exception.getMessage() output with class name

Question

I'm trying to fix an issue, in my application I have this code

try {   object1.method1(); } catch(Exception ex) {    JOptionPane.showMessageDialog(nulll, "Error: "+ex.getMessage()); } 

and the object1 would do something like that:

public void method1() {    //some code...    throw new RuntimeException("Cannot move file"); } 

I get a messsage in my option pane like this: Error: java.lang.RuntimeException: Cannot move file

but I used getMessage and not toString method, so the name of the class shouldn´t appear, right?

What I am doing wrong? I already tryied with a lot of exceptions, even Exception itself. I'm looking to solve this no without the need to implement my own Exception subclass

PROBLEM SOLVED - thank you all!

The try and catch were actually being called in get() method from SwingWorker which constructs an ExecutionException with my exception thrown from doInBackground() I fixed doing this:

@Override protected void done() {     try {         Object u = (Object) get();         //do whatever u want     } catch(ExecutionException ex) {         JOptionPane.showMessageDialog(null, "Error: "+ex.getCause().getMessage());     } catch(Exception ex) {         JOptionPane.showMessageDialog(null, "Error: "+ex.getMessage());     } } 

Answer 1

I think you are wrapping your exception in another exception (which isn't in your code above). If you try out this code:

public static void main(String[] args) {     try {         throw new RuntimeException("Cannot move file");     } catch (Exception ex) {         JOptionPane.showMessageDialog(null, "Error: " + ex.getMessage());     } } 

...you will see a popup that says exactly what you want.

---

However, to solve your problem (the wrapped exception) you need get to the "root" exception with the "correct" message. To do this you need to create a own recursive method getRootCause:

public static void main(String[] args) {     try {         throw new Exception(new RuntimeException("Cannot move file"));     } catch (Exception ex) {         JOptionPane.showMessageDialog(null,                                       "Error: " + getRootCause(ex).getMessage());     } }  public static Throwable getRootCause(Throwable throwable) {     if (throwable.getCause() != null)         return getRootCause(throwable.getCause());      return throwable; } 

Note: Unwrapping exceptions like this however, sort of breaks the abstractions. I encourage you to find out why the exception is wrapped and ask yourself if it makes sense.

Answer 2

My guess is that you've got something in method1 which wraps one exception in another, and uses the toString() of the nested exception as the message of the wrapper. I suggest you take a copy of your project, and remove as much as you can while keeping the problem, until you've got a short but complete program which demonstrates it - at which point either it'll be clear what's going on, or we'll be in a better position to help fix it.

Here's a short but complete program which demonstrates RuntimeException.getMessage() behaving correctly:

public class Test {     public static void main(String[] args) {         try {             failingMethod();         } catch (Exception e) {             System.out.println("Error: " + e.getMessage());         }     }             private static void failingMethod() {         throw new RuntimeException("Just the message");     } } 

Output:

Error: Just the message