Spring MVC controller advice for handling custom exceptions

RestExceptionHandler.java

import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.servlet.error.ErrorAttributes;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.context.request.ServletWebRequest;

@ControllerAdvice
@ResponseBody
public class RestExceptionHandler {

  private final ErrorAttributes errorAttributes;

  @Autowired
  public RestExceptionHandler(ErrorAttributes errorAttributes) {
    this.errorAttributes = errorAttributes;
  }

  @ExceptionHandler({NotFoundException.class})
  public ResponseEntity<?> handleCustomExceptions(
      HttpServletRequest request) {
    return respondWith(request, HttpStatus.NOT_FOUND);
  }

  private ResponseEntity<?> respondWith(HttpServletRequest request,
                                        HttpStatus status) {
    Map<String, Object> body = getErrorAttributes(request);
    body.put("status", status.value());
    return new ResponseEntity<>(body, status);
  }

  private Map<String, Object> getErrorAttributes(HttpServletRequest request) {
    final ServletWebRequest webRequest = new ServletWebRequest(request);
    return errorAttributes.getErrorAttributes(webRequest, false);
  }
}

For a validation error response is

{
  "timestamp": "2019-06-05T15:46:57.502+0000",
  "status": 400,
  "error": "Bad Request",
  "errors": [
    {
      "codes": [
        "PrivateZoneName.zoneCreatePrivate.name",
        "PrivateZoneName.name",
        "PrivateZoneName.java.lang.String",
        "PrivateZoneName"
      ],
      "arguments": [
        {
          "codes": [
            "zoneCreatePrivate.name",
            "name"
          ],
          "arguments": null,
          "defaultMessage": "name",
          "code": "name"
        }
      ],
      "defaultMessage": "zone name must be private",
      "objectName": "zoneCreatePrivate",
      "field": "name",
      "rejectedValue": null,
      "bindingFailure": false,
      "code": "PrivateZoneName"
    },
    {
      "codes": [
        "NotBlank.zoneCreatePrivate.name",
        "NotBlank.name",
        "NotBlank.java.lang.String",
        "NotBlank"
      ],
      "arguments": [
        {
          "codes": [
            "zoneCreatePrivate.name",
            "name"
          ],
          "arguments": null,
          "defaultMessage": "name",
          "code": "name"
        }
      ],
      "defaultMessage": "may not be empty",
      "objectName": "zoneCreatePrivate",
      "field": "name",
      "rejectedValue": null,
      "bindingFailure": false,
      "code": "NotBlank"
    }
  ],
  "message": "Validation failed for object='zoneCreatePrivate'. Error count: 2",
  "path": "/api/tenant/aaaaaa/zones"
}

When the custom exception is handled, example response is

{
  "timestamp": "2019-06-05T15:54:26.292+0000",
  "status": 404,
  "error": "None",
  "message": "No zone found named asdfasdf"
}

Uses the same strategy as BasicErrorController's error method:

https://github.com/spring-projects/spring-boot/blob/master/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/error/BasicErrorController.java#L97-L102

Generalized here https://github.com/racker/salus-common/blob/7b9a9d099e224535bd4d8f33070cb373952c9ed7/src/main/java/com/rackspace/salus/common/web/AbstractRestExceptionHandler.java