14.18.2

Execution of

try catch finally

BLOCKS AND STATEMENTS

If execution of the

try

 block completes abruptly for any other reason

R

, then

the

finally

 block is executed. Then there is a choice:

N

If the

finally

 block completes normally, then the

try

 statement completes

abruptly for reason

R

.

N

If the

finally

 block completes abruptly for reason

S

, then the

try

 state 

ment 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 ( 20.21.31), which results in printing the exception name and a simple

backtrace.

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