I have a controller to receive POST requests and return a JSON output. An exception handler which was implemented inside the controller class worked fine.

I have tried to add Global exception handling with `@ControllerAdvice` annotation, but this doesn't work in my solution. I don't think the global exception handler class is being loaded.

Below is my controller class:

```
package hello;

@Controller
@RequestMapping("/v1")
public class MyController {

  @RequestMapping(value = "/saveEmployee", method = RequestMethod.POST, produces = "application/json")
  @ResponseBody
  public String saveEmployee(@Valid @RequestBody Employee employee) {
    return "{ \"name\":\"" + employee.getEmail() + "\"}";
  }
}

```

Below is Global exception handler class:

```
package util;

@ControllerAdvice
public class MyControllerAdvice {

  @ExceptionHandler(MethodArgumentNotValidException.class)
  // @ResponseStatus(HttpStatus.BAD_REQUEST)
  @ResponseBody
  public String processValidationError(MethodArgumentNotValidException ex) {
    BindingResult result = ex.getBindingResult();
    FieldError fieldError = result.getFieldError();
    String code = fieldError.getCode();
    String field = fieldError.getField();
    String message = fieldError.getDefaultMessage();
    message = "{ \"Code\":\"" + code + "\",\"field\":\"" + field + "\",\"Message\":\"" + message + "\"}";
    return message;
  }
}

```

Below are my configurations:

```
package hello;

@SpringBootApplication
public class Application {

    @Bean
    public MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        messageSource.setBasename("classpath:messages");
        messageSource.setDefaultEncoding("UTF-8");
        return messageSource;
    }

    @Bean
    public LocalValidatorFactoryBean validator() {
        LocalValidatorFactoryBean bean = new LocalValidatorFactoryBean();
        bean.setValidationMessageSource(messageSource());
        return bean;
    }

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

```

Spring boot version : 2.0.3.RELEASE