Getting Form data in Spring REST controller - alternatives - java

I have a spring rest controller and I want to properly receive a form-data from my UI. Do you know any other way of getting form-data besides of my proposal?
I have managed to get the data using #RequestPart("fields-name") but its not optimal since I need to get the form-data and send it as it is to another rest controller.
MyResponse addAttachment(#RequestParam("file") MultipartFile file, #RequestParam("note") String note);
In the end I want the flow to look like this:
|UI|--(form-data)---> |Java-Spring A| ---(form-data)----> |Java-Spring B|--(file-from-form)--> |DB|
currently it looks like that:
In spring A: myResponse addAttachment(#ModelAttribute AttachmentForm form)
In spring B: myResponse addAttachment(#ModelAttribute MultiValueMap<String, Object> form)
From A->B I do the following:
MultiValueMap<String, Object> valueMap = new LinkedMultiValueMap<>();
valueMap.add("note", form.getNote());
valueMap.add("file_name", file.getOriginalFilename()); //Send the file as bytes array
valueMap.add("files", new ByteArrayResource(file.getBytes()));
resttemplate.sendhttpcall(valueMap);// helper function to send between A->B
After sending the form data ( as a model object AttachmentForm) I parse it before sending it from A to B. one step after restTemplate.exchange it gets to Spring B and I get the following exception (in my Expception controller class):
"java.lang.IllegalStateException: No primary or default constructor found for interface org.springframework.util.MultiValueMap"
Thanks

Related

Spring Controller GET/POST/PUT to another interface

I am using React as frontend and Java Spring Boot as backend.
React sends JSON form data as GET/PUT/POST requests to my backend url (http://localhost:8080/test). Now, I wan't to send this JSON forward to another interfaces GET endpoint (https://another/interface/add?id={id}). This interface then queries database based on the id and answers 200 OK message with a JSON reply which I need to display (send back to frontend).
1. What is the correct way of sending a request to another interface from Spring Boot backend? In the same method I catched the frontends data?
2. I also have to set HTTP headers to the GET request, how would I go on about this?
Example of how Frontend is sending an id field as a JSON to backend:
React POST
addId = async (data) => {
return this.post(/localhost:8080/test/id, data)
}
Example of how Backend is receiving the id field:
Spring Boot POST
#PostMapping("test/id")
public String test(#RequestBody String id) {
return id;
}
As I understand you want to get data from backend with json body and httpstatuscode 200 . Am i right?
May be you can try this
#GetMapping(/interface/add)
public ResponseEntity<?> test(#RequestParam("id") String id){
//write code you want
return ResponseEntity.status(HttpStatus.OK).body("string" or dto possible);
}
ResponseEntity send body with httpstatus code and if you want to send requestparam you set #RequestParam annotation to set .
When I do project with springboot and react. I use json type to exchange data. And Most Services usually exchange data with json data type.
2.I confused about this Question if you send data React to springboot your code is right
Axios.get("localhost....", data) you can change http type with
Axios.(get, post, delete)

How to pass a json object as a parameter in a REST request URL with Springboot

I have looked at the various answers and they do not resolve my issue. I have a very specific client need where I cannot use the body of the request.
I have checked these posts:
Trying to use Spring Boot REST to Read JSON String from POST
Parsing JSON in Spring MVC using Jackson JSON
Pass JSON Object in Rest web method
Note: I do encode the URI.
I get various errors but illegal HTML character is one. The requirement is quite simple:
Write a REST service which accepts the following request
GET /blah/bar?object=object11&object=object2&...
object is a POJO that will come in the following JSON format
{
"foo": bar,
"alpha": {
"century": a,
}
}
Obviously I will be reading in a list of object...
My code which is extremely simplified... as below.
#RequestMapping(method=RequestMethod.GET, path = "/test")
public Greeting test(#RequestParam(value = "object", defaultValue = "World") FakePOJO aFilter) {
return new Greeting(counter.incrementAndGet(), aFilter.toString());
}
I have also tried to encapsulate it as a String and convert later which doesnt work either.
Any suggestions? This should really be extremely simple and the hello world spring rest tut should be a good dummy test framework.
---- EDIT ----
I have figured out that there is an underlying with how jackson is parsing the json. I have resolved it but will be a write up.. I will provide the exact details after Monday. Short version. To make it work for both single filter and multiple filters capture it as a string and use a json slurper
If you use #RequestParam annotation to a Map<String, String> or MultiValueMap<String, String> argument, the map will be populated with all request parameters you specified in the URL.
#GetMapping("/blah/bar")
public Greeting test(#RequestParam Map<String, String> searchParameters) {
...
}
check the documentation for a more in depth explanation.

Spring boot PutMapping with Enum as RequestBody issue

I have a spring boot controller endpoint as follows.
#PutMapping("/manage/{id}")
public ResponseEntity<Boolean> manage(#PathVariable Long id, #RequestBody Type type) {
...
}
Where Type is an Enum as follows.
public enum Type {
ONE,
TWO
}
ISSUE 1: When I test this controller, I have to send the content as "ONE" instead of ONE for a successful invocation. i.e. it works with the following code.
mvc.perform(put("/api/manage/1")
.contentType(MediaType.APPLICATION_JSON_VALUE)
.content("\"" + Type.ONE + '\"'))
.andExpect(status().isOk());
It does not work with
mvc.perform(put("/api/manage/1")
.contentType(MediaType.APPLICATION_JSON_VALUE)
.content(Type.ONE.name()))
.andExpect(status().isOk());
ISSUE 2: I am not able to invoke this method from the Angular service.
this.http.put<string>('/api/manage/' + id, type)
gives me
org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported
Everything works when I add the Enum to a Dto and send an object from the client. But due to some business requirements, I want to use the current structure itself. i.e the Enum as a RequestBody.
UPDATE
I also tried to change the controller method structure to
#PutMapping(value = "/manage/{id}", consumes = MediaType.TEXT_PLAIN_VALUE)
I get the following error.
Content type 'text/plain' not supported
Both issues stem from trying to use a JSON endpoint as a plain text endpoint.
Ad 1, ONE is invalid JSON ("ONE" is valid)
Ad 2, when you just post a string, it is sent as text/plain and the endpoint complains.
Probably adding consumes="text/plain" to your #PutMapping will solve the problem, but frankly - I am not sure if string/enum mappings work out-of-the-box in the hodge-podge that is spring boot.

Spring MVC Override Received Content Type

I'm working on a Spring MVC application and have a client that I have no control over. This client is POSTing JSON data but transmitting a application/x-www-form-urlencoded header. Spring naturally trusts this header and tries to receive the data but can't because its JSON. Has anyone had experience overriding the header that Spring receives or just specifying exactly what type of data is coming, regardless of the headers?
You can do two things;
Change the client to send the Content-Type:
application/json header
Write a Servlet Filter or Spring Interceptor which is on top of the Spring Controller and checks for the header Content-Type. If it is not application/json then it changes it to application/json.
Why don't you write a separate controller to handle application/x-www-form-urlencoded requests. If the request is a valid JSON, then you can parse it and forward it to to appropriate service.
This way you can also handle a case in future where you get request of same type which is not a valid JSON.
#RequestMapping(value = "/handleURLEncoded", method = RequestMethod.POST, consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
public #ResponseBody Object handleURLEncoded(HttpEntity<String> httpEntity) {
String json = httpEntity.getBody();
//now you have your request as a String
//you can manipulate it in any way
if(isJSONValid(json)) {
JSONObject jsonObj = new JSONObject(json);
//forward request or call service directly from here
//...
}
//other cases where it's not a valid JSON
}
Note: isJSONValid() method copied from this answer

Pass form data from Spring Controller to an external endpoint

My issue:
Having a form in a simple HTML, with action="/myController".
I need to send the form data to my Controller and from there I need to make another POST to an external Controller.
<form method="post" action="/myController">
<textarea name="data"></textarea>
</form>
And my Spring Controller looks something like this:
#RequestMapping(method = RequestMethod.GET, value = "/myController")
#ResponseBody
public String myController(#RequestBody MultiValueMap<String, String[]> formData) {
RestTemplate rest = new RestTemplate();
ResponseEntity<String> response = rest.postForEntity("urlPath", formData, String.class);
String manipulatedResult = manipulateResult(response.getBody());
return manipulatedResult;
}
I need to pass form data, to my controller, it should send form data further to the "urlPath" and recieve a response. I need to manipulate that response and return a result.
My question is, how to send the form data further, without manipulating the request?
Thanks in advance.
Your Response doesn't need to be a String it can be a well formed java object. In this case i do not see any issue returning ResponseEntity object without converting this into String.
#ResponseBody will convert returned java object to JSON/Xml based response to outside world.
you can use ModelAndView class.
Refer the following link: http://docs.spring.io/spring-framework/docs/2.5.6/api/org/springframework/web/portlet/ModelAndView.html

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