Q) Explain about “throw”?

A)

->throw keyword is used to throw the exception explicitly(by the developer) after creating exception object.

Ex:

Throw new someException();

Or

someException e = new someException();

throw e;

->within the catch block, if we use throw keyword for throwing the exception programmatically. It is said that the Exception is “rethrown”. i.e. throw keyword is also used to “ rethrowing” of an exception.

voidsomepartofoneproject()

{

       somepartofoneproject();

}

voidsomepartofanotherproject()

{

       try

       {

              //some doubtful code

       }

       catch(ServletException e)

       {

              throw new seriousException();

       }

}

Explanation:

->in this second method contain doubtful code in try block.

->if exception raised by JVM, that is throws to catch block. But catch block is throwing. It is      called re throwing.

->but that re throwing object is not as it is original object of exception.

->catch throws converting new object to calling method.

->outside of the catch exception is throwing called throw.

->inside of the catch exception is again throwing. I.e. called re throwing.

->intimating the one part of application to another part of application is called re throwing.