Spring rest controller exception handling

Question

How do I configure a single rest controller to handle exceptions for different API calls returning different object types?

@RequestMapping(method = RequestMethod.GET)
public ResponseEntity<Foo> method1() 

@RequestMapping(method = RequestMethod.GET)
public ResponseEntity<Bar> method2()

Let's say both method1() and method2() throws an instance of MyException, then I need to handle them differently the following way:

@ExceptionHandler(MyException.class)
@ResponseBody
public ResponseEntity<Foo> handleFoo(Exception ex) {
    //Return foo with error description
    Foo f = new Foo();
    f.setError(ex.getMessage());
    //Set f to response entity
    return new ResponseEntity<>(); 
}

@ExceptionHandler(MyException.class)
@ResponseBody
public ResponseEntity<Bar> handleBar(Exception ex) {
     //Return bar with error description
    Bar b = new Bar();
    b.setError(ex.getMessage());
    //Set b to response entity
    return new ResponseEntity<>(); 
}

When method1() throws an instance of MyException, then handleFoo() should be called. And for method2(), handleBar() should be called.

Is this possible in a single Rest controller or do I need 2 rest controllers for each method?

Answer 1

The advantage of @ExceptionHandler is that you can have the same exception from multiple places handled in a single place. You're looking for the opposite: handling an exception in multiple places/ways.

You can't achieve that within a single class and the annotation, but you can do it with a normal try/catch in method1() and method2().