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Does JVM throw exception from OS

I was asked this question which JVM throws Exception for OS if main throws? The JVM stops the application execution, but where will this exception be handled?

public static void main(String[] args) throws Exception {
    display();
}

public static void display() throws Exception {
    throw new RuntimeException();
}

If it can happen with any exception, please specify.

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2 answers


It is not handled by the OS, but by the JVM itself. From the Java Language Specification §11.3 :

If the catch clause cannot handle the exception, then the current thread (the thread that encountered the exception) exits

Your JVM will run with a single thread that will terminate. Then the JVM will close, according to JLS §12.8 (emphasis mine):



The program ends all of its activity and exits when one of two things happens:

  • All threads that are not daemon threads terminate.
  • Some threads call the exit method of the Runtime class or the System class, and the exit operation is not prohibited by the security manager.

This can happen with any type of exception at all. Note that in terms of the language specification, "exception" is actually java.lang.Throwable

any of its subclasses . This means it Error

also terminates threads / JVMs and everything that inherits from Throwable

, not just objects extending Exception

.

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Java runs in the JVM, so all exceptions will be handled in the JVM. Just for your answer, Java exceptions will not go to the OS level. In other words, you cannot catch JAVA exceptions at the OS level.



Hope this answers your question.

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