EJ-57 Use Exceptions only for Exceptional Conditions

Ref: Effective Java by Joshua Bloch

When used to best advantage,exceptions can improve a program's readability, reliability, and maintainability. When used, inappropriately, they can have the opposite affect.

	// Horrible abuse of exceptions. Don't ever do this!
	try {
	int i = 0;
	while(true)
	range[i++].climb();
	} catch(ArrayIndexOutOfBoundsException e) {
	}

view raw AbuseOfExceptions.java hosted with ❤ by GitHub

Exceptions, as their name implies, to be used only for exceptional conditions; they should never be used for ordinary control flow.

This principle also has implications for API design. A well-designed API must not force its clients to use exceptions for ordinary control flow.

	for (Iterator i = collection.iterator(); i.hasNext(); ) {
	Foo foo = i.next();
	...
	}
	//If Iterator lacked the hasNext method, clients would be forced to do this instead:
	// Do not use this hideous code for iteration over a collection!
	try {
	Iterator i = collection.iterator();
	while(true) {
	Foo foo = i.next();
	...
	}
	} catch (NoSuchElementException e) {
	}

view raw IteratorAPI.java hosted with ❤ by GitHub