[置顶] Java 多线程 学习笔记（二）停止线程的几种方法

1.异常法：

package test;

import exthread.MyThread;

import exthread.MyThread;

public class Run {

public static void main(String[] args) {
try {
MyThread thread = new MyThread();
thread.start();
Thread.sleep(2000);
thread.interrupt();
} catch (InterruptedException e) {
System.out.println("main catch");
e.printStackTrace();
}
System.out.println("end!");
}

}

package exthread;

public class MyThread extends Thread {
<span style="white-space:pre">	</span>@Override
<span style="white-space:pre">	</span>public void run() {
<span style="white-space:pre">		</span>super.run();
<span style="white-space:pre">		</span>for (int i = 0; i < 500000; i++) {
<span style="white-space:pre">			</span>if (this.interrupted()) {
<span style="white-space:pre">				</span>System.out.println("已经是停止状态了!我要退出了!");
<span style="white-space:pre">				</span>break;
<span style="white-space:pre">			</span>}
<span style="white-space:pre">			</span>System.out.println("i=" + (i + 1));
<span style="white-space:pre">		</span>}
<span style="white-space:pre">		</span>System.out.println("我被输出，如果此代码是for又继续运行，线程并未停止！");
<span style="white-space:pre">	</span>}
}

运行结果：

......

i=255229

i=255230

i=255231

i=255232

i=255233

i=255234

i=255235

i=255236

i=255237

i=255238

i=255239

i=255240

i=255241

i=255242

i=255243

i=255244

i=255245

i=255246

i=255247

i=255248

i=255249

i=255250

i=255251

i=255252

i=255253

i=255254

i=255255

i=255256

i=255257

i=255258

i=255259

i=255260

i=255261

i=255262

i=255263

i=255264

i=255265

i=255266

已经是停止状态了!我要退出了!

end!

我被输出，如果此代码是for又继续运行，线程并未停止！

已经是停止状态了!我要退出了!    虽然停止，但是for循环以后的代码还是会执行的

正确的退出方式

package exthread;

public class MyThread extends Thread {
@Override
public void run() {
super.run();
try {
for (int i = 0; i < 500000; i++) {
if (this.interrupted()) {
System.out.println("已经是停止状态了!我要退出了!");
throw new InterruptedException();
}
System.out.println("i=" + (i + 1));
}
System.out.println("我在for下面");
} catch (InterruptedException e) {
System.out.println("进MyThread.java类run方法中的catch了！");
e.printStackTrace();
}
}
}

2.在沉睡中停止

package exthread;

public class MyThread extends Thread {
@Override
public void run() {
super.run();
try {
System.out.println("run begin");
Thread.sleep(200000);
System.out.println("run end");
} catch (InterruptedException e) {
System.out.println("在沉睡中被停止!进入catch!"+this.isInterrupted());
e.printStackTrace();
}
}
}

package test;

import exthread.MyThread;

import exthread.MyThread;

public class Run {

public static void main(String[] args) {
try {
MyThread thread = new MyThread();
thread.start();
Thread.sleep(200);
thread.interrupt();
} catch (InterruptedException e) {
System.out.println("main catch");
e.printStackTrace();
}
System.out.println("end!");
}

}

运行结果：

run begin

end!

在沉睡中被停止!进入catch!false

java.lang.InterruptedException: sleep interrupted
at java.lang.Thread.sleep(Native Method)
at exthread.MyThread.run(MyThread.java:9)

另外一种情况是先停止后sleep 

3.暴力停止： 

Thread.stop() 这种方法存在非线程安全问题。所以暂时不考虑

4.使用return 停止线程

package test.run;

import extthread.MyThread;

public class Run {

public static void main(String[] args) throws InterruptedException {
MyThread t=new MyThread();
t.start();
Thread.sleep(2000);
t.interrupt();
}

}

package extthread;

public class MyThread extends Thread {

@Override
public void run() {
while (true) {
if (this.isInterrupted()) {
System.out.println("停止了!");
return;
}
System.out.println("timer=" + System.currentTimeMillis());
}
}

}