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);
        }
    }
}

 1 package com.cky.test;
 2
 3 import com.cky.thread.MyThread11;
 4
 5 /**
 6  * Created by edison on 2017/11/28.
 7  */
 8 public class Test18 {
 9     public static void main(String[] args) {
10         try {
11             MyThread11 th = new MyThread11();
12             th.start();
13             Thread.sleep(2000);
14             th.interrupt();
15             System.out.println("是否停止1="+ th.isInterrupted());
16            System.out.println("是否停止2="+ th.isInterrupted());
17         } catch (InterruptedException e) {
18             e.printStackTrace();
19         }
20     }
21 }

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

 1 package com.cky.test;
 2
 3 /**
 4  * Created by edison on 2017/11/28.
 5  */
 6 public class Test19 {
 7     public static void main(String[] args) {
 8         Thread.currentThread().interrupt();
 9         System.out.println("是否停止1="+Thread.interrupted());
10         System.out.println("是否停止2="+Thread.interrupted());
11         System.out.println("end");
12
13     }
14 }

1 C:\itsoft\jdk\bin\java -Didea.launcher.port=7534 "-Didea.launcher.bin.path=C:\itsoft\idea\IntelliJ IDEA 2016.3.3\bin" -Dfile.encoding=UTF-8 -classpath "C:\itsoft\jdk\jre\lib\charsets.jar;C:\itsoft\jdk\jre\lib\deploy.jar;C:\itsoft\jdk\jre\lib\ext\access-bridge-32.jar;C:\itsoft\jdk\jre\lib\ext\cldrdata.jar;C:\itsoft\jdk\jre\lib\ext\dnsns.jar;C:\itsoft\jdk\jre\lib\ext\jaccess.jar;C:\itsoft\jdk\jre\lib\ext\jfxrt.jar;C:\itsoft\jdk\jre\lib\ext\localedata.jar;C:\itsoft\jdk\jre\lib\ext\nashorn.jar;C:\itsoft\jdk\jre\lib\ext\sunec.jar;C:\itsoft\jdk\jre\lib\ext\sunjce_provider.jar;C:\itsoft\jdk\jre\lib\ext\sunmscapi.jar;C:\itsoft\jdk\jre\lib\ext\sunpkcs11.jar;C:\itsoft\jdk\jre\lib\ext\zipfs.jar;C:\itsoft\jdk\jre\lib\javaws.jar;C:\itsoft\jdk\jre\lib\jce.jar;C:\itsoft\jdk\jre\lib\jfr.jar;C:\itsoft\jdk\jre\lib\jfxswt.jar;C:\itsoft\jdk\jre\lib\jsse.jar;C:\itsoft\jdk\jre\lib\management-agent.jar;C:\itsoft\jdk\jre\lib\plugin.jar;C:\itsoft\jdk\jre\lib\resources.jar;C:\itsoft\jdk\jre\lib\rt.jar;C:\多线程核心技术\第一章\out\production\第一章;C:\itsoft\idea\IntelliJ IDEA 2016.3.3\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain com.cky.test.Test19
2 是否停止1=true
3 是否停止2=false
4 end
5
6 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()

 1 package com.cky.test;
 2
 3 /**
 4  * Created by edison on 2017/11/28.
 5  */
 6 public class Test19 {
 7     public static void main(String[] args) {
 8         Thread.currentThread().interrupt();
 9         System.out.println("是否停止1="+Thread.currentThread().isInterrupted());
10         System.out.println("是否停止2="+Thread.currentThread().isInterrupted());
11         System.out.println("end");
12
13     }
14 }

C:\itsoft\jdk\bin\java -Didea.launcher.port=7541 "-Didea.launcher.bin.path=C:\itsoft\idea\IntelliJ IDEA 2016.3.3\bin" -Dfile.encoding=UTF-8 -classpath "C:\itsoft\jdk\jre\lib\charsets.jar;C:\itsoft\jdk\jre\lib\deploy.jar;C:\itsoft\jdk\jre\lib\ext\access-bridge-32.jar;C:\itsoft\jdk\jre\lib\ext\cldrdata.jar;C:\itsoft\jdk\jre\lib\ext\dnsns.jar;C:\itsoft\jdk\jre\lib\ext\jaccess.jar;C:\itsoft\jdk\jre\lib\ext\jfxrt.jar;C:\itsoft\jdk\jre\lib\ext\localedata.jar;C:\itsoft\jdk\jre\lib\ext\nashorn.jar;C:\itsoft\jdk\jre\lib\ext\sunec.jar;C:\itsoft\jdk\jre\lib\ext\sunjce_provider.jar;C:\itsoft\jdk\jre\lib\ext\sunmscapi.jar;C:\itsoft\jdk\jre\lib\ext\sunpkcs11.jar;C:\itsoft\jdk\jre\lib\ext\zipfs.jar;C:\itsoft\jdk\jre\lib\javaws.jar;C:\itsoft\jdk\jre\lib\jce.jar;C:\itsoft\jdk\jre\lib\jfr.jar;C:\itsoft\jdk\jre\lib\jfxswt.jar;C:\itsoft\jdk\jre\lib\jsse.jar;C:\itsoft\jdk\jre\lib\management-agent.jar;C:\itsoft\jdk\jre\lib\plugin.jar;C:\itsoft\jdk\jre\lib\resources.jar;C:\itsoft\jdk\jre\lib\rt.jar;C:\多线程核心技术\第一章\out\production\第一章;C:\itsoft\idea\IntelliJ IDEA 2016.3.3\lib\idea_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.