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This article mainly introduces the example analysis of UncaughtExceptionHandler, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

Thread's run method does not throw any checked exception, but it may be terminated by an exception itself, resulting in the termination of the thread. The most troublesome thing is that exceptions thrown in a thread cannot be intercepted even using try...catch, which may lead to some problems, such as not being able to reclaim some system resources in the event of an exception, or not closing the current connection.

Prior to JDK5.0, you cannot set UncaughtExceptionHandler for a separate Thread, nor can you specify a default UncaughtExceptionHandler. In order to set a UncaughtExceptionHandler, you need to inherit the ThreadGroup and override the uncaughtException method.

In JDK5.0, we can set a UncaughtExceptionHandler for any Thread through the instance method setUncaughtExceptionHandler of Thread. Of course, you can also set a default UncaughtExceptionHandler for all Thread by calling the Thread.setDefaultUncaughtExceptionHandler (Thread.UncaughtExceptionHandler eh) method, which is a static method of Thread.

Define a Handler class that must implement the void uncaughtException (Thread t, Throwable e) method of the Thread.UncaughtExceptionHandler interface. If you do not set a Handler, then the Handler of a single Thread is null. However, if the single thread is a Thread in ThreadGroup, then the thread will use ThreadGroup's UncaughtExceptionHandler. ThreadGroup itself has implemented the Thread.UncaughtExceptionHandler interface.

UncaughtException (Thread a, Throwable e) can get Thread, so releasing related resources in uncaughtException is the best way.

In a word, Thread and its related auxiliary functions in JDK5.0 have been strengthened, providing us with many convenient and safe solutions.

The following is an example of UncaughtExceptionHandler, which you can run to see

Public class UncaughtExceptionHandlerSample {

Public static void main (String [] args) {

/ / the difference between comments and no comments

Thread.setDefaultUncaughtExceptionHandler (new DefaultUncaughtExceptionHandler ())

UncaughtThread a = new UncaughtThread ()

A.start ()

}

}

/ * *

* A custom UncaughtExceptionHandler

, /

Class DefaultUncaughtExceptionHandler implements Thread.UncaughtExceptionHandler {

/ * *

* any exception handling can be done here, such as logging, etc.

, /

Public void uncaughtException (Thread thread, Throwable e) {

If (e! = null & & e instanceof Error) {

If (e instanceof OutOfMemoryError) {

Try {

System.err.println ("Halting due to Out Of Memory Error..." + Thread.currentThread (). GetName ())

} catch (Throwable err) {

/ / Again we don't want to exit because of logging issues.

}

Runtime.getRuntime () .halt (- 1)

} else {

/ / Running in daemon mode, we would pass Error to calling thread.

}

} else {

System.out.println ("An exception has been capturedn")

System.out.println ("Thread:" + thread.getId ())

System.out.println ("Exception:" + e.getClass () .getName () + ":" + e.getMessage ())

System.out.println ("Thread status:" + thread.getState ())

System.out.printf ("Stack Trace: n")

E.printStackTrace (System.out)

New Thread (new UncaughtThread (). Start ()

}

}

}

/ * *

* Test thread

, /

Class UncaughtThread extends Thread {

Public void run () {

System.out.println (Integer.parseInt ("1"))

System.out.println (Integer.parseInt ("2"))

System.out.println (Integer.parseInt ("3"))

System.out.println (Integer.parseInt ("abc"))

}

} Thank you for reading this article carefully. I hope the article "sample Analysis of UncaughtExceptionHandler" shared by the editor will be helpful to you. At the same time, I also hope that you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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