Java学习，线程优先级设置

Java每个线程都有优先级，线程优先级决定了线程被调度器选中的机会。Java提供了三个常量来表示线程优先级：MIN_PRIORITY、NORM_PRIORITY 和 MAX_PRIORITY，这些常量在 Thread 类中定义。

示例1，线程设置优先级：

public class MyThread extends Thread {
    public void run() {
        for (int i = 0; i < 10; i++) {
            System.out.println(Thread.currentThread().getName() + " - Priority: " +                                               Thread.currentThread().getPriority() + " - Count: " + i);
            try {
                Thread.sleep(100); 
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
 
    public static void main(String[] args) {
        MyThread thread1 = new MyThread();
        MyThread thread2 = new MyThread();
 
        // 设置线程优先级
        thread1.setPriority(Thread.MAX_PRIORITY);
        thread2.setPriority(Thread.MIN_PRIORITY);
 
        // 启动线程
        thread1.start();
        thread2.start();
    }
}

示例2，设置线程优先级：

public class SimplePriorities extends Thread {
   private int countDown = 5;
   private volatile double d = 0; 
   public SimplePriorities(int priority) {
      setPriority(priority);
      start();
   }
   public String toString() {
      return super.toString() + ": " + countDown;
   }
   public void run() {
      while(true) {
         for(int i = 1; i < 100000; i++)
         d = d + (Math.PI + Math.E) / (double)i;
         System.out.println(this);
         if(--countDown == 0) return;
      }
   }
   public static void main(String[] args) {
      new SimplePriorities(Thread.MAX_PRIORITY);
      for(int i = 0; i < 5; i++)
      new SimplePriorities(Thread.MIN_PRIORITY);
   }
}