如何在 Java 中檢查執行緒的優先順序

問題描述

如何檢查執行緒的優先順序？

解決方案

以下示例演示瞭如何使用執行緒的 getPriority() 方法檢查執行緒的優先順序。

public class Main extends Object {
   private static Runnable makeRunnable() {
      Runnable r = new Runnable() {
         public void run() {
            for (int i = 0; i < 5; i++) {
               Thread t = Thread.currentThread();
               System.out.println("in run() - priority = " + t.getPriority()+ ", name = " + t.getName());
               try {
                  Thread.sleep(2000);
               } catch (InterruptedException x) {}
            }
         }
      };
      return r;
   }
   public static void main(String[] args) {
      System.out.println(
         "in main() - Thread.currentThread(). getPriority() = " + Thread.currentThread().getPriority());
      System.out.println(
         "in main() - Thread.currentThread().getName() = "+ Thread.currentThread().getName());
      
      Thread threadA = new Thread(makeRunnable(), "threadA");
      threadA.start();
      try {
         Thread.sleep(3000);
      } catch (InterruptedException x) {}
      System.out.println("in main() - threadA.getPriority() = " + threadA.getPriority());
   }
}

結果

以上程式碼示例將產生以下結果。

in main() - Thread.currentThread().getPriority() = 5
in main() - Thread.currentThread().getName() = main
in run() - priority = 5, name = threadA
in run() - priority = 5, name = threadA
in main() - threadA.getPriority() = 5
in run() - priority = 5, name = threadA
in run() - priority = 5, name = threadA
in run() - priority = 5, name = threadA