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Saturday, February 25, 2012
Why it is mandatory to use "throws IOException”
Why it is mandatory to use "throws IOException" in main method while handling an external file operation, if the file is located within the local file system.
If you do handle the exception, then you need to put a try {...} catch(IOException e) {...}, but if you don't handle it, just declare the throws IOException in the current method.
It is not at all mandatory to use throws IOException. If you call a method that can throw an exception, though, you're required to either
ReplyDeleteCatch it, or
Declare that you're going to rethrow it.
The second one is what you're doing. The other one -- which is often the preferred technique -- is to catch and handle the exception yourself:
public static void main(String[] argv) {
try {
FileReader f = new FileReader("foo.txt");
// ... more
} catch (IOException ioe) {
System.out.println("Trouble reading from the file: " + ioe.getMessage());
}
}
AFAIK, it is not mandatory.
ReplyDeleteYou either handle the exception or you don't.
If you do handle the exception, then you need to put a try {...} catch(IOException e) {...}, but if you don't handle it, just declare the throws IOException in the current method.