一.在线程池中使用

  1. public class Test {
  2.     public static ThreadLocal<Integer> threadLocal = new ThreadLocal<>();
  3.     public static void main(String[] args) {
  4.         ExecutorService executorService = Executors.newFixedThreadPool(1);
  5.         executorService.execute(() -> {
  6.             threadLocal.set(20);
  7.             System.out.println(Thread.currentThread().getName() + ":" + threadLocal.get());
  8.         });
  10.         for (int i = 0; i < 10; i++) {
  11.             executorService.execute(() -> {
  12.                 System.out.println(Thread.currentThread().getName() + ":" + threadLocal.get());
  13.             });
  14.         }
  15.     }
  16. }
  18. 输出：
  19. pool-1-thread-1:20
  20. pool-1-thread-1:20
  21. pool-1-thread-1:20
  22. pool-1-thread-1:20
  23. pool-1-thread-1:20
  24. pool-1-thread-1:20
  25. pool-1-thread-1:20
  26. pool-1-thread-1:20
  27. pool-1-thread-1:20
  28. pool-1-thread-1:20
  29. pool-1-thread-1:20

1.使用后删除

  1. public class Test {
  2.     public static ThreadLocal<Integer> threadLocal = new ThreadLocal<>();
  3.     public static void main(String[] args) {
  4.         ExecutorService executorService = Executors.newFixedThreadPool(1);
  5.         executorService.execute(() -> {
  6.             threadLocal.set(20);
  7.             System.out.println(Thread.currentThread().getName() + ":" + threadLocal.get());
  8.             threadLocal.remove();
  9.         });
  11.         for (int i = 0; i < 10; i++) {
  12.             executorService.execute(() -> {
  13.                 System.out.println(Thread.currentThread().getName() + ":" + threadLocal.get());
  14.             });
  15.         }
  16.     }
  17. }
  19. 输出：
  20. pool-1-thread-1:20
  21. pool-1-thread-1:null
  22. pool-1-thread-1:null
  23. pool-1-thread-1:null
  24. pool-1-thread-1:null
  25. pool-1-thread-1:null
  26. pool-1-thread-1:null
  27. pool-1-thread-1:null
  28. pool-1-thread-1:null
  29. pool-1-thread-1:null
  30. pool-1-thread-1:null

2.线程逻辑最开始删除

  1. public class Test {
  2.     public static ThreadLocal<Integer> threadLocal = new ThreadLocal<>();
  3.     public static void main(String[] args) {
  4.         ExecutorService executorService = Executors.newFixedThreadPool(1);
  5.         executorService.execute(() -> {
  6.             threadLocal.remove();
  7.             threadLocal.set(20);
  8.             System.out.println(Thread.currentThread().getName() + ":" + threadLocal.get());
  9.         });
  11.         for (int i = 0; i < 10; i++) {
  12.             executorService.execute(() -> {
  13.                 threadLocal.remove();
  14.                 System.out.println(Thread.currentThread().getName() + ":" + threadLocal.get());
  15.             });
  16.         }
  17.     }
  18. }
  20. 输出：
  21. pool-1-thread-1:20
  22. pool-1-thread-1:null
  23. pool-1-thread-1:null
  24. pool-1-thread-1:null
  25. pool-1-thread-1:null
  26. pool-1-thread-1:null
  27. pool-1-thread-1:null
  28. pool-1-thread-1:null
  29. pool-1-thread-1:null
  30. pool-1-thread-1:null
  31. pool-1-thread-1:null