Question

Why do I need to wrap my thrown custom exceptions with try/catch whilst trying to throw them, but I don’t have to do that for generic exceptions? Like in the example, my Exception subclass :

public class MyException extends Exception {
    public MyException(String msg) {
        super(msg);
    }
}

Throwing exceptions :

public class Exe {

    private static void testex(String test) {
        if (null!=test) {
            throw new UnsupportedAddressTypeException();
        } else {//Removing try/catch block results in compile failure
          try {
            throw new MyException("message");
          } catch (MyException e) {
            e.printStackTrace();
          }
        }
    }
}

Answer 1

UnsupportedAddressTypeException is a subclass of RuntimeException, and from the JavaDoc:

RuntimeException is the superclass of those exceptions that can be thrown during the normal operation of the Java Virtual Machine.

A method is not required to declare in its throws clause any subclasses of RuntimeException that might be thrown during the execution of the method but not caught.