Throwable Hierarchy

Class Exception and class Error both descend from Throwable. A Java method can "throw" an object of class Throwable. (We will do this later on in this chapter.) For example, Scanner threw an exception when it tried to convert "rats" into an integer.

Exceptions are different from Errors because programs can be written to recover from Exceptions, but programs can't be written to recover from Errors. The rest of this chapter discusses Exceptions.