java - ScheduledExecutorService 的 ThreadLocal

Question

有人可以告诉我为什么当我使用 ScheduledExecutorService 启动线程时 threadlocal.get() 给我 null 吗？

 public class ThreadTest extends ParentClassThread
  {
    private static ScheduledFuture<?> periodicFuture;
    private static ScheduledExecutorService ex;

    public ThreadTest(){
        ex = Executors.newSingleThreadScheduledExecutor();
        periodicFuture = ex.schedule(this, 1, TimeUnit.SECONDS);
    }

    @Override
    public void run() {
       try {
            System.out.println("Thread started");
            for (int i = 0; i <= 100000; i++) {
                System.out.println(i);
            }
            ThreadLocal local = new ThreadLocal();
            System.out.println(local.get());
        }catch(Exception e){

        }finally {
            ex.shutdown();
        }

      }
   }

Answer 1

ThreadLocal<String> local = new ThreadLocal<String>();
local.set("String");
System.out.println(local.get());

您需要在 ThreadLocalVariable 中设置一些内容，然后检索它。最初，ThreadLocal 是空的。