并发编程实战 1.10. 线程组处理异常 - 重写uncaughtException()

摘要: 线程组通过重写uncaughtException(Thread t, Throwable e)方法处理线程组异常

线程组通过重写uncaughtException(Thread t, Throwable e)方法处理线程组异常。

范例： 查询文件（sleep），其中一个抛出异常，threadGroup处理异常后，全部进程都interrupt

自定义的线程组：

package com.rr.concurrent.chapter1.recipe11.test;

/**
* Created by isaac_gu on 2016/5/11.
*/
public class MyThreadGroup extends ThreadGroup {
public MyThreadGroup(String name) {
super(name);
}

@Override
public void uncaughtException(Thread t, Throwable e) {
System.out.println("******************************** Exception Handler ******************************");

System.out.printf("1. %s 线程出现了异常！\n", t.getName());
System.out.printf("2. Exception: %s: %s\n", e.getClass().getName(), e.getMessage());
System.out.printf("3. Stack Trace: \n");
e.printStackTrace(System.out);
System.out.printf("4. Thread status: %s\n", t.getState());
System.out.println("******************************** Exception Handler END ******************************");

//打断所有活动的线程
interrupt();
}
}

查找线程：

package com.rr.concurrent.chapter1.recipe11.test;

import java.util.Random;
import java.util.concurrent.TimeUnit;

/**
* Created by isaac_gu on 2016/5/11.
*/
public class SearchTask implements Runnable {
@Override
public void run() {
System.out.printf("%s 线程开始查找！\n", Thread.currentThread().getName());
//2秒后开始查找
suspend(2);
while (true) {
//当除以0 的时候报异常
int c = 1000 / new Random().nextInt(100);
if (Thread.currentThread().isInterrupted()) {
System.out.printf("%s 被打断！\n", Thread.currentThread().getName());
return;
}

//每100微秒查询一次
try {
TimeUnit.MILLISECONDS.sleep(100);
} catch (InterruptedException e) {
System.out.printf("%s 被打断！\n", Thread.currentThread().getName());
return;
}
}
}

private void suspend(int s) {
try {
TimeUnit.SECONDS.sleep(s);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

测试：

package com.rr.concurrent.chapter1.recipe11.test;

/**
* Created by isaac_gu on 2016/5/11.
* 范例： 查询文件，其中一个抛出异常，threadGroup处理异常后，全部进程都interrupt
*/
public class Test {
public static void main(String[] args) {
MyThreadGroup myThreadGroup = new MyThreadGroup("myThreadGroup");
SearchTask searchTask = new SearchTask();

for (int i = 0, len = 10; i < len; i++) {
new Thread(myThreadGroup, searchTask).start();
}

System.out.println("主线程结束！");
}
}

运行结果：

Thread-0 线程开始查找！
Thread-5 线程开始查找！
Thread-9 线程开始查找！
Thread-1 线程开始查找！
Thread-7 线程开始查找！
Thread-3 线程开始查找！
Thread-8 线程开始查找！
Thread-4 线程开始查找！
Thread-6 线程开始查找！
Thread-2 线程开始查找！
******************************** Exception Handler ******************************
1. Thread-0 线程出现了异常！
2. Exception: java.lang.ArithmeticException: / by zero
3. Stack Trace:
java.lang.ArithmeticException: / by zero
at com.rr.concurrent.chapter1.recipe11.test.SearchTask.run(SearchTask.java:17)
at java.lang.Thread.run(Thread.java:745)
4. Thread status: RUNNABLE
******************************** Exception Handler END ******************************
Thread-6 被打断！
Thread-9 被打断！
Thread-1 被打断！
Thread-3 被打断！
Thread-5 被打断！
Thread-2 被打断！
Thread-4 被打断！
Thread-7 被打断！
Thread-8 被打断！