线程的状态

线程的状态

线程状态包括NEW、就绪状态、运行状态、TIMED_WAITING、阻塞状态和终止状态。终止后，线程无法再次启动。

以下代码演示如何打印线程的状态：

package com.cxf.multithread.state;

public class TestForState {
    public static void main(String[] args) {
        Thread thread = new Thread(()->{
            try {
                Thread.sleep(1);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            for (int i = 0; i < 5; i++) {
                System.out.println("i am running");
            }
        });
        Thread.State state = thread.getState();
        System.out.println("after create:"+state);
        thread.start();
        state = thread.getState();
        System.out.println("after start:"+state);
        while(state!=Thread.State.TERMINATED){
            state=thread.getState();
            System.out.println("when running:"+state);
        }
        System.out.println("end:"+state);
    }
}

输出结果：

after create:NEW
after start:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:RUNNABLE
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:TIMED_WAITING
when running:RUNNABLE
i am running
i am running
i am running
i am running
i am running
when running:BLOCKED
when running:TERMINATED
end:TERMINATED

此处线程创建后进入NEW状态，start后进入RUNNABLE状态，用sleep方法后进入TIMED_WAITING状态，TIMED_WAITING结束后重新进入RUNNABLE状态，RUNNABLE状态持续一段时间后开始真正的运行线程，线程有IO行为时被主线程抢走运行机会，进入阻塞状态。线程运行结束进入终止状态。