exception handling for filter in spring

Question

I am handling exceptions in spring using @ExceptionHandler. Any exception thrown by controller is caught using method annotated with @ExceptionHandler and action is taken ac

Answer 1

If, like me, you're stuck with spring 3.1 (just 0.1 vesrsions behind @ControllerAdvice) you can try this solution I just came up with.

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So, you've heard of exception resolvers, right? If not, read here:

@Component
public class RestExceptionResolver extends ExceptionHandlerExceptionResolver {

    @Autowired
    //If you have multiple handlers make this a list of handlers
    private RestExceptionHandler restExceptionHandler;
    /**
     * This resolver needs to be injected because it is the easiest (maybe only) way of getting the configured MessageConverters
     */
    @Resource
    private ExceptionHandlerExceptionResolver defaultResolver;

    @PostConstruct
    public void afterPropertiesSet() {
        setMessageConverters(defaultResolver.getMessageConverters());
        setOrder(2); // The annotation @Order(2) does not work for this type of component
        super.afterPropertiesSet();
    }

    @Override
    protected ServletInvocableHandlerMethod getExceptionHandlerMethod(HandlerMethod handlerMethod, Exception exception) {
        ExceptionHandlerMethodResolver methodResolver = new ExceptionHandlerMethodResolver(restExceptionHandler.getClass());
        Method method = methodResolver.resolveMethod(exception);
        if (method != null) {
            return new ServletInvocableHandlerMethod(restExceptionHandler, method);
        }
        return null;
    }

    public void setRestExceptionHandler(RestExceptionHandler restExceptionHandler) {
        this.restExceptionHandler = restExceptionHandler;
    }

    public void setDefaultResolver(ExceptionHandlerExceptionResolver defaultResolver) {
        this.defaultResolver = defaultResolver;
    }
}

Then an example handler will look like this

@Component
public class RestExceptionHandler {

    @ExceptionHandler(ResourceNotFoundException.class)
    @ResponseStatus(HttpStatus.NOT_FOUND)
    @ResponseBody
    public Map handleException(ResourceNotFoundException e, HttpServletResponse response) {
        Map error = new HashMap<>();
        error.put("error", e.getMessage());
        error.put("resource", e.getResource());
        return error;
    }
 }

Of course you will not forget to register your beens

---

Then create a filter that is called before your desiered filter (optionally all of 'em)

Then in that filter

try{
   chain.doFilter(request, response);
catch(Exception e){
   exceptionResolver(request, response, exceptionHandler, e);
   //Make the processing stop here... 
   return; //just in case
}