get modelandview object in another controller - java

I am working to pass data from one controller to another.
I have one class that is annotated with #ControllerAdvice that is used to handle all exception of application.
I am processing exception and adding them to custom class then in ModelAndView I am adding that and passing to another controller using redirect.
And in that controller I want that added object but I don't have much idea about it how to get that object. I have tried some trick but did not get success.
Code:
ExceptionHandler class:
#ControllerAdvice
public class DefaultExceptionHandler {
#Autowired
private CPro cPro;
private static final Logger LOG = LoggerFactory.getLogger(DefaultExceptionHandler.class);
#RequestMapping(produces = {MediaType.APPLICATION_JSON_VALUE})
#ExceptionHandler(Exception.class)
#ResponseStatus(value = INTERNAL_SERVER_ERROR)
#ResponseBody
public ModelAndView handleException(Exception ex) {
ModelAndView modelAndView = new ModelAndView("redirect:/");
String exceptionType = ex.getClass().getSimpleName();
DefaultExceptionHandler.LOG.error("Internal Server Exception", ex);
ErrorResponse response = new ErrorResponse();
if (ex.getCause() != null) {
response.addSimpleError(exceptionType, ex.getCause().getMessage(), cPro.getProName());
} else {
response.addSimpleError(exceptionType, ex.getMessage(), cPro.getProName());
}
modelAndView.addObject("processingException", response);
return modelAndView;
}
}
my home controller:
#RequestMapping(value = "/", method = RequestMethod.GET)
public String getHomePage(#ModelAttribute("processingException") ErrorResponse errorResponse, Model model) {
// I want to get object data of processingException added in exception handler using ModelAndView
model.addAttribute("processingException", errorResponse.getError() == null ? null : errorResponse);
return "upscale"; //here upscale.html redirection
}
Does anyone have idea that how to get that object data in my controller ?
Thanks.


After a lot googling and searching various forums and article, I found some solution. I have combined data and code of various forums I have made my requirement fulfill.
We can use FlashMap for that. Just get context of request and add FlashMap and add other data to FlashMap as well.
Code:
#ControllerAdvice
public class DefaultExceptionHandler {
#Autowired
private CPro cPro;
private static final Logger LOG = LoggerFactory.getLogger(DefaultExceptionHandler.class);
#ExceptionHandler(Exception.class)
public String handleException(Exception ex, HttpServletRequest request) throws IOException {
DefaultExceptionHandler.LOG.error("Internal Server Exception", ex);
String exceptionType = ex.getClass().getSimpleName();
ErrorResponse response = new ErrorResponse();
if (ex.getCause() != null) {
response.addError(exceptionType, ex.getCause().getMessage(), cPro.getProName());
} else {
response.addError(exceptionType, ex.getMessage(), cPro.getProName());
}
FlashMap outputFlashMap = RequestContextUtils.getOutputFlashMap(request);
if (outputFlashMap != null) {
outputFlashMap.put("processingException", response);
}
return "redirect:/";
}
}
and other hand, in controller use ModelAttribute to get data that is sent from exception handler method.
code:
#RequestMapping(value = "/", method = RequestMethod.GET)
public String getHomePage(Model model, #ModelAttribute("processingException") Object processingException) {
if (processingException instanceof ErrorResponse) {
model.addAttribute("processingException", ((ErrorResponse) processingException).getError());
} else {
model.addAttribute("processingException", null);
}
return "upscale"; //here upscale.html redirection
}
After all bingo.. Done my work.
If anyone have still better idea on it then still welcome..
Thanks guys.


You could make a workaround like this:
public ModelAndView handleException(Exception ex, HttpServletRequest req) {
//...
ModelAndView modelAndView = new ModelAndView("forward:/");
//...
req.setAttribute("processingException", response);
Then in your Controller Method you have access to HttpServletRequest and get the Attribute (Object):
public String getHomePage(#ModelAttribute("processingException", HttpServletRequest req)
{
//....
req.getAttribute("processingException");

Related

Spring MVC default #RequestMapping to catch unmatched URL

I have this Controller
#Controller
#RequestMapping(value = "/v1.0/user")
public class UserController {
#RequestMapping(value = "/findOne/{id}", method = RequestMethod.GET)
public #ResponseBody String findOne(#PathVariable("id") Integer id) {
log.info("findOne");
return "found URL";
}
}
Which will match the URL: http://localhost:8080/v1.0/user/findOne/4
But if my path varibale is not correct: http://localhost:8080/v1.0/user/findOne/4A
The I get nothing. Not even an error. It's as if Spring swallowed the URL.
I added
#RequestMapping(value = "/.*", method = RequestMethod.GET)
public #ResponseBody String redirectEverythingOtherThanTest(){
log.info("no url matched");
return "badly formed URL for Users";
}
Again I get nothing. What I'm trying to accomplish is for each Controller to have a unique message when the URL does not match.

In the end in each of my Controller classes I added
#ExceptionHandler(Exception.class)
public #ResponseBody String handleException(Exception e, HttpServletRequest request, HttpServletResponse response) {
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
return e.getMessage();
}
And this will catch all exceptions and I can treat it as a catch all.

Return empty JSON from spring controller for void response

I'm using Java 8, Tomcat 8, Spring-WebMVC 4.2.2.RELEASE, FasterXML 2.6.3.
I have the following method in my controller
#RequestMapping(method = RequestMethod.POST)
#ResponseBody
public void updateCurrentUserDetails(#RequestBody final UserDTO userDTO) {
final UserWithId user = SecurityUtil.getCurrentUser();
this.userAccountService.updateUserDetails(user.getUserId(), user.getUsername(), userDTO);
}
This method returns void which resolves in an empty (0 byte) response. However the clients connecting to the server always expect JSON reponses even, if its an empty response.
So I would like to configure Spring/Jackson to return {} (2 byte) in that case.
I already thought about returning new Object() everywhere in the calls that would return void otherwise but IMO this is a dirty soution and there must be something better.

There shouldn't be any need to do all that. You can just use a 204 response code, which is made for the situation you are describing. You don't even need the ResponseBody annotation, just use:
#RequestMapping(method = RequestMethod.POST)
#ResponseStatus(HttpStatus.NO_CONTENT)
public void updateCurrentUserDetails(#RequestBody final UserDTO userDTO) {
final UserWithId user = SecurityUtil.getCurrentUser();
this.userAccountService.updateUserDetails(user.getUserId(), user.getUsername(), userDTO);
}
204 response code:
The 204 (No Content) status code indicates that the server has
successfully fulfilled the request and that there is no additional
content to send in the response payload body.

Its quite easy.
Just add the following to your spring xml/java config
<mvc:interceptors>
<bean class="de.st_ddt.util.VoidResponseHandlerInterceptor" />
</mvc:interceptors>
And add this class to your classpath
public class VoidResponseHandlerInterceptor extends HandlerInterceptorAdapter {
private static final String voidResponse = "{}";
#Override
public void postHandle(final HttpServletRequest request, final HttpServletResponse response, final Object handler,
final ModelAndView modelAndView) throws IOException {
// Returned void?
if (!response.isCommitted()) {
// Used ModelAndView?
if (modelAndView != null) {
return;
}
// Access static resource?
if (DefaultServletHttpRequestHandler.class == handler.getClass()) {
return;
}
response.setStatus(200);
response.setCharacterEncoding("UTF-8");
response.setContentType("application/json");
try (final Writer writer = response.getWriter()) {
writer.write(voidResponse);
}
response.flushBuffer();
}
}
}

Spring boot 404 error custom error response ReST

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

ExtJS how to get exception from spring conrolerAdvice handler

On the server I am handling exceptions globally using #ControllerAdvice
CODE:
#ControllerAdvice
#EnableWebMvc
public class GlobalExeptionHandler
{
public static final String DEFAULT_ERROR_VIEW = "error";
#ExceptionHandler(value = {Exception.class,RuntimeException.class})
public ModelAndView defaultErrorHandler (HttpServletRequest request, Exception e)
{
ModelAndView mav = new ModelAndView(DEFAULT_ERROR_VIEW);
mav.addObject("datetime", new Date());
mav.addObject("exception", e);
mav.addObject("url", request.getRequestURL());
return mav;
}
#ExceptionHandler(value = {UnableToSaveException.class})
public ModelAndView saveExceptionHandler (HttpServletRequest request, UnableToSaveException e)
{
ModelAndView mav = new ModelAndView(DEFAULT_ERROR_VIEW);
mav.addObject("errCode", e.getErrCode());
mav.addObject("errMsg", e.getErrMsg());
return mav;
}
}
I know that using ExtJS on client I can catch exception using this code:
Ext.Ajax.on('requestexception', function(conn, response, options, eOpts)
{
...
}
I want to rise dialog with error Message which I want to get from ModelAndView which is returned in spring, but I do not know how to get it. Can someone tell me how, or say if I doing something wrong?

How to return 404 response status in Spring Boot #ResponseBody - method return type is Response?

I'm using Spring Boot with #ResponseBody based approach like the following:
#RequestMapping(value = VIDEO_DATA_PATH, method = RequestMethod.GET)
public #ResponseBody Response getData(#PathVariable(ID_PARAMETER) long id, HttpServletResponse res) {
Video video = null;
Response response = null;
video = videos.get(id - 1);
if (video == null) {
// TODO how to return 404 status
}
serveSomeVideo(video, res);
VideoSvcApi client = new RestAdapter.Builder()
.setEndpoint("http://localhost:8080").build().create(VideoSvcApi.class);
response = client.getData(video.getId());
return response;
}
public void serveSomeVideo(Video v, HttpServletResponse response) throws IOException {
if (videoDataMgr == null) {
videoDataMgr = VideoFileManager.get();
}
response.addHeader("Content-Type", v.getContentType());
videoDataMgr.copyVideoData(v, response.getOutputStream());
response.setStatus(200);
response.addHeader("Content-Type", v.getContentType());
}
I tried some typical approaches as:
res.setStatus(HttpStatus.NOT_FOUND.value());
new ResponseEntity(HttpStatus.BAD_REQUEST);
but I need to return Response.
How to return here 404 status code if video is null?

This is very simply done by throwing org.springframework.web.server.ResponseStatusException:
throw new ResponseStatusException(
HttpStatus.NOT_FOUND, "entity not found"
);
It's compatible with #ResponseBody and with any return value. Requires Spring 5+

Create a NotFoundException class with an #ResponseStatus(HttpStatus.NOT_FOUND) annotation and throw it from your controller.
#ResponseStatus(code = HttpStatus.NOT_FOUND, reason = "video not found")
public class VideoNotFoundException extends RuntimeException {
}

Your original method can return ResponseEntity (doesn't change your method behavior):
#RequestMapping(value = VIDEO_DATA_PATH, method = RequestMethod.GET)
public ResponseEntity getData(#PathVariable(ID_PARAMETER) long id, HttpServletResponse res{
...
}
and return the following:
return new ResponseEntity(HttpStatus.NOT_FOUND);

You can just set responseStatus on res like this:
#RequestMapping(value = VIDEO_DATA_PATH, method = RequestMethod.GET)
public ResponseEntity getData(#PathVariable(ID_PARAMETER) long id,
HttpServletResponse res) {
...
res.setStatus(HttpServletResponse.SC_NOT_FOUND);
// or res.setStatus(404)
return null; // or build some response entity
...
}

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