java线程(三)线程的6种状态

1. NEW ： 线程刚刚创建，还没有执行start启动

2. RUNNABLE ： 可运行状态，由线程调度器可以安排执行

   • 包括READY和RUNNING两种细分状态

3. WAITING： 等待被唤醒

4. TIMED WAITING： 隔一段时间后自动唤醒

5. BLOCKED： 严重被阻塞，正在等待锁（只有synchronized(操作系统调度)才会出现）

6. TERMINATED： 线程结束

   public static void main(String[] args) throws InterruptedException {
        //t1
        Thread t1 = new Thread(()->{
            //线程在执行runnable状态
            System.out.println("2: "+Thread.currentThread().getState());
            for (int i=0;i<3;i++){
                SleepHelper.sleepSeconds(1);
                System.out.println(i + " ");
            }
            System.out.println();
        });
        //线程new了，但是还没start所以是NEW
        System.out.println("1: "+t1.getState());
        t1.start();
        t1.join();//等地t1线程结束.
        //线程结束 terminated
        System.out.println("3: "+t1.getState());

        //t2
        Thread t2 = new Thread(()->{
            LockSupport.park(); //线程等待被叫醒，waiting
            System.out.println("t2 go on");
            try {
                TimeUnit.SECONDS.sleep(5);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        });
        t2.start();
        TimeUnit.SECONDS.sleep(1);
        System.out.println("4: "+t2.getState());

        LockSupport.unpark(t2); //叫醒t2线程.
        TimeUnit.SECONDS.sleep(1);
        System.out.println("5: "+t2.getState());//因为sleep 5m，所以timed_waiting


        //t3
        final Object o = new Object();
        Thread t3 = new Thread(()->{
            synchronized (o){
                System.out.println("t3 得到了锁 o");
            }
        });
        new Thread(()->{
            synchronized (o){
                SleepHelper.sleepSeconds(5);
            };
        }).start();
        SleepHelper.sleepSeconds(1);
        t3.start();
        SleepHelper.sleepSeconds(1);
        System.out.println("6: " + t3.getState());

        //只有synchronized才会进入 block 状态
        //t04
        final Lock lock = new ReentrantLock();
        Thread t4 = new Thread(()->{
            lock.lock();
            System.out.println("t4 得到了锁 lock");
            lock.unlock();
        });
        new Thread(()->{
           lock.lock();
           SleepHelper.sleepSeconds(5);
           lock.unlock();
        }).start();
        SleepHelper.sleepSeconds(1);
        t4.start();
        SleepHelper.sleepSeconds(1);
        System.out.println("7: "+t4.getState());

        //t5
        Thread t5 = new Thread(()->{
            LockSupport.park();
        });
        t5.start();
        SleepHelper.sleepSeconds(1);
        System.out.println("8: "+t5.getState());
        LockSupport.unpark(t5);
    }

结果：

"D:\Program Files\Java\jdk1.8.0_271\bin\java.exe" "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.1.1\lib\idea_rt.jar=51575:D:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.1.1\bin" -Dfile.encoding=UTF-8 -classpath "D:\Program Files\Java\jdk1.8.0_271\jre\lib\charsets.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\deploy.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\access-bridge-64.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\cldrdata.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\dnsns.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\jaccess.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\jfxrt.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\localedata.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\nashorn.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunec.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunjce_provider.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunmscapi.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunpkcs11.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\zipfs.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\javaws.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\jce.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\jfr.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\jfxswt.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\jsse.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\management-agent.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\plugin.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\resources.jar;D:\Program Files\Java\jdk1.8.0_271\jre\lib\rt.jar;E:\IdeaProject\lambda\target\classes" com.cebbank.juc.c_000_threadbasic.T04_ThreadState
1: NEW
2: RUNNABLE
0 
1 
2 

3: TERMINATED
4: WAITING
t2 go on
5: TIMED_WAITING
6: BLOCKED
7: WAITING
t3 得到了锁 o
8: WAITING
t4 得到了锁 lock

Process finished with exit code 0