JAVA Exception

abalfazl · Aug 30th, 2007, 03:36

What is difference between throw and throws?

May you give me an example about that?May you explain about override exception?

hschmitz · Aug 30th, 2007, 20:37

The throw keyword is used to actually throw an exception while the throws keyword just tells the compiler which exceptions may be thrown by a method.

Code: Select all

public Object pop() throws EmptyStackException
{
    Object obj;

    if (size == 0) {
        throw new EmptyStackException();
    }

    obj = objectAt(size - 1);
    setObjectAt(size - 1, null);
    size--;
    return obj;
}

See haw throws appears in the declaration of the method and throw appears in its body.

abalfazl · Aug 31st, 2007, 19:28

Hello!
Thanks!

But I mean an example for throw,and another for throws,Thanks in advance!

May someone give me a list of difference between checked and unchecked exceptions?why they called "checked" or "unchecked"

abalfazl · Sep 9th, 2007, 20:19

Hi!

http://java.ztor.com/fundamental/main/

Handling Exceptions
You can handle exception otherwise you must declare it. Also you can handle some exceptions and declare others.

Handle Exceptions

Code: Select all

public void myMethod() {
try {
  . . .
}
catch (ExceptionType1 e) {
  . . .
}
catch (ExceptionType2 e) {
  . . .
}
finally {
  . . .
}

Declare Exceptions

Code: Select all

public void myMethod() throws ExceptionType1,ExceptionType2 {
  . . .
}

May someone explain more about difference between these?When do we use declare exception?When to use handle exception?

Quote:

You declare that a method throws an exception if the problem can't be handled in the method. You handle the exception in the method if you can handle the error and continue with the method.

May show this by an example?

Thanks in advance