The Java Language Specification, Third Edition

BLOCKS AND STATEMENTS Execution of try–catch–finally 14.20.2
◆ If the finally block completes normally, then the try statement completes
abruptly for reason R.
◆ If the finally block completes abruptly for reason S, then the try statement
completes abruptly for reason S (and reason R is discarded).
The example:
class BlewIt extends Exception {
BlewIt() { }
BlewIt(String s) { super(s); }
}
class Test {
static void blowUp() throws BlewIt {
throw new NullPointerException();
}
public static void main(String[] args) {
try {
blowUp();
} catch (BlewIt b) {
System.out.println("BlewIt");
} finally {
System.out.println("Uncaught Exception");
}
}
}
produces the output:
Uncaught Exception
java.lang.NullPointerException
at Test.blowUp(Test.java:7)
at Test.main(Test.java:11)
The NullPointerException (which is a kind of RuntimeException) that is
thrown by method blowUp is not caught by the try statement in main, because a
NullPointerException is not assignable to a variable of type BlewIt. This
causes the finally clause to execute, after which the thread executing main,
which is the only thread of the test program, terminates because of an uncaught
exception, which typically results in printing the exception name and a simple
backtrace. However, a backtrace is not required by this specification.
DRAFT
401