Exceptions and Assertions - The Java Programming Language - page 424

You cannot put a superclass catch clause before a catch of one of its sub-
classes. The catch clauses are examined in order, so a catch that picked
up one exception type before a catch for an extended type of exception
would be a mistake. The first clause would always catch the exception,
and the second clause would never be reached. The compiler will not
accept the following code:
class SuperException extends Exception { }
class SubException extends SuperException { }
class BadCatch {
public void goodTry() {
/* This is an INVALID catch ordering */
try {
throw new SubException();
} catch (SuperException superRef) {
// Catches both SuperException and SubException
} catch (SubException subRef) {
// This would never be reached
}
}
}
Only one exception is handled by any single encounter with a TRy clause.
If a catch or finally clause throws another exception, the catch clauses
of the try are not reexamined. The catch and finally clauses are outside
the protection of the try clause itself. Such exceptions can, of course,
be handled by any encompassing try block in which the inner catch or
finally clauses were nested.
12.4.1. finally
The finally clause of a try statement provides a mechanism for execut-
ing a section of code whether or not an exception is thrown. Usually, the
finally clause is used to clean up internal state or to release non-object