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线程的状态|生命周期(通过代码案例简单而深入的理解线程的状态)


文章目录

  • ​​线程的生命周期/状态state​​
  • ​​线程状态变化流程图​​
  • ​​线程状态​​
  • ​​NEW​​
  • ​​案例举例​​
  • ​​控台输出​​
  • ​​RUNNABLE和RUNNING​​
  • ​​案例举例​​
  • ​​控台输出​​
  • ​​备注说明​​
  • ​​TIMED_WAITING​​
  • ​​案例举例​​
  • ​​控台输出​​
  • ​​备注说明​​
  • ​​WAITING​​
  • ​​案例举例​​
  • ​​控台输出​​
  • ​​备注说明​​
  • ​​Blocked​​
  • ​​案例举例​​
  • ​​控台说明​​
  • ​​TERMINATED​​

线程的生命周期/状态state

线程状态变化流程图

线程的状态|生命周期(通过代码案例简单而深入的理解线程的状态)_java

线程状态

NEW

案例举例

package com.gaoxinfu.demo.jdk.rt.java.lang.thread.status;

/**
* @Description:
* @Author: gaoxinfu
* @Date: 2020-06-11 11:48
*/
public class NewStatus {

public static void main(String[] args) {
Thread thread=new Thread("thread-a");
System.out.println("当前线程状态 = "+thread.getState());
}
}

控台输出

当前线程状态 = NEW

Process finished with exit code 0

RUNNABLE和RUNNING

案例举例

创建一个带有线程处理逻辑的线程类StatusThreadDemo

package com.gaoxinfu.demo.jdk.rt.java.lang.thread.status;

import java.util.concurrent.TimeUnit;

/**
* @Description:
* @Author: gaoxinfu
* @Date: 2020-06-10 16:37
*/
public class StartStatus {

public static void main(String[] args) {
StatusThreadDemo thread=new StatusThreadDemo();
System.out.println("start前线程状态 = "+thread.getState());
thread.start();
System.out.println("start后线程状态 = "+thread.getState());
try {
thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("start后线程正在运行的状态 = "+thread.getState());


}
}

class StatusThreadDemo extends Thread{
@Override
public void run() {
for (int i=0;i<5;i++){
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("StatusThreadDemo i="+i);
}
}
}

控台输出

start前线程状态 = NEW
start后线程状态 = RUNNABLE
StatusThreadDemo i=0
StatusThreadDemo i=1
StatusThreadDemo i=2
StatusThreadDemo i=3
StatusThreadDemo i=4

Process finished with exit code 0

备注说明

1.这里注意下,start()方法调用成功之后,并不是立刻进行运行,而是状态由New转为Runnable状态
而后,由操作系统进行调度转为Running运行状态;
2.这里大家需要注意下:Running状态如果由于某种原因被阻塞(如sleep中)或者由于某些原因,指令无法运行,
那么状态也会转为Runnable,等待操作系统重新调度;
3.这里的操作系统的切换,实际上就是CPU在线程中的调度切换;
4.我们上面演示的“start后线程状态 =”不一定是RUNNABLE 也有可能刚好碰上代码在sleep 就是Timed Wating

TIMED_WAITING

主要是你在调用下面方法的时候,待了超时时间

join
sleep
wait
LockSupport.parkUnit

案例举例

package com.gaoxinfu.demo.jdk.rt.java.lang.thread.status;

import java.util.concurrent.TimeUnit;

/**
* @Description:
* @Author: gaoxinfu
* @Date: 2020-06-11 15:25
*/
public class TimedWaitingStatus {

public static void main(String[] args) {
Thread thread=new Thread(new TimedWaitingThreadDemo());
thread.start();
System.out.println("线程sleep中的当前状态 = "+thread.getState());
}
}



class TimedWaitingThreadDemo implements Runnable{

@Override
public void run() {
System.out.println("开始sleep(5s)方法的调用");
try {
TimeUnit.SECONDS.sleep(5);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("结束sleep(5s)方法的调用");

}
}

控台输出

Connected to the target VM, address: '127.0.0.1:65084', transport: 'socket'
开始sleep(5s)方法的调用
线程sleep中的当前状态 = TIMED_WAITING
结束sleep(5s)方法的调用
Disconnected from the target VM, address: '127.0.0.1:65084', transport: 'socket'

Process finished with exit code 0

备注说明

WAITING

join
wait
LockSupport.parkUnit

1.上面的方法调用的时候,不带超时时间

案例举例

package com.gaoxinfu.demo.jdk.rt.java.lang.thread.status;

import java.util.concurrent.TimeUnit;

/**
* @Description:
* @Author: gaoxinfu
* @Date: 2020-06-11 15:36
*/
public class WaitingStatus {
public static void main(String[] args) throws InterruptedException {

Thread thread1=new Thread(new WaitingThreadDemo(),"thread1");
thread1.start();
System.out.println(thread1.getState());
}
}

class WaitingThreadDemo implements Runnable{

@Override
public void run() {
try {
Thread.currentThread().join();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("Hello 大家好,我是WaitingThreadDemo ="+Thread.currentThread().getName());
}
}

控台输出

WAITING

Process finished with exit code 130 (interrupted by signal 2: SIGINT)

备注说明

Blocked

1.Blocked阻塞状态是一种锁阻塞的状态;
synchronized的锁

案例举例

package com.gaoxinfu.demo.jdk.rt.java.lang.thread.status;

/**
* @Description:
* @Author: gaoxinfu
* @Date: 2020-06-11 16:04
*/
public class BlockedStatus {


public static void main(String[] args) {

Thread thread1=new Thread(new BlockedThreadDemo(),"thread1");
Thread thread2=new Thread(new BlockedThreadDemo(),"thread1");
thread1.start();
thread2.start();
System.out.println("thread1线程状态 = " +thread1.getState());
System.out.println("thread2线程状态 = " +thread2.getState());

}
}

class BlockedThreadDemo implements Runnable{

@Override
public void run() {
synchronized (this){
try {
System.out.println("当前线程名字 = "+Thread.currentThread().getName()+",开始锁定代码执行片段");
Thread.currentThread().sleep(5000);
System.out.println("当前线程名字 = "+Thread.currentThread().getName()+",结束锁定代码执行片段");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}

控台说明

当前线程名字 = thread1,开始锁定代码执行片段
thread1线程状态 = TIMED_WAITING
thread2线程状态 = BLOCKED
当前线程名字 = thread1,开始锁定代码执行片段
当前线程名字 = thread1,结束锁定代码执行片段
当前线程名字 = thread1,结束锁定代码执行片段

Process finished with exit code 0

TERMINATED

1.线程终止状态,也就是线程任务结束时的一个状态


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