In Chapter 27, you learned that Java expects you to acknowledge that a method may lead to an error, such as an attempt to open a nonexistent file. Your acknowledgment may appear in the method in the form of the keyword throws and the name of the exception class associated with the error. Such an acknowledgment merely passes the problem up to the calling method, which must itself acknowledge the possibility of an error.

In this unit, you learn about a way not only to acknowledge that a method may lead to exceptional behavior, but also to specify the appropriate response to that behavior.