• 有哪6種狀態？
• 每個狀態是什么含義
• 狀態間的轉化圖示
• 阻塞狀態是什么

每個狀態是什么含義

• New
• Runnable
• Blocked
• Waiting
• Timed Waiting
• Terminated

http://www.lxweimin.com/p/dfdc150a3e54

image.png

展示線程的NEW、RUNNABLE、Terminated狀態

/**
 * 描述：     展示線程的NEW、RUNNABLE、Terminated狀態。即使是正在運行，也是Runnable狀態，而不是Running。
 */
public class NewRunnableTerminated implements Runnable {

    public static void main(String[] args) {
        Thread thread = new Thread(new NewRunnableTerminated());
        //打印出NEW的狀態
        System.out.println(thread.getState());
        thread.start();
        System.out.println(thread.getState());
        try {
            Thread.sleep(6);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //打印出RUNNABLE的狀態，即使是正在運行，也是RUNNABLE，而不是RUNNING
        System.out.println(thread.getState());
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //打印出TERMINATED狀態
        System.out.println(thread.getState());
    }

    @Override
    public void run() {
        for (int i = 0; i < 1000; i++) {
            System.out.println(i);
        }
    }
}

NEW
RUNNABLE
0
1
2
... 省略
294
295
RUNNABLE
296
297
298
... 省略
998
999
TERMINATED

Process finished with exit code 0

展示Blocked, Waiting, TimedWaiting

/**
 * 描述：     展示Blocked, Waiting, TimedWaiting
 */
public class BlockedWaitingTimedWaiting implements Runnable{
    public static void main(String[] args) {
        BlockedWaitingTimedWaiting runnable = new BlockedWaitingTimedWaiting();
        Thread thread1 = new Thread(runnable);
        thread1.start();

        try {
            Thread.sleep(5);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        Thread thread2 = new Thread(runnable);
        thread2.start();

        //打印出Timed_Waiting狀態，因為正在執行Thread.sleep(1000);
        System.out.println(thread1.getState());
        //打印出BLOCKED狀態，因為thread2想拿得到sync()的鎖卻拿不到
        System.out.println(thread2.getState());
        try {
            Thread.sleep(1300);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //打印出WAITING狀態，因為執行了wait()
        System.out.println(thread1.getState());

    }

    @Override
    public void run() {
        syn();
    }

    private synchronized void syn() {
        try {
            Thread.sleep(1000);
            wait();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

TIMED_WAITING
BLOCKED
WAITING

阻塞狀態

一般習慣而言，把Blocked（被阻塞）、Waiting（等待）、Timed_waiting（即使等待）都成為阻塞狀態

• 不僅僅是Blocked

特別感謝

悟空