Exceptions

[Vineela Devi]

Hi,
Is the hierachy significant in throws statement.i.e.is it illeagl to declare a method as

void method() throws Exception, IOException{
throw new IOException();
}
ofcourse i know tht there is no need to throw IOException in the above method . but i just want to know whether hierachy is significant in throws statement.

Thanks in advance.
vineela

[Vicken Karaoghlanian]

If there is a throws clause in the signature of a method, then that method can actually throw one of those:

No exceptions at all.

The same exception that is declared in the method signature.

Any exception that is a subset of the exception declared in the method's signature.

[Vineela Devi]

hi Vicken,
Thanks for the reply.I know the points u have specified.
i wanted to know whether the code posted by me is illegal coz in some Certification book, it is mentioned tht the hierachy is significant in throws clause.
vineela

[Sudhakar Krishnamurthy]

Nope, their is no hierarchy that you need to follow, your code should compile fine. But i hope you understand you would never have to do that since the base class exception is going to take precedence over the subclass exceptions when it is caught.

[Thomas De Vos]

Additionally on the three bullet points mentioned in the posting from Vicken. The method can throw also unchecked exceptions like: NullPointerException, RuntimeException, etc.