Thread Interrupt in java

问题

I have the following questions, if I interrupt a thread in java, a process that is running 15 minutes, it will stop the process, stop the methods or will finish this process,and not allow others continue in line?

I have a "thread" that will call a method that will do a comparison based "access" and "postgres" after it will insert in postgres, if I want to stop the thread that called this action, she will succeed the stop the process, or wait they finish?

回答1:

It will not stop the thread unless the methods executing in it are willing to terminate when they receive the "interrupt" signal. Methods that throw InterruptedException usually fall into this category. Of course, all methods in the call chain need to cooperate in one way or another.

If your code does not call "interruptable" methods or has sections that don't call them for long periods, then make them check flag Thread.isInterrupted() periodically, and terminate clean and gracefully if it ever becomes true. Same thing if you ever receive (and catch, which you should) InterruptedExceptions.

Your question can be improved, though, if your intent is more specific. I was about to explain how the "thread interrupt" protocol works, but perhaps this is not what you are looking for.

回答2:

When you "interrupt" a thread, it does one of three things (which are probably the same thing behind the scenes):

• If the thread is currently waiting, sleeping, or joining another thread, the interrupt will cause an InterruptedException to be thrown in the target thread.
• If the thread is blocked waiting on "interruptible I/O" (that is, operations on an implementation of InterruptibleChannel), a ClosedByInterruptException will be thrown.
• If it's not doing one of those things, then a flag will be set on the thread. The thread can check that flag by calling Thread.interrupted() (which will immediately reset the flag)...but if it doesn't, the next call to any_object.wait(), Thread.sleep(), or any_thread.join(), and perhaps certain other blocking methods, will throw an exception.

All these exceptions, of course, are checked exceptions...which almost invariably means that there will be an exception handler nearby (which, unless the code was designed to be interruptible, will typically just ignore the exception and try the operation again). And if the thread never waits, and never checks the interrupt flag, then interrupting it won't do much.

Also, if the thread is currently waiting on something outside the control of the JVM, the interrupt might not have any effect. On some platforms (Windows comes to mind), Java has a hard time interrupting native code.

All those caveats can be summed up as: If what you want is to kill off an unruly thread, this probably isn't the way to do it. Truth is, there isn't a decent way to kill a thread without leaving your process in a potentially wacky state. What you typically want in such cases is a separate process you can kill if it gets out of hand.

回答3:

From the source:-

An interrupt is an indication to a thread that it should stop what it is doing and do something else. It's up to the programmer to decide exactly how a thread responds to an interrupt, but it is very common for the thread to terminate. This is the usage emphasized in this lesson. A thread sends an interrupt by invoking interrupt on the Thread object for the thread to be interrupted. For the interrupt mechanism to work correctly, the interrupted thread must support its own interruption.

来源：https://stackoverflow.com/questions/18410502/thread-interrupt-in-java