Spring - Manage custom Exception page - spring

Question

I'm trying to manage a custom error page with my custom exception.
I have this exception
#ResponseStatus(value=HttpStatus.NOT_FOUND, reason="Inesistente")
public class ResourceNotAccessibleException extends Throwable{
public ResourceNotAccessibleException(String message){
super(message);
}
}
which i want to respond with a 404 error.
Than i'm managing an error controller
#ControllerAdvice
public class ErrorController {
#ExceptionHandler({ResourceNotAccessibleException.class})
public ModelAndView getErrorPage(HttpServletRequest request, Throwable ex) {
String errorMsg = "";
int httpErrorCode = getErrorCode(request);
switch (httpErrorCode) {
case 404: {
logger.error("Status Error " + httpErrorCode , ex.getMessage());
errorMsg = messageSource.getMessage("errorMessage", new Object[] { uuid, +httpErrorCode }, locale);
break;
}
case 400: {
errorMsg = "BAD REQUEST";
break;
}
case 500: {
errorMsg = messageSource.getMessage("errorMessage", new Object[] { uuid, +httpErrorCode }, locale);
logger.error("Status Error " + httpErrorCode , ex.getMessage());
break;
}
}
ModelAndView mav = new ModelAndView();
mav.addObject("errorMsg", errorMsg);
mav.setViewName("error");
return mav;
}
Now, in my controller if i have something like
if(object==null) {
throw new ResourceNotAccessibleException("Resource does not exist");
}
I should see my error view, but i'm getting the classic white error page, in my log i see the exception being hit..

Answer 1

The ResourceNotAccessibleException should extend Exception or RuntimeException and not Throwable. More info
If you can't change exception type, probably you could try ExceptionHandlerExceptionResolver or this awesome post about Spring exception handling
One more thing, you probably want to add some #ResponseStatus info above getErrorPage, because you are handling this exeption and #ResponseStatus annotation above the ResourceNotAccessibleException will never trigger.
So i think something like this should work:
#ControllerAdvice
public class ErrorController {
#ResponseStatus(value= HttpStatus.NOT_FOUND) // <= important
#ExceptionHandler({ResourceNotAccessibleException.class})
public ModelAndView getErrorPage(HttpServletRequest request, Throwable ex) {
String errorMsg = "";
// ... some code here
ModelAndView mav = new ModelAndView();
mav.addObject("errorMsg", errorMsg);
mav.setViewName("error");
return mav;
}
}
public class ResourceNotAccessibleException extends Exception{ // <= important
public ResourceNotAccessibleException(String message){
super(message);
}
}
If this doesn't work, you can also try to change resource view file name to something like errorPage.jsp or errorPage.html and set it like mav.setViewName("errorPage");

Answer 2

You need to replace the default error pages in your web container and map a status code to a particular error page.
Here are the changes you need to make:
If it's a Jetty container, here are the changes:
#Bean
public JettyEmbeddedServletContainerFactory
containerFactory(
#Value("${server.port:8080}") final String port,
#Value("${jetty.threadPool.maxThreads:600}") final String maxThreads,
#Value("${jetty.threadPool.minThreads:10}") final String minThreads,
#Value("${jetty.threadPool.idleTimeout:5000}") final String idleTimeout) {
final JettyEmbeddedServletContainerFactory factory =
new JettyEmbeddedServletContainerFactory(Integer.valueOf(port));
...
factory.addErrorPages(new ErrorPage(HttpStatus.NOT_FOUND,
"/error-info.html"));
...
return factory;
}
If it's a Tomcat container, here are the changes:
#Bean
public EmbeddedServletContainerCustomizer container() {
return new EmbeddedServletContainerCustomizer() {
#Override
public void customize(
ConfigurableEmbeddedServletContainer container) {
container.addErrorPages(new
ErrorPage(HttpStatus.NOT_FOUND, "/error-info.html"));
}
};
}
For your ErrorController, don't set view name. It will pick the view from the error page mapping which was set earlier.
#ControllerAdvice
public class ErrorController {
#ExceptionHandler(ResourceNotAccessibleException.class)
#ResponseStatus(value = HttpStatus.NOT_FOUND)
public ModelAndView handleResourceNotAccessibleException(
HttpServletRequest req, ResourceNotAccessibleException ex) {
...
ModelAndView mav = new ModelAndView();
mav.addObject("errorMsg", errorMsg);
retrun mav;
}
}
Location of error-info.html or jsp under resources/static