1.7.2判断线程是否是停止状态

判断线程是否停止的状态

Thread.java类里面提供了两种方法。

1）this.interrupted()：测试当前线程是否已经中断

2）this.isInterrupted():测试线程是否已经中断

测试如下

package com.cky.thread;

/**
 * Created by edison on 2017/11/28.
 */
public class MyThread11 extends  Thread{
    @Override
    public void run() {
        super.run();
        for (int i = 0; i < 50000; i++) {
            System.out.println("i="+i);
        }
    }
}

package com.cky.test;

import com.cky.thread.MyThread11;

/**
 * Created by edison on 2017/11/28.
 */
public class Test18 {
    public static void main(String[] args) {
        try {
            MyThread11 th = new MyThread11();
            th.start();
            Thread.sleep(2000);
            th.interrupt();
            System.out.println("是否停止1="+ th.isInterrupted());
           System.out.println("是否停止2="+ th.isInterrupted());
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

i=49990
i=49991
i=49992
i=49993
i=49994
i=49995
i=49996
i=49997
i=49998
i=49999
是否停止1=false
是否停止2=false

结果分析：

结果表面当前线程并未停止，因为这个当前线程是main线程，所以打印了两个false.

测试

package com.cky.test;

/**
 * Created by edison on 2017/11/28.
 */
public class Test19 {
    public static void main(String[] args) {
        Thread.currentThread().interrupt();
        System.out.println("是否停止1="+Thread.interrupted());
        System.out.println("是否停止2="+Thread.interrupted());
        System.out.println("end");

    }
}

C:itsoftjdkinjava -Didea.launcher.port=7534 "-Didea.launcher.bin.path=C:itsoftideaIntelliJ IDEA 2016.3.3in" -Dfile.encoding=UTF-8 -classpath "C:itsoftjdkjrelibcharsets.jar;C:itsoftjdkjrelibdeploy.jar;C:itsoftjdkjrelibextaccess-bridge-32.jar;C:itsoftjdkjrelibextcldrdata.jar;C:itsoftjdkjrelibextdnsns.jar;C:itsoftjdkjrelibextjaccess.jar;C:itsoftjdkjrelibextjfxrt.jar;C:itsoftjdkjrelibextlocaledata.jar;C:itsoftjdkjrelibext
ashorn.jar;C:itsoftjdkjrelibextsunec.jar;C:itsoftjdkjrelibextsunjce_provider.jar;C:itsoftjdkjrelibextsunmscapi.jar;C:itsoftjdkjrelibextsunpkcs11.jar;C:itsoftjdkjrelibextzipfs.jar;C:itsoftjdkjrelibjavaws.jar;C:itsoftjdkjrelibjce.jar;C:itsoftjdkjrelibjfr.jar;C:itsoftjdkjrelibjfxswt.jar;C:itsoftjdkjrelibjsse.jar;C:itsoftjdkjrelibmanagement-agent.jar;C:itsoftjdkjrelibplugin.jar;C:itsoftjdkjrelib
esources.jar;C:itsoftjdkjrelib
t.jar;C:多线程核心技术第一章outproduction第一章;C:itsoftideaIntelliJ IDEA 2016.3.3libidea_rt.jar" com.intellij.rt.execution.application.AppMain com.cky.test.Test19
是否停止1=true
是否停止2=false
end

Process finished with exit code 0

结果分析：上面结果第一次判断为true,说明当前main线程已经中断，但是第二次调用变成了false.

官方文档解释：线程的中断状态由该方法清除，所以两次调用的话，第二次会返回false.

再来测试isInterrupted()

package com.cky.test;

/**
 * Created by edison on 2017/11/28.
 */
public class Test19 {
    public static void main(String[] args) {
        Thread.currentThread().interrupt();
        System.out.println("是否停止1="+Thread.currentThread().isInterrupted());
        System.out.println("是否停止2="+Thread.currentThread().isInterrupted());
        System.out.println("end");

    }
}

C:itsoftjdkinjava -Didea.launcher.port=7541 "-Didea.launcher.bin.path=C:itsoftideaIntelliJ IDEA 2016.3.3in" -Dfile.encoding=UTF-8 -classpath "C:itsoftjdkjrelibcharsets.jar;C:itsoftjdkjrelibdeploy.jar;C:itsoftjdkjrelibextaccess-bridge-32.jar;C:itsoftjdkjrelibextcldrdata.jar;C:itsoftjdkjrelibextdnsns.jar;C:itsoftjdkjrelibextjaccess.jar;C:itsoftjdkjrelibextjfxrt.jar;C:itsoftjdkjrelibextlocaledata.jar;C:itsoftjdkjrelibext
ashorn.jar;C:itsoftjdkjrelibextsunec.jar;C:itsoftjdkjrelibextsunjce_provider.jar;C:itsoftjdkjrelibextsunmscapi.jar;C:itsoftjdkjrelibextsunpkcs11.jar;C:itsoftjdkjrelibextzipfs.jar;C:itsoftjdkjrelibjavaws.jar;C:itsoftjdkjrelibjce.jar;C:itsoftjdkjrelibjfr.jar;C:itsoftjdkjrelibjfxswt.jar;C:itsoftjdkjrelibjsse.jar;C:itsoftjdkjrelibmanagement-agent.jar;C:itsoftjdkjrelibplugin.jar;C:itsoftjdkjrelib
esources.jar;C:itsoftjdkjrelib
t.jar;C:多线程核心技术第一章outproduction第一章;C:itsoftideaIntelliJ IDEA 2016.3.3libidea_rt.jar" com.intellij.rt.execution.application.AppMain com.cky.test.Test19
是否停止1=true
是否停止2=true
end

Process finished with exit code 0

结果分析：

方法isInterrupted()并未清除状态标识，所以打印了两个false.