The Java® Language Specification, Java SE 7 Edition, Fourth Edition

11.2. Compile-Time Checking of Exceptions

The Java programming language requires that a program contains handlers for checked exceptions which can result from execution of a method or constructor. For each checked exception which is a possible result, the throws clause for the method (§8.4.6) or constructor (§8.8.5) must mention the class of that exception or one of the superclasses of the class of that exception (§11.2.3).

This compile-time checking for the presence of exception handlers is designed to reduce the number of exceptions which are not properly handled. The checked exception classes (§11.1.1) named in the throws clause are part of the contract between the implementor and user of the method or constructor. The throws clause of an ...