Java Language -- Handling Runtime Errors Using Exceptions
The language itself supports concept of an exception
Java supports a hierarchical model of exceptions which allow and indeed require user to supply suitable handlers for any exception that can occur in a Java program
Note exceptions that can occur in a method must either be caught (i.e. handled inside method) or thrown (i.e. returned to callee)
Thrown exceptions are like returned arguments and are for instance part of interface to a method
Exceptions are all (at some level in hierarchy) subclasses of Throwable class