Spring MVC @ControllerAdvice Annotation Example
June 28, 2019
@ControllerAdvice annotation is a specialization of @Component. The classes annotated with @ControllerAdvice are auto detected by classpath scanning. The use of @ControllerAdvice is advising all or selected controllers for @ExceptionHandler, @InitBinder and @ModelAttribute. What we have to do is create a class annotated with @ControllerAdvice and create required method which will be annotated with @ExceptionHandler for global exception handling, @InitBinder for global init binding and @ModelAttribute for global model attributes addition. Whenever a request comes to controller and its method with @RequestMapping and if there is no locally defined @ExceptionHandler, @InitBinder and @ModelAttribute, the globally defined class annotated with @ControllerAdvice is served.
@ControllerAdvice has attributes annotations, assignableTypes and basePackages . To use @ControllerAdvice, we should use @EnableWebMvc annotation in our java config.
Create a class Annotated with @ControllerAdvice
Find the sample class annotated with @ControllerAdvice. Here we are declaring methods for @ExceptionHandler, @InitBinder and @ModelAttribute to understand how to use it. We are using basePackages attribute of @ControllerAdvice to limit the controller classes. In this attribute we can define the array of base packages of controllers which can be used by @ControllerAdvice class, if not used basePackages attribute, then all controllers in classpath annotated with @Controller will be served by our @ControllerAdvice class.GlobalControllerAdvice.java
@ControllerAdvice(basePackages = {"com.concretepage.controller"} )
public class GlobalControllerAdvice {
@InitBinder
public void dataBinding(WebDataBinder binder) {
SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
dateFormat.setLenient(false);
binder.registerCustomEditor(Date.class, "dob", new CustomDateEditor(dateFormat, true));
}
@ModelAttribute
public void globalAttributes(Model model) {
model.addAttribute("msg", "Welcome to My World!");
}
@ExceptionHandler(FileNotFoundException.class)
public ModelAndView myError(Exception exception) {
ModelAndView mav = new ModelAndView();
mav.addObject("exception", exception);
mav.setViewName("error");
return mav;
}
}
Create Controller
Find the controller with a @RequestMapping method for the demo. Here we have also defined a controller specific @InitBinder method.MyWorldController.java
@Controller
@RequestMapping("/myworld")
public class MyWorldController {
@Autowired
private UserValidator userValidator;
@RequestMapping(value="signup", method = RequestMethod.GET)
public ModelAndView user(){
return new ModelAndView("user","user",new User());
}
@InitBinder
public void dataBinding(WebDataBinder binder) {
binder.addValidators(userValidator);
}
@RequestMapping(value="save", method = RequestMethod.POST)
public String createUser(@ModelAttribute("user") @Valid User user,BindingResult result, ModelMap model)
throws FileNotFoundException {
if(result.hasErrors()) {
return "user";
}
if(user.getName().equals("exception")) {
throw new FileNotFoundException("Error found.");
}
System.out.println("Name:"+ user.getName());
System.out.println("Date of Birth:"+ user.getDob());
return "success";
}
}
