Send Status code and message in SpringMVC - spring

I have the following code in my web application:
#ExceptionHandler(InstanceNotFoundException.class)
#ResponseStatus(HttpStatus.NO_CONTENT)
public ModelAndView instanceNotFoundException(InstanceNotFoundException e) {
return returnErrorPage(message, e);
}
Is it possible to also append a status message to the response? I need to add some additional semantics for my errors, like in the case of the snippet I posted I would like to append which class was the element of which the instance was not found.
Is this even possible?
EDIT: I tried this:
#ResponseStatus(value=HttpStatus.NO_CONTENT, reason="My message")
But then when I try to get this message in the client, it's not set.
URL u = new URL ( url);
HttpURLConnection huc = (HttpURLConnection) u.openConnection();
huc.setRequestMethod("GET");
HttpURLConnection.setFollowRedirects(true);
huc.connect();
final int code = huc.getResponseCode();
String message = huc.getResponseMessage();

Turns out I needed to activate custom messages on Tomcat using this parameter:
-Dorg.apache.coyote.USE_CUSTOM_STATUS_MSG_IN_HEADER=true

The message can be in the body rather than in header. Similar to a successful method, set the response (text, json, xml..) to be returned, but set the http status to an error value. I have found that to be more useful than the custom message in header. The following example shows the response with a custom header and a message in body. A ModelAndView that take to another page will also be conceptually similar.
#ExceptionHandler(InstanceNotFoundException.class)
public ResponseEntity<String> handle() {
HttpHeaders responseHeaders = new HttpHeaders();
responseHeaders.set("ACustomHttpHeader", "The custom value");
return new ResponseEntity<String>("the error message", responseHeaders, HttpStatus.INTERNAL_SERVER_ERROR);
}

Related

Get message content from mime message?

I have a java spring integration project that is receving emails through the below code:
ClassPathXmlApplicationContext ac =
new ClassPathXmlApplicationContext(
"/integration/gmail-imap-idle-config.xml");
DirectChannel inputChannel = ac.getBean("receiveChannel", DirectChannel.class);
inputChannel.subscribe(message -> {
org.springframework.messaging.Message<MimeMailMessage> received =
(org.springframework.messaging.Message<MimeMailMessage>) message;
log.info("content" + message);
List<String> sentences = null;
try {
} catch (Exception e) {
}
I get the email, and I can get the subject, but I can never actually extract the message body. How do I do this?
Thank you!
You have to use this option on the channel adapter:
simple-content="true"
See its description:
When 'true', messages produced by the source will be rendered by 'MimeMessage.getContent()'
which is usually just the body for a simple text email. When false (default) the content
is rendered by the 'getContent()' method on the actual message returned by the underlying
javamail implementation.
For example, an IMAP message is rendered with some message headers.
This attribute is provided so that users can enable the previous behavior, which just
rendered the body.
But still it is doubtful, since I see in case of GMail message it is never simple. The content is a MimeMultipart and we need to read its parts to get access to the real body.
So, this is how you should change your code as well:
log.info("content" + ((MimeMultipart) ((MimeMessage) message.getPayload()).getContent()).getBodyPart(0).getContent());

How to write async data to remote endpoint without getting "No suitable writer found exception"?

I have the following controller method:
#PostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, path = "/upload")
public Mono<SomeResponse> saveEnhanced(#RequestPart("file") Mono<FilePart> file) {
return documentService.save(file);
}
which calls a service method where I try to use a WebClient to put some data in another application:
public Mono<SomeResponse> save(Mono<FilePart> file) {
MultipartBodyBuilder bodyBuilder = new MultipartBodyBuilder();
bodyBuilder.asyncPart("file", file, FilePart.class);
bodyBuilder.part("identifiers", "some static content");
return WebClient.create("some-url").put()
.uri("/remote-path")
.syncBody(bodyBuilder.build())
.retrieve()
.bodyToMono(SomeResponse.class);
}
but I get the error:
org.springframework.core.codec.CodecException: No suitable writer found for part: file
I tried all variants of the MultipartBodyBuilder (part, asyncpart, with or without headers) and I cannot get it to work.
Am I using it wrong, what am I missing?
Regards,
Alex
I found the solution after getting a reply from one of the contributes on the Spring Framework Github issues section.
For this to work:
The asyncPart method is expecting actual content, i.e. file.content(). I'll update it to unwrap the part content automatically.
bodyBuilder.asyncPart("file", file.content(), DataBuffer.class)
.headers(h -> {
h.setContentDispositionFormData("file", file.name());
h.setContentType(file.headers().getContentType());
});
If both headers are not set then the request will fail on the remote side, saying it cannot find the form part.
Good luck to anyone needing this!

DELETE in Spring RestTemplate with HttpEntity<List>

I don't know why my code is not working, I've tried with Postman and works fine:
But with RestTemplate I can´t get a response while it´s using the same endpoint... .
ResponseEntity<String> responseMS = template.exchange(notificationRestService, HttpMethod.DELETE, new HttpEntity<NotificationRestDTO[]>(arrNotif), String.class);
I've tried with List instead Array[]
When i made a PUT request it´s works fine but with one object:
ResponseEntity<String> responseMS = template.exchange(notificationRestService, HttpMethod.PUT, new HttpEntity<NotificationRestDTO>(notificationDTO), String.class);
Any help?? Thanks!!
From the comments it became clear that you're expecting it to return a 400 Bad Request response. RestTemplate will see these as "client errors" and it will throw a HttpClientErrorException.
If you want to handle cases like this, you should catch this exception, for example:
try {
ResponseEntity<String> responseMS = template.exchange(notificationRestService, HttpMethod.DELETE, new HttpEntity<NotificationRestDTO[]>(arrNotif), String.class);
} catch (HttpClientErrorException ex) {
String message = ex.getResponseBodyAsString();
}
In this case (since you expect a String), you can use the getResponseBodyAsString() method.
The ResponseEntity will only contain the data in case your request can be executed successfully (2xx status code, like 200, 204, ...). So, if you only expect a message to be returned if the request was not successfully, you can actually do what Mouad mentioned in the comments and you can use the delete() method of the RestTemplate.

How to redirect from spring ajax controller?

I have a controller with #ResponseBody annotation. What I want to do is if this user doesn't exists process user's Id and return a json object. If exists redirect to user page with userInfo. Below code gives ajax error. Is there any way to redirect to user page with userInfo?
#RequestMapping(value = "/user/userInfo", method = {RequestMethod.GET})
#ResponseBody
public String getUserInfo(HttpServletRequest request, HttpServletResponse response, ModelMap modelMap) {
if(...){
.....//ajax return
}else{
modelMap.addAttribute("userInfo", userInfoFromDB);
return "user/user.jsp";
}
}
Well, this method is annotated with #ResponseBody. That means that the String return value will be the body of the response. So here you are just returning "user/user.jsp" to caller.
As you have full access to the response, you can always explicitely do a redirect with response.sendRedirect(...);. It is even possible to explicitely ask Spring to pass userInfoFromDB as a RedirectAttribute through the flash. You can see more details on that in this other answer from me (this latter is for an interceptor, but can be used the same from a controller). You would have to return null to tell spring that the controller code have fully processed the response. Here it will be:
...
}else{
Map<String, Object> flash = RequestContextUtils.getOutputFlashMap(request);
flash.put("userInfo", userInfoFromDB);
response.redirect(request.getContextPath() + "/user/user.jsp");
return null;
}
...
The problem is that the client side expects a string response that will not arrive and must be prepared to that. If it is not, you will get an error client side. The alternative would then be not to redirect but pass a special string containing the next URL:
...
}else{
Map<String, Object> flash = RequestContextUtils.getOutputFlashMap(request);
flash.put("userInfo", userInfoFromDB); // prepare the redirect attribute
return "SPECIAL_STRING_FOR_REDIRECT:" + request.getContextPath() + "/user/user.jsp");
}
and let the javascript client code to process that response and ask for the next page.

Empty request body gives 400 error

My Spring controller method looks something like this:
#RequestMapping(method=RequestMethod.PUT, value="/items/{itemname}")
public ResponseEntity<?> updateItem(#PathVariable String itemname, #RequestBody byte[] data) {
// code that saves item
}
This works fine except when a try to put a zero-length item, then I get an HTTP error: 400 Bad Request. In this case my method is never invoked. I was expecting that the method should be invoked with the "data" parameter set to a zero-length array.
Can I make request mapping work even when Content-Length is 0?
I am using Spring framework version 4.1.5.RELEASE.
Setting a new byte[0] will not send any content on the request body. If you set spring MVC logs to TRACE you should see a message saying Required request body content is missing as a root cause of your 400 Bad Request
To support your case you should make your #RequestBody optional
#RequestMapping(method=RequestMethod.PUT, value="/items/{itemname}")
public ResponseEntity<?> updateItem(#PathVariable String itemname, #RequestBody(required = false) byte[] data) {
// code that saves item
}

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