Does finally always execute in Java?

考虑到这个代码，我可以绝对确定finally块总是执行，不管什么something()是什么？

try {  
    something();  
    return success;  
}  
catch (Exception e) {   
    return failure;  
}  
finally {  
    System.out.println("i don't know if this will get printed out.");
}

---

Yes, finally will be called.

The only times finally won't be called are:

If you invoke System.exit() ;

If the JVM crashes first;

If the JVM reaches an infinite loop (or some other non-interruptable, non-terminating statement) in the try or catch block;

If the OS forcibly terminates the JVM process; eg "kill -9 " on UNIX.

If the host system dies; eg power failure, hardware error, OS panic, etcetera.

---

Example code:

public static void main(String[] args) {
    System.out.println(Test.test());
}

public static int test() {
    try {
        return 0;
    }
    finally {
        System.out.println("finally trumps return.");
    }
}

Output:

finally trumps return. 
0

---

Also, although it's bad practice, if there is a return statement within the finally block, it will trump any other return from the regular block. That is, the following block would return false:

try { return true; } finally { return false; }

Same thing with throwing exceptions from the finally block.

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