关于java线程生命周期

Question

So I have a "tricky" question, I want to see people opinions.

I'm programming a component, which extends a JPanel and do some custom stuff. Inside that component I have a Thread, which loops forever like this:

//chat thread
    Thread chat_thread = new Thread(new Runnable(){
        public void run(){
            while(true){
                //get chat updates
            }
        }
    });
    chat_thread.start();

So the question is, when the component is removed from its parent by the remove() method, is this thread still alive, or does it die when you remove the component?

EDIT:
Thanks all for your replies, indeed the thread does not terminate removing its starter, so in order to terminate this thread from another component, I did the following:

Set<Thread> t = Thread.getAllStackTraces().keySet();
    Iterator it = t.iterator();
    while(it.hasNext()){
        Thread t2 = (Thread)it.next();
        if(t2.getName().equals("chat_thread")){
            t2.interrupt();
        }
    }

by first creating a name for my thread with the Thread.setName() method. Thanks!

Answer 1

This thread will never die (unless it crashes or terminates itself).

Does not matter what happens to the thread that started it, or the component that contains it.

If you don't want to hang the JVM, you can declare it a daemon thread. Then it will shut down when everything else does. For more control, you need to make sure you terminate the thread in your own code at the appropriate time.

Answer 2

It will still be alive. A running thread constitutes a root for the GC. Averything reachable from a chain of references starting from a root is not eligible to GC. This means, BTW, that your panel won't be GCed either, since the thread holds an implicit reference to the panel ( EnclosingPanel.this ).

You need to make sure to stop the thread when you don't want it running anymore.

Answer 3

线程在完成其工作或您interrupt它之前不会死亡。

Answer 4

线程在退出 run() 方法时将终止，因此当组件通过 remove() 方法从其父组件中删除时，线程将永远不会终止。

Answer 5

Take a look at Component.removeNotify. In your component, keep a pointer to the thread:

public class MyPanel extends JPanel {
   private Thread thread = ...;

   public void removeNotify() {
      super.removeNotify();
      thread.interrupt();
   }
}

This method is called by awt itself when it decides to remove the native peer of the component (ie, the windows or linux component backing the awt component). As per the javadoc:

Makes this Component undisplayable by destroying it native screen resource. This method is called by the toolkit internally and should not be called directly by programs. Code overriding this method should call super.removeNotify as the first line of the overriding method.