Customize Spring Boot error response code without changing the default body - java

Spring Boot by default returns a response body for exceptions that meets my needs out of the box:
{
"timestamp": 1587794161453,
"status": 500,
"error": "Internal Server Error",
"exception": "javax.persistence.EntityNotFoundException",
"message": "No resource exists for the given ID",
"path": "/my-resource/1"
}
However, I would like to customize the response code for different types of exceptions thrown by my application. Some of the exceptions are not ones I own, so I can't just stick a #ResponseStatus annotation on the exception class. I've tries using an #ExceptionHandler method with #ResponseStatus, but that is overwriting the response body, which I don't wish to happen. For instance, I would like to map javax.persistence.EntityNotFoundException to return status code 404.
#ExceptionHandler
#ResponseStatus(HttpStatus.NOT_FOUND)
public void handleEntityNotFoundException(EntityNotFoundException e) {
// This method returns an empty response body
}
This question is similar to mine, but it is also attempting to adjust the response body. I am hoping that there is a shorter, more idiomatic way of adjusting just the status code and not the body.

It turns out that this answer to the question I mentioned had the exact solution needed to solve this problem, even though it didn't quite fully the question asked. The trick was dropping the use of #ResponseStatus from the method, and manually setting the status on the HttpServletResponse using HttpServletResponse.sendError(). This serves the standard Spring Boot exception response, but with the updated status code.
#ExceptionHandler
public void handleEntityNotFoundException(EntityNotFoundException e, HttpServletResponse response) throws IOException {
response.sendError(HttpServletResponse.SC_NOT_FOUND);
}
{
"timestamp": 1587794161453,
"status": 404,
"error": "Not Found",
"exception": "javax.persistence.EntityNotFoundException",
"message": "No resource exists for the given ID",
"path": "/my-resource/1"
}

Related

How to handle 404 exceptions using #ControllerAdvice and #ExceptionHandler?

I have a problem with Spring's exception handling for controllers. I have a class annotated with #RestControllerAdvice with a couple of #ExceptionHandler's, like this:
#ExceptionHandler(HttpRequestMethodNotSupportedException::class)
fun methodNotSupportedException(
exception: HttpRequestMethodNotSupportedException,
request: HttpServletRequest
): ResponseEntity<ApiError> {
logger().error("Method not supported: {}", exception.message)
val methodNotAllowed = HttpStatus.METHOD_NOT_ALLOWED
val apiError = logAndBuildApiError(request, methodNotAllowed, exception)
return ResponseEntity(apiError, methodNotAllowed)
}
and they work perfectly fine. In this case, when I'm trying to use an non-implemented HTTP method like POST:
{
"requestUri": "/api/v1/items",
"status": 405,
"statusText": "Method Not Allowed",
"createdAt": "2023-01-12T16:50:36.55422+02:00",
"errorMessage": "Request method 'POST' not supported"
}
What I would like to achieve is to handle situations when someone is trying to reach an non-existing endpoint, i.e. the correct one is GET http://localhost:8080/api/v1/items.
But when I'm trying to reach http://localhost:8080/api/v1/itemss, which is of course nonexistent, I recieve a regular Spring whitelabel error page, but I would like to receive a JSON like in the former example:
{
"requestUri": "/api/v1/itemss",
"status": 404,
"statusText": "Not Found",
"createdAt": "2023-01-12T16:52:06.932108+02:00",
"errorMessage": "Some error message"
}
How do I implement a #ExceptionHandler so it could handle exceptions related to non-existing resources?
spring.mvc.throw-exception-if-no-handler-found works in conjunction with
spring.mvc.static-path-pattern. By default, the static path pattern is /**, which includes the whitelabel error pages that you're seeing.
See https://github.com/spring-projects/spring-boot/pull/31660
and https://gitter.im/spring-projects/spring-boot?at=62ba1378568c2c30d30790af
and https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#web.servlet.spring-mvc.static-content
Option one is to set these two properties in your configuration.
spring:
mvc:
throw-exception-if-no-handler-found: true
static-path-pattern: /static
Option 2 is to add #EnableWebMvc to your spring boot application, and set the spring.mvc.throw-exception-if-no-handler-found property to true. By adding EnableWebMvc you'll be getting the WebMvcConfigurationSupport bean, which will cause Spring not to initialize the WebMvcAutoConfiguration and thereby not set the static-path-pattern.

Handle Custom Validations and Exceptions in REST with SpringBoot

Sample Project Attached Here
I am following this article API Error Handling (also please suggest if there is a better way to do this) to handle exceptions and validations in a generic way in my spring boot rest service. (i am new to spring and rest, so i am going through different articles for my requirement)
Basic idea about the requirement:
(Need to validate the POST request and send the validation errors to the client in a structure way. There could be multiple validation errors)
Whenever i get a POST request from my client, i need to validate the RequestBody. So I added #Valid on the parameter and #NotNull on the properties which i want to validate. Upon receiving the POST request spring is validating the request and throwing MethodArgumentNotValidException which is fine since i have some mandatory field missing.
I am handling it in a common place with #ControllerAdvice. After hitting the appropriate method handleMethodArgumentNotValid(...), i am constructing my custom error response APICustomError which i following from the above mentioned article.
When i have multiple validation errors, i am able to loop all the errors and adding it to a list and constructing the ResponseEntity with my custom error.
But the returned ResponseEntity does not have my added validation errors.
i understood the article and implemented the same in my project but really didn't get what i am missing.
The below is the output said in the article and what i am expecting is:
{
"apierror":{
"status":"BAD_REQUEST",
"timestamp":"10-07-2019 12:53:24",
"message":"Validation error",
"subErrors":[
{
"object":"person",
"field":"id",
"rejectedValue":null,
"message":"ID cannot be null"
},
{
"object":"person",
"field":"name",
"rejectedValue":null,
"message":"name cannot be null"
}
]
}
}
but below is what i am getting. i don't see the subErrors part at all.
{"message":"Validation Error","debugMessage":null,"detail":null,"httpStatus":"BAD_REQUEST","timestamp":"2019-07-10T17:08:00.52"}
Any help is appreciated.
You need to add getter and setters in APICustomError for properly serialize your object. Also you need public constructor and getter/setters for inner class APIValidationError. I suggest you use Lombok.
After that you will see the errors, something like this...
{
"message": "Validation Error",
"debugMessage": null,
"subErrors": [
{
"object": "personDTO",
"field": "id",
"rejectedValue": null,
"validationErrorMessage": "ID cannot be null."
}
],
"detail": null,
"httpStatus": "BAD_REQUEST",
"timestamp": "2019-07-10T10:25:44.1705441"
}
Try this one
In your controller advice
protected ResponseEntity<Object> handleMethodArgumentNotValid(
MethodArgumentNotValidException ex,
HttpHeaders headers,
HttpStatus status, WebRequest request) {
Response response = new Response();
List<FieldError> errors = ex.getBindingResult().getFieldErrors();
List<SubError> errors = new ArrayList<>();
for (FieldError e : errors) {
SubError error = new SubError():
error.setMessage(String.format(MESSAGE_FORMAT, egetCOde));
errors.add(error);
}
response.setSubError(errors);
return new ResponseEntity(response, HttpStatus.BAD_REQUEST);
}

Where does Spring Data REST build Exception JSON reply?

I'm using Spring Boot 1.5.3, Spring Data REST, Spring HATEOAS, Hibernate.
Spring Data REST manage in a pretty way exceptions, returning a well formatted JSON object like this:
{
"timestamp": "2017-06-24T16:08:54.107+0000",
"status": 500,
"error": "Internal Server Error",
"exception": "org.springframework.dao.InvalidDataAccessApiUsageException",
"message": "org.hibernate.TransientPropertyValueException: Not-null property references a transient value - transient instance must be saved beforeQuery current operation : com.test.server.model.workflows.WorkSession.checkPoint -> com.test.server.model.checkpoints.CheckPoint; nested exception is java.lang.IllegalStateException: org.hibernate.TransientPropertyValueException: Not-null property references a transient value - transient instance must be saved beforeQuery current operation : com.test.server.model.workflows.WorkSession.checkPoint -> com.test.server.model.checkpoints.CheckPoint",
"path": "/api/v1/workSessions/start"
}
I need to localize exception messages and I'd like to keep the same JSON format of Spring Data REST and take a look how they create the exception object.
I'm looking for the code where the exception is created in source code but I am not able to find that. Maybe ExceptionMessage is useful but it has not the structure of the object that at the end arrive to the user.
Where is the point where the exception is created?
Finally I found a useful link before I didn't see: Modify default JSON error response from Spring Boot Rest Controller.
So the object I was looking for is here: https://github.com/spring-projects/spring-boot/blob/master/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/error/DefaultErrorAttributes.java
there is an answer , from useful link
As described in the documentation on error handling, you can provide
your own bean that implements ErrorAttributes to take control of the
content.
here is example from documentation :
#ControllerAdvice(basePackageClasses = FooController.class)
public class FooControllerAdvice extends ResponseEntityExceptionHandler {
#ExceptionHandler(YourException.class)
#ResponseBody
ResponseEntity<?> handleControllerException(HttpServletRequest request, Throwable ex) {
HttpStatus status = getStatus(request);
return new ResponseEntity<>(new CustomErrorType(status.value(), ex.getMessage()), status);
}
private HttpStatus getStatus(HttpServletRequest request) {
Integer statusCode = (Integer) request.getAttribute("javax.servlet.error.status_code");
if (statusCode == null) {
return HttpStatus.INTERNAL_SERVER_ERROR;
}
return HttpStatus.valueOf(statusCode);
}
}
just inject Locale into handleControllerException method and MessageSource into advice , and in handleControllerException get localize exception messages that you need

Spring boot edit json exception with data from server response

My spring boot application works like a middleman. It waits for a request, then formats this request and sends to the server and returns server response to request sender. However when I get response error response from server (For example with status code 400 Bad Request) I want to modify default spring boot JSON exception body by adding error cause which was returned from server in JSON format.
Response from server:
Http status: 400
{
"type": "InvoiceDto",
"currency": "EUR",
"error_code": "NO_AMOUNT"
"error_message": "amount is not set"
"invoice_status": "FAILED",
"payment_id": "20516324",
"order_id": 1209,
}
Spring boot returns exception:
{
"timestamp": 1493211638359,
"status": 500,
"error": "Internal Server Error",
"exception": "org.springframework.web.client.HttpClientErrorException",
"message": "400 Bad Request",
"path": "/sms"
}
I want to edit spring's exception field "message" with server's returned "error_message" value. But it seems that I can't even get Response body because spring boot automatically throws default exception.
My understanding is that you need to provide your own exception mapper. The one used now is the default ErrorController added by autoconfiguration.
The correct way is to define your own ResponseEntityExceptionHandler
you can read about custom Exceptionmappers here

Proper Handling of PropertyReferenceException for Query Params

In a Spring (Boot) application we're heavily using the Pageable interface and have our controller methods mostly defined like so:
public ResponseEntity<List<Thing>> fetchAll(Pageable pageable) {
Page things = this.thingService.findAll(pageable);
return new ResponseEntity<>(things.getContent(), HttpStatus.OK);
}
When accessing it via the following endpoint:
/api/things/?size=5&page=1&sort=name,asc
If the sort property, name in this case, is misspelled or doesn't exist, a PropertyReferenceException is thrown and a 500 sent back to the user with a message such as:
{
"timestamp": "2017-01-30 13:40:47",
"status": 500,
"error": "Internal Server Error",
"exception": "org.springframework.data.mapping.PropertyReferenceException",
"message": "No property name found for type Thing!",
"path": "/api/things"
}
While this is technically the right error message, it doesn't seem like 500 is the appropriate code to respond with. 5xx level message are typically reserved for server issues and this is technically a user issue so more like a 4xx level message.
Best I can see if that maybe it's just a 400. My question is a) is 400 an appropriate response in this situation and b) is there an elegant way to handle this. My current solution is to catch that Exception in my ControllerAdvice class and just return the 400.

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