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throw new Exception() confusion

Sekhar Kadiyala
Ranch Hand

Joined: Feb 17, 2004
Posts: 170
From the below example, i thought when we encounter the line 'throw new Exception();', it would actually go back to the calling method (main in this case). But why it is getting into catch block?
Then under what circutances would this throw new Exception() will goto the calling method?
Please help. Thanks in advance


PMP CSQA SCJP SCWCD SCBCD INS 21 INS 23
Sekhar Kadiyala
Ranch Hand

Joined: Feb 17, 2004
Posts: 170
Sorry i missed telling you the output. It would be 13423
Sindhur Sat
Greenhorn

Joined: Feb 23, 2004
Posts: 23
Hi Sekhar,

what circutances would this throw new Exception() will goto the calling method?

If you remove the try,catch and finally blocks and declare the exception(throws Exception)in your method declaration:

it will be propogated to the calling method.
Since you are handling it it will not be propagated.
Sindhur.
Corey McGlone
Ranch Hand

Joined: Dec 20, 2001
Posts: 3271
Right - when an exception is thrown, it will be caught by the nearest matching catch block. If the exception is thrown within a try block that has a matching catch block and/or finally block, the exception is handled there.
If the exception is thrown within a try block without a matching catch or finally block (or it's a RuntimeException), the exception will be propogated to the method that invoked this one. It will then be handled there or, if that method doesn't handle the exception, it will propogate to the method that invoked that one, and so on.
Of course, if you're not going to handle a given exception within a method that might throw one, you must declare that the method in question is capable of throwing such an exception (by adding "throws Exception" to the end of the method signature). Once you've done that, any methods that invoke this one will be required to handle that exception (or throw it).


SCJP Tipline, etc.
Sekhar Kadiyala
Ranch Hand

Joined: Feb 17, 2004
Posts: 170
Thanks guys! I learned one more thing!! Just 5 more days!!! i can't wait to complete the exam!!!
 
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