Page History

Never use return, break, continue, or throw statements within a finally block. When program execution enters a try block that has a finally block, the finally block always executes , regardless of whether the try block (or any associated catch blocks) executes to normal completion. Statements that cause the finally block to complete abruptly also cause the try block to complete abruptly and consequently suppress any exception thrown from the try or catch blocks. According to the Java Language Specification, §14.20.2, Execution of try-catch-finally [JLS 2005]:

...

In this noncompliant code example, the finally block completes abruptly because of a return statement in the block.:

class TryFinally {
  private static boolean doLogic() {
    try {
      throw new IllegalStateException();
    } finally {
      System.out.println("logic done");
      return true;
    }
  }
}

...

This compliant solution removes the return statement from the finally block.:

class TryFinally {
  private static boolean doLogic() {
    try {
      throw new IllegalStateException();
    } finally {
      System.out.println("logic done");
    }
    // Any return statements must go here; 
    // applicable only when exception is thrown conditionally
  }
}

...

For example, the following code does not violate this rule , because the break statement exits within the while loop , but not within the finally block.

class TryFinally {
  private static boolean doLogic() {
    try {
      throw new IllegalStateException();
    } finally {
      int c;
      try {
        while ((c = input.read()) != -1) {
          if (c > 128) {
            break;
          }
        }
      } catch (IOException x) {
        // forwardForward to handler
      }
      System.out.println("logic done");
    }
    // Any return statements must go here; applicable only when exception is thrown conditionally
  }
}

...

Automated Detection

Related Guidelines

...

...