Item 62: Document all exceptions thrown by each method

A description of the exceptions thrown by a method is an important part of the documentation required to use the method properly. Therefore, it is critically important that you take the time to carefully document all of the exceptions thrown by each method.

Always declare checked exceptions individually, and document precisely the conditions under which each one is thrown using the Javadoc @throws tag. Don’t take the shortcut of declaring that a method throws some superclass of multiple exception classes that it can throw. As an extreme example, never declare that a method “throws Exception” or, worse yet, “throws Throwable.” In addition to denying any guidance to the method’s user concerning the exceptions that it is capable of throwing, such a declaration greatly hinders the use of the method, as it effectively obscures any other exception that may be thrown in the same context.