Mega Code Archive
What happens if a method declares an unchecked exception
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/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
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* modification, are permitted provided that the following conditions
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*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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*
* Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
/** What happens if a method declares an unchecked exception?
* Some people seem to think that declaring a method in a throws
* clause is what makes it "checked". As we see here, this is not
* the case; checked-ness has only to do with an exception's place
* in Java's class inheritance hierarchy.
*/
public class ThrowsUnchecked {
public static void main(String[] argv) {
new ThrowsUnchecked().doTheWork();
}
/** This method demonstrates calling a method that might throw
* an exception, and catching the resulting exception.
*/
public void doTheWork() {
String s = " 42";
int i = testit(s); // Note: compiles with no try/catch.
System.out.println("parseit(" + s + ") returned " + i);
}
/** Model of a method that might throw an unchecked exception.
* @exception NumberFormatException if called with value 1.
*/
public int testit(String input) throws NumberFormatException {
return Integer.parseInt(input);
}
}
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