How do I avoid the "local variable may not have been initialized" Java compilation error? (yes, seriously!)

Question

Before you say that this question has already been answered tons of times, here is my code snippet:

final int x;
try {
    x = blah(); 
} catch (MyPanicException e) {
    abandonEverythingAndDie();
}
System.out.println("x is " + x);

If invoking abandonEverythingAndDie() has the effect of ending the execution of the whole program (say because it invokes System.exit(int) ), then x is always initialized whenever it is used.

Is there a way in the current Java language to make the compiler happy about variable initialization, by informing it that abandonEverythingAndDie() is a method which never returns control to the caller?

I do not want to

• remove the final keyword
• initialize x while declaration,
• nor to put the println in the scope of the try...catch block.

Answer 1

Not without cheating a little by providing a little bit of extra information to the compiler:

final int x;
try {
    x = blah();
} catch (MyPanicException e) {
    abandonEverythingAndDie();
    throw new AssertionError("impossible to reach this place"); // or return;
}
System.out.println("x is " + x);

You can also make abandonEverythingAndDie() return something (only syntactically, it will of course never return), and call return abandonEverythingAndDie():

final int x;
try {
    x = blah();
} catch (MyPanicException e) {
    return abandonEverythingAndDie();
}
System.out.println("x is " + x);

and the method:

private static <T> T abandonEverythingAndDie() {
    System.exit(1);
    throw new AssertionError("impossible to reach this place");
}

or even

throw abandonEverythingAndDie();

with

private static AssertionError abandonEverythingAndDie() {
    System.exit(1);
    throw new AssertionError("impossible to reach this place");
}