I have two microservices Microservice A ( context path - /abc ) and microservice B (context path - /def )
Example URLs: test.domain.com/abc/endpoint1 ,test.domain.com/def/endpoint2
In one of the apis of Microservice A ( test.domain.com/abc/endpoint1) internally its making call to Microservice B (/def/endpoint2) -> the prefix for this internal call is generated as follows
(Extract the domain from the request and then append /def/endpoint2 to make a rest call the total url will become as (test.domain.com/def/endpoint2)
Problem : When we are writting unit test cases starting controller level we are using TestRestTemplate
For this testing we need to use http://localhost:portnumber/abc/endpoint1 to test ..
Now the url of the def service also will be derived as http://localhost:portnumber/def/endpoint2
How to mock this response ( Note: We cannot use mock server on same port, we will get port binding exception) . Is there any workaround for the same?
Is there any way to have gateway kind of setup while using TestRestTemplate to route http://localhost:portnumber/def/* calls to get response from mockserver and http://localhost:portnumber/abc/* to make the actual API Service under test?
You could use a ClientHttpRequestInterceptor for this and manipulate the actual URI to call if it matches the path of your second microservice.
This might be a naive protoypish implementation:
public class UrlRewriter implements ClientHttpRequestInterceptor {
#Override
public ClientHttpResponse intercept(HttpRequest httpRequest, byte[] bytes, ClientHttpRequestExecution clientHttpRequestExecution) throws IOException {
try {
if (httpRequest.getURI().toString().contains("/def/abc")) {
HttpRequest modifiedRequest = new MockClientHttpRequest(HttpMethod.GET, new URI("http://localhost:8888/def/abc"));
return clientHttpRequestExecution.execute(modifiedRequest, bytes);
} else {
return clientHttpRequestExecution.execute(httpRequest, bytes);
}
} catch (URISyntaxException e) {
e.printStackTrace();
return null;
}
}
}
And then you can provide a custom bean of type RestTemplateBuilder for your test that is picked up by the TestRestTemplate:
#SpringBootTest(webEnvironment = RANDOM_PORT)
public class TestOne {
#TestConfiguration
static class TestConfig {
#Bean
public RestTemplateBuilder restTemplateBuilder() {
return new RestTemplateBuilder().interceptors(new UrlRewriter());
}
}
#Autowired
private TestRestTemplate testRestTemplate;
#Test
public void test() {
assertNotNull(testRestTemplate);
testRestTemplate.getForObject("/abc/endpoint1", String.class);
}
}
When a Spring bean is annotated with SCOPE_REQUEST, it is created and destroyed every time a HTTP request is received by the servlet. If this bean creation fails, a server error is sent back to the caller.
In this trivial example, the creation of the MyInputs bean is dependent on the contents of the HTTP request.
#Configuration
class ApplicationConfiguration {
#Bean
#Scope(scopeName = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)
public MyInputs myInputs(HttpServletRequest request) {
String header1 = request.getHeader("header1");
if (header1 == null) {
throw new MyException("header1 is missing");
}
return new MyInputs(header1);
}
}
If the HTTP request does not contain a required header, a BeanCreationException will be thrown. This is translated into an unhelpful "500 Internal Server Error" response.
I would like to return a more user-friendly response code and body, for example, a "400 Bad Request" with a helpful message. How do I customize this response translation? I cannot find any lifecycle hooks which will allow this.
Note: This is how the request-scoped bean is consumed:
#RestController
public class MyController {
private final Provider<MyInputs> myInputsProvider;
#Autowired
public MyController(Provider<MyInputs> myInputsProvider) {
this.myInputsProvider = myInputsProvider;
}
#GetMapping("/do-stuff")
public void doStuff() {
// Get the inputs for the current request
MyInputs myInputs = myInputsProvider.get();
// ...
}
}
You can use #ControllerAdvice annotation in order to handle exceptions after are thrown.
Also you need to use #ExceptionHandler in order to handle the exception.
#Order(Ordered.HIGHEST_PRECEDENCE)
#ControllerAdvice
public class GlobalExceptionHandler {
#ExceptionHandler(MyException.class)
public final ResponseEntity<CustomError> handleException(MyException ex, WebRequest request) {
CustomError error = new CustomError();
error.setMessage(ex.getMessage());
error.setStatus(HttpStatus.BAD_REQUEST);
return new ResponseEntity<>(error, null, HttpStatus.BAD_REQUEST);
}
}
I'm working on a web app using Spring MVC and AngularJS, I'm creating a Rest API that returns ResponseEntities that contains JSON strings.
I want to be able when an Exception happens to return a string that contains the error cause to my view and then show this error with a modal in AngularJS, I created a Class with the #ControllerAdvice annotation and in this class I defined a method with my custom exception like this
#ControllerAdvice
public class GlobalExceptionHandlerController {
#ExceptionHandler(PersonalException.class)
public String handleCustomExceptionRazon(PersonalException ex) {
String errorMessage = "custom error";
return errorMessage;
}
}
I have the following interface
public interface ClientDAO {
public void insertCLiente(Client client) throws PersonalException
}
And in my implementation
#Override
public void insertCLiente(Client client) throws PersonalException{
//method implementation
if (searchCLiente(client.name())) {
throw new PersonalException("client aleady exists");
} else {
//method implementation
}
}
My searchClient Method
public boolean searchClient(String name) {
try {
//method implementation
} catch (DataAccessException dataAccessException) {
System.out.println("");
dataAccessException.printStackTrace();
} catch (Exception e) {
System.out.println("");
e.printStackTrace();
}
//method implementation
}
My Client Controller
#Autowired
ClientDAO clientDAO;
#RequestMapping(value = "/client/", method = RequestMethod.POST)
public ResponseEntity<Void> createClient(#RequestBody final String DTOClientData, UriComponentsBuilder ucBuilder) {
//here I parse the JSON data and create my Client object
//here I dont know how can I return the error message
clientDAO.insertClient(client);
}
My custom Exception
public class PersonalException extends Exception {
public PersonalException (String msg) {
super(msg);
}
}
I don't know un my clientController method createClient how can I return an execption of the type PersonalException that I created
//here I dont know how can I return the error message
Just throw the exception from Controller.
#RequestMapping(value = "/client/", method = RequestMethod.POST)
public ResponseEntity<Void> createClient(#RequestBody final String DTOClientData, UriComponentsBuilder ucBuilder) throws PersonalException {
You can return error message in GlobalExceptionHandlerController like this...
/**
* REST exception handlers defined at a global level for the application
**/
#ControllerAdvice
public class RestResponseEntityExceptionHandler extends ResponseEntityExceptionHandler {
#ExceptionHandler(value = { PersonalException.class })
protected ResponseEntity<RestResponse> handleUnknownException(PersonalException ex, WebRequest request) {
LOGGER.error(ex.getMessage(), ex);
return new ResponseEntity<RestResponse>(new RestResponse(Boolean.FALSE, ImmutableList.of("Exception message"), null), HttpStatus.INTERNAL_SERVER_ERROR);
}
Now, you might have noticed that we are not handling the Exception even in the Controller. Instead, we are Throwing it in the declaration hoping that somewhere we have handled this exceptional case gracefully showing the User a nice looking Toaster message.
The question may remains – Where the hell i am handling the Exception? It is handling by the #ExceptionHandler in GlobalExceptionHandlerController .
I'm using Spring boot for hosting a REST API. Instead of having the standard error response I would like to always send a JSON response even if a browser is accessing the URL and as well a custom data structure.
I can do this with #ControllerAdvice and #ExceptionHandler for custom exceptions. But I can't find any good ways of doing this for standard and handled errors like 404 and 401.
Are there any good patterns of how to do this?
For those Spring Boot 2 users who don't wanna use #EnableWebMvc
application.properties
server.error.whitelabel.enabled=false
spring.mvc.throw-exception-if-no-handler-found=true
spring.resources.add-mappings=false
ControllerAdvice
#RestControllerAdvice
public class ExceptionResolver {
#ExceptionHandler(NoHandlerFoundException.class)
#ResponseStatus(HttpStatus.NOT_FOUND)
public HashMap<String, String> handleNoHandlerFound(NoHandlerFoundException e, WebRequest request) {
HashMap<String, String> response = new HashMap<>();
response.put("status", "fail");
response.put("message", e.getLocalizedMessage());
return response;
}
}
Source
It is worked for me in case of #RestControllerAdvice with spring boot
spring.mvc.throw-exception-if-no-handler-found=true
server.error.whitelabel.enabled=false
spring.resources.add-mappings=false
#RestControllerAdvice
public class ErrorHandlerController {
#ExceptionHandler(NoHandlerFoundException.class)
#ResponseStatus(value = HttpStatus.NOT_FOUND )
public String handleNotFoundError(NoHandlerFoundException ex) {
return "path does not exists";
}
}
I've provided the sample solution on how to override response for 404 case. The solution is pretty much simple and I am posting sample code but you can find more details on the original thread: Spring Boot Rest - How to configure 404 - resource not found
First: define Controller that will process error cases and override response:
#ControllerAdvice
public class ExceptionHandlerController {
#ExceptionHandler(NoHandlerFoundException.class)
#ResponseStatus(value= HttpStatus.NOT_FOUND)
#ResponseBody
public ErrorResponse requestHandlingNoHandlerFound() {
return new ErrorResponse("custom_404", "message for 404 error code");
}
}
Second: you need to tell Spring to throw exception in case of 404 (could not resolve handler):
#SpringBootApplication
#EnableWebMvc
public class Application {
public static void main(String[] args) {
ApplicationContext ctx = SpringApplication.run(Application.class, args);
DispatcherServlet dispatcherServlet = (DispatcherServlet)ctx.getBean("dispatcherServlet");
dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);
}
}
Summing up all answers and comment, I think the best way to do this is-
First, tell spring boot to throw exception in case of no handler found in application.properties
spring.mvc.throw-exception-if-no-handler-found=true
Then handle NoHandlerFoundException in your application. I handle this by following way
#ControllerAdvice
public class GlobalExceptionHandler {
#ExceptionHandler(NoHandlerFoundException.class)
public void handleNotFoundError(HttpServletResponse response, NoHandlerFoundException ex) {
ErrorDto errorDto = Errors.URL_NOT_FOUND.getErrorDto();
logger.error("URL not found exception: " + ex.getRequestURL());
prepareErrorResponse(response, HttpStatus.NOT_FOUND, errorDto);
}
}
If you are using Swagger then you can view my other answer to exclude swagger URL from this exception handler
404 error is handled by DispatcherServlet. there is a property throwExceptionIfNoHandlerFound, which you can override.
In Application class you can create a new bean:
#Bean
DispatcherServlet dispatcherServlet () {
DispatcherServlet ds = new DispatcherServlet();
ds.setThrowExceptionIfNoHandlerFound(true);
return ds;
}
...and then catch the NoHandlerFoundException exception in
#EnableWebMvc
#ControllerAdvice
public class GlobalControllerExceptionHandler {
#ExceptionHandler
#ResponseStatus(value=HttpStatus.NOT_FOUND)
#ResponseBody
public ErrorMessageResponse requestHandlingNoHandlerFound(final NoHandlerFoundException ex) {
doSomething(LOG.debug("text to log"));
}
}
You may extend the ResponseEntityExceptionHandler class, which include a lot of common exceptions in a Spring Boot Project. For example, if you wish to use a custom handler for binding exceptions, you may use the following,
#ControllerAdvice
public class MyApiExceptionHandler extends ResponseEntityExceptionHandler {
#Override
public ResponseEntity<Object> handleBindException(BindException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
String responseBody = "{\"key\":\"value\"}";
headers.add("Content-Type", "application/json;charset=utf-8");
return handleExceptionInternal(ex, responseBody, headers, HttpStatus.NOT_ACCEPTABLE, request);
}
}
An other example for the http status 404-Not Found,
#ControllerAdvice
public class MyApiExceptionHandler extends ResponseEntityExceptionHandler {
#Override
public ResponseEntity<Object> handleNoHandlerFoundException(NoHandlerFoundException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
String responseBody = "{\"errormessage\":\"WHATEVER YOU LIKE\"}";
headers.add("Content-Type", "application/json;charset=utf-8");
return handleExceptionInternal(ex, responseBody, headers, HttpStatus.NOT_FOUND, request);
}
}
Regarding the 404 not found exception you should configure the DispatcherServlet to throw and exception if it doesn't find any handlers, instead of the default behavior. For issues with 404, you may also read this question.
I was having the same issue but fixed it using a different method.
To return 404, 401 and other status in a custom response, you can now add the response status to the custom exception class and call it from your exception handler.
With spring utility class AnnotationUtils, you can get the status of any of the defined custom exceptions with the findAnnotation method and it will return the appropriate status using whatever annotation you defined for the exceptions including not found.
Here's my #RestControllerAdvice
#RestControllerAdvice
public class MainExceptionHandler extends Throwable{
#ExceptionHandler(BaseException.class)
ResponseEntity<ExceptionErrorResponse> exceptionHandler(GeneralMainException e)
{
ResponseStatus status = AnnotationUtils.findAnnotation(e.getClass(),ResponseStatus.class);
if(status != null)
{
return new ResponseEntity<>(new ExceptionErrorResponse(e.getCode(),e.getMessage()),status.code());
}
}
CustomParamsException to return Bad request status
#ResponseStatus(value= HttpStatus.BAD_REQUEST)
public class CustomParamsException extends BaseException {
private static final String CODE = "400";
public CustomParamsException(String message) {
super(CODE, message);
}
}
Details not found to return Not Found Status
#ResponseStatus(value= HttpStatus.NOT_FOUND)
public class DetailsNotException extends BaseException {
private static final String CODE = "400";
public DetailsNotException(String message) {
super(CODE, message);
}
}
A GeneralMainException to extend Excetion
public class GeneralMainException extends Exception {
private String code;
private String message;
public GeneralMainException (String message) {
super(message);
}
public GeneralMainException (String code, String message) {
this.code = code;
this.message = message;
}
public String getCode() {
return code;
}
#Override
public String getMessage() {
return message;
}
}
You can decide to handle other system exceptions by including it to the controller advice.
#ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
#ExceptionHandler(Exception.class)
ExceptionErrorResponse sysError(Exception e)
{
return new ExceptionErrorResponse(""1002", e.getMessage());
}
It seems that you need to introduce an appropriately annotated method, e.g. for unsupported media type (415) it will be:
#ExceptionHandler(MethodArgumentNotValidException)
public ResponseEntity handleMethodArgumentNotValidException(HttpServletRequest req, MethodArgumentNotValidException e) {
logger.error('Caught exception', e)
def response = new ExceptionResponse(
error: 'Validation error',
exception: e.class.name,
message: e.bindingResult.fieldErrors.collect { "'$it.field' $it.defaultMessage" }.join(', '),
path: req.servletPath,
status: BAD_REQUEST.value(),
timestamp: currentTimeMillis()
)
new ResponseEntity<>(response, BAD_REQUEST)
}
However it may not be possible since 401 and 404 may be thrown before they reach DispatcherServlet - in this case ControllerAdvice will not work.
You can add custom ErrorPage objects which correlate to the error-page definition in web.xml. Spring Boot provides an example...
#Bean
public EmbeddedServletContainerCustomizer containerCustomizer(){
return new MyCustomizer();
}
// ...
private static class MyCustomizer implements EmbeddedServletContainerCustomizer {
#Override
public void customize(ConfigurableEmbeddedServletContainer container) {
container.addErrorPages(new ErrorPage(HttpStatus.UNAUTHORIZED, "/unauthorized.html"));
container.addErrorPages(new ErrorPage(HttpStatus.NOT_FOUND, "/not-found.html"));
}
}
EDIT: While I think the method above will work if you make the error pages rest controllers, an even easier way would be to include a custom ErrorController like the one below...
#Bean
public ErrorController errorController(ErrorAttributes errorAttributes) {
return new CustomErrorController(errorAttributes);
}
// ...
public class CustomErrorController extends BasicErrorController {
public CustomErrorController(ErrorAttributes errorAttributes) {
super(errorAttributes);
}
#Override
#RequestMapping(value = "${error.path:/error}")
#ResponseBody
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
ResponseEntity<Map<String, Object>> error = super.error(request);
HttpStatus statusCode = error.getStatusCode();
switch (statusCode) {
case NOT_FOUND:
return getMyCustomNotFoundResponseEntity(request);
case UNAUTHORIZED:
return getMyCustomUnauthorizedResponseEntity(request);
default:
return error;
}
}
}
Please see Spring Boot REST service exception handling. It shows how to tell the dispatcherservlet to emit exceptions for "no route found" and then how to catch those exceptions. We (the place I work) are using this in production for our REST services right now.
Starting with Spring version 5 can use class ResponseStatusException:
#GetMapping("example")
public ResponseEntity example() {
try {
throw new MyException();
} catch (MyException e) {
throw new ResponseStatusException(HttpStatus.INTERNAL_SERVER_ERROR, "My Exception", e);
}
}
I wanted to have the same error format (json) structure across all possible error scenarios, so I just registered my own ErrorController reusing the code from AbstractErrorController:
#Controller
#RequestMapping(path = "/error", produces = MediaType.APPLICATION_JSON_VALUE)
#ResponseBody
public class ErrorController extends AbstractErrorController {
public ErrorController(ErrorAttributes errorAttributes, ObjectProvider<ErrorViewResolver> errorViewResolvers) {
super(errorAttributes, errorViewResolvers.orderedStream().collect(Collectors.toUnmodifiableList()));
}
#RequestMapping
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
final var status = getStatus(request);
if (status == HttpStatus.NO_CONTENT) {
return new ResponseEntity<>(status);
}
return new ResponseEntity<>(getErrorAttributes(request, ErrorAttributeOptions.defaults()), status);
}
#Override
public String getErrorPath() {
return null;
}
}
with this you dont need any controller advice, all errors go to error method by default
I want to perform a test on a controller method which throws an exception. The method is something like this:
#RequestMapping("/do")
public ResponseEntity doIt(#RequestBody Request request) throws Exception {
throw new NullPointerException();
}
When I try to test this method with following code part,
mockMvc.perform(post("/do")
.contentType(MediaType.APPLICATION_JSON)
.content(JSON.toJson(request)))
NestedServletException is thrown from Spring libraries. How can I test that NullPointerException is thrown instead of NestedServletException?
Our solution is rather a workaround: The exception is caught in advice and error body is returned as HTTP response. Here is how the mock works:
MockMvc mockMvc = MockMvcBuilders.standaloneSetup(controller)
.setHandlerExceptionResolvers(withExceptionControllerAdvice())
.build();
private ExceptionHandlerExceptionResolver withExceptionControllerAdvice() {
final ExceptionHandlerExceptionResolver exceptionResolver = new ExceptionHandlerExceptionResolver() {
#Override
protected ServletInvocableHandlerMethod getExceptionHandlerMethod(final HandlerMethod handlerMethod, final Exception exception) {
Method method = new ExceptionHandlerMethodResolver(TestAdvice.class).resolveMethod(exception);
if (method != null) {
return new ServletInvocableHandlerMethod(new TestAdvice(), method);
}
return super.getExceptionHandlerMethod(handlerMethod, exception);
}
};
exceptionResolver.afterPropertiesSet();
return exceptionResolver;
}
Advice class:
#ControllerAdvice
public class TestAdvice {
#ExceptionHandler(Exception.class)
#ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
public Object exceptionHandler(Exception e) {
return new HttpEntity<>(e.getMessage());
}
}
After than, following test method passes successfully:
#Test
public void testException
mockMvc.perform(post("/exception/path"))
.andExpect(status().is5xxServerError())
.andExpect(content().string("Exception body"));
}
Easier way is to inject #ExceptionHandler into your Spring Test Context or it throws exception right in MockMvc.perform() just before .andExpect().
#ContextConfiguration(classes = { My_ExceptionHandler_AreHere.class })
#AutoConfigureMockMvc
public class Test {
#Autowired
private MockMvc mvc;
#Test
public void test() {
RequestBuilder requestBuilder = MockMvcRequestBuilders.post("/update")
.param("branchId", "13000")
.param("triggerId", "1");
MvcResult mvcResult = mvc.perform(requestBuilder)
.andExpect(MockMvcResultMatchers.status().is4xxClientError())
.andExpect(MockMvcResultMatchers.content().contentType(MediaType.APPLICATION_JSON_UTF8))
.andExpect(__ -> Assert.assertThat(
__.getResolvedException(),
CoreMatchers.instanceOf(SecurityException.class)))
.andReturn();
}
That way MvcResult.getResolvedException() holds #Controller's exception!
https://stackoverflow.com/a/61016827/173149