Java – Does a finally block always get executed in Java


Considering this code, can I be absolutely sure that the finally block always executes, no matter what something() is?

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

Best Solution

Yes, finally will be called after the execution of the try or catch code blocks.

The only times finally won't be called are:

  1. If you invoke System.exit()
  2. If you invoke Runtime.getRuntime().halt(exitStatus)
  3. If the JVM crashes first
  4. If the JVM reaches an infinite loop (or some other non-interruptable, non-terminating statement) in the try or catch block
  5. If the OS forcibly terminates the JVM process; e.g., kill -9 <pid> on UNIX
  6. If the host system dies; e.g., power failure, hardware error, OS panic, et cetera
  7. If the finally block is going to be executed by a daemon thread and all other non-daemon threads exit before finally is called