从头认识java-18.2 基本的线程机制（8）多线程的异常捕捉

这一章节我们来讨论一下多线程的异常捕捉。
1.普通情况的异常

package com.ray.ch17;

public class Test {

	public static void main(String[] args) {
		try {
			new ThreadA().run();
		} catch (Exception e) {
			System.out.println("捕捉到异常");
		}
	}
}

class ThreadA implements Runnable {

	@Override
	public void run() {
		throw new RuntimeException();
	}
}

输出：
捕捉到异常

2.多线程的异常

package com.ray.ch17;

public class Test {

	public static void main(String[] args) {
		try {
			new Thread(new ThreadA()).start();
		} catch (Exception e) {
			System.out.println("捕捉到异常");
		}
	}
}

class ThreadA implements Runnable {

	@Override
	public void run() {
		throw new RuntimeException();
	}
}

输出：
Exception in thread "Thread-0" java.lang.RuntimeException
at com.ray.ch17.ThreadA.run(Test.java:18)
at java.lang.Thread.run(Thread.java:662)

3.问题：
在普通的情况下，我们可以顺利的捕捉到异常，但是如果在多线程的情况下，捕捉异常的方式其实不是上面的那种

4.解决方案
实现Thread.UncaughtExceptionHandler接口
（1）使用普通的方式来实现

package com.ray.ch17;

public class Test {

	public static void main(String[] args) {
		try {
			Thread thread = new Thread(new ThreadA());
			thread.setUncaughtExceptionHandler(new MyUncaughtExceptionHandler());
			thread.start();
		} catch (Exception e) {
			System.out.println("捕捉到异常");
		}
	}
}

class ThreadA implements Runnable {

	@Override
	public void run() {
		throw new RuntimeException();
	}
}

class MyUncaughtExceptionHandler implements Thread.UncaughtExceptionHandler {

	@Override
	public void uncaughtException(Thread t, Throwable e) {
		System.out.println("捕捉到：" + t.getName() + "的异常");
	}
}

输出：
捕捉到：Thread-0的异常

（2）使用线程池的方式来实现

package com.ray.ch17;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;

public class Test {

	public static void main(String[] args) {
		ExecutorService executorService = Executors
				.newCachedThreadPool(new MyThreadFactory());
		executorService.execute(new ThreadA());
		executorService.shutdown();
	}
}

class ThreadA implements Runnable {

	@Override
	public void run() {
		throw new RuntimeException();
	}
}

class MyUncaughtExceptionHandler implements Thread.UncaughtExceptionHandler {

	@Override
	public void uncaughtException(Thread t, Throwable e) {
		System.out.println("捕捉到：" + t.getName() + "的异常");
	}
}

class MyThreadFactory implements ThreadFactory {

	@Override
	public Thread newThread(Runnable r) {
		Thread thread = new Thread(r);
		thread.setUncaughtExceptionHandler(new MyUncaughtExceptionHandler());
		return thread;
	}
}

输出：
捕捉到：Thread-0的异常

总结：这一章节比较详细的讨论了多线程的异常捕捉。

这一章节就到这里，谢谢。
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