreadLocal
    1.线程局部变量,是一种多线程并发访问变量的解决方案,与同步技术 synchronize 加锁的方式不同,threadlocal完全不提供锁,而使用
       空间换时间的手段,为每个线程提供变量的独立副本,一保证现成的安全。
    2.在并发不是很高的时候,加锁的性能会更好,但是作为一套完全无关的线程安全解决方案,减少锁的竞争。
  1. package demo3;
  2. import java.util.concurrent.TimeUnit;
  3. /**
  4. * Created by liudan on 2017/7/7.
  5. */
  6. public class MyThread1 {
  7. public static ThreadLocal<String> threadLocalString = new ThreadLocal<String>();
  8. public void setThreadLocalString(String string) {
  9. threadLocalString.set(string);
  10. }
  11. public void getThreadLocalString() {
  12. System.err.println("◆:" + Thread.currentThread().getName() + ":" + threadLocalString.get());
  13. }
  14. public static void main(String[] args) {
  15. final MyThread1 myThread1 = new MyThread1();
  16. Thread t1 = new Thread(new Runnable() {
  17. @Override
  18. public void run() {
  19. myThread1.setThreadLocalString("张帅");
  20. myThread1.getThreadLocalString();
  21. }
  22. },"T0000-01");
  23. Thread t2 = new Thread(new Runnable() {
  24. @Override
  25. public void run() {
  26. try {
  27. TimeUnit.SECONDS.sleep(0);
  28. myThread1.setThreadLocalString("张帅1111");
  29. myThread1.getThreadLocalString();
  30. } catch (InterruptedException e) {
  31. e.printStackTrace();
  32. }
  33. }
  34. },"T0000-02");
  35. t1.start();
  36. t2.start();
  37. }
  38. }
  39. 输出:
  40. ◆:T0000-01:张帅 ◆:T0000-02:张帅1111



posted @ 2017-08-07 23:11  逍遥叹!!  阅读(149)  评论(0编辑  收藏  举报