multithreading - Java Thread: Run method cannot throw checked exception

Question

In Java thread, the 'run' method cannot throw a 'checked exception'. I came across this in the Core Java (vol 1) book. Can someone please explain the reasoning behind it?

Answer 1

Can someone please explain the reasoning behind it?

Yes, because any exception you throw in run method will be carefully ignored by JVM. Thus, throwing it there is probably a mistake (unless you have specific exception handler for the thread, see the docs about that). No reason to incite potentially erroneous behaviour.

Or, with an example.

 class MyThread extends Thread {
     public void run() {
         throw new RuntimeException();
     }
 }

...

new MyThread().start();
// here thread dies silently with no visible effects at all

edit

Why can't the parent thread 'catch' the exception from the spawned 'child' thread?

@chaotic3quilibrium has already noted in his comment why not: because parent thread has likely moved on already.

new MyThread().start(); // launch thread and forget

// 1000 lines of code further...
i = i + 1; // would you like exception from child thread to be propagated here?