在 Java 中，我们抛出的异常没有被默认处理程序捕获？ 正确的

Question

But then in the following program, when the exception is re-thrown in the catch statement, without the throws clause, no error is there?? How?

Class Throwdemo {
  static void demoproc(){
    try{
        throw new NullPoinerException ("demo");
    }catch(NullPointerException e) {
        System.out.println("Caught inside demoproc."); 
        throw e;
    }
  }
  public static void main(String Args[]){
    try[
        demoproc();
    }catch(NullPointerException e) {
            System.out.println("Recaught : " + e);
    }
}
}

THe output is

Caught inside demoproc.
Recaught : java.lang.NullPointerException: demo

Answer 1

You only need throws clause for checked Exceptions .

Answer 2

Observe these lines:

public static void main(String Args[]){
    try[

The try has a bracket, not a brace. Probably, you've been unsuccessfully compiling the program, and then re-running the old class file.

Answer 3

Because NullPoinerException is a RuntimeException . It doesn't need a throws clause.

Answer 4

Unable to get what you meant be default handler. When the execption is thrown by

throw new NullPoinerException ("demo");

This is caught by the try catch block surrounding it.

Catch block in turn throws exception, which is caught by try catch block in main.

Hope this helps.

Edit after your comment: Also NullPoinerException exception is unchecked exception thus need not be mentioned as throws.