Convert json object to java object

Question

I have a request like that:

 let jsonData= {};
 jsonData["className"]= className;
 jsonData["models"]= arr;
 let endPoint= "/classses?classAndModel=" + encodeURIComponent(JSON.stringfy(jsonData));
return $.ajax({
 url: host + endPoint,
 data: data,
 cache: false,
 contentType: false,
 processData: false,
 method: "POST"
 });

I want to convert that json to java object.I tried this one

My rest service is: 
@PostMapping(value=/classes",consumes=MediaType.MULTIPART_FORM_DATA_VALUE)
public ResponseEntity<Void> addClassAndModelMapping(ClassAndModels classAndModels){
}
public class ClassAndModels {
 ClassAndModelResult classAndModel;
 ...getter and setter...
 }
public ClassAndModelResult {
 String className;
 List<String> models;
 ...getter and setters...
 }

I get 400 error.If I change that line ClassAndModelResult classAndModel to String classAndResult.I get response but I want Object type.Do you have any idea?

• Phil Haigh: You need to provide more detail. What does the JSON you are submitting look like? Have you tried creating an instance of ClassAndModels and serialising it to JSON to see how it compares to the JSON you are passing in?
• smichel: You are using @PostMapping annotations. Looks like you are running a Spring (Boot) application, is this correct?
• sneijder10: @smichel yes it is true

Answer 1

The first part of code shows that you are sending data as a query string.

Take a look at https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/bind/annotation/RequestParam.html

But considering the @PostMapping, you should send that data in the request body and do something like this on the server side.

@PostMapping("/classes")
public ResponseEntity<Void> addClassAndModelMapping(@RequestBody ClassAndModels classAndModels){
 //
}

As Phils says, you can add a GetMapping on your controller to see how your ClassAndModels its being serialized

Source: https://spring.io/guides/tutorials/bookmarks/

P.S. Sorry about my english, I'm not a native speaker.

• sneijder10: Yes.Data is being sending as query string.I will add @RequestBody annotation
• sneijder10: Can I use query string and @RequestBody together?
• admlz635: @sneijder10 yes. Try something like public ResponseEntity<Void> addClassAndModelMapping(@RequestBody ClassAndModels classAndModels, @RequestParam(required = false) String testParam). This way you can send host:port/api/classes?testParam=XXXXXXX and the json on the request body
• admlz635: @sneijder10 on ajax part, try dataType: 'json', contentType: 'application/json', and also set data: jsonData

Answer 2

Please try to add @RequestParam annotation or better use classAndModel value as RequestBody similar to the below.And also correct the spelling mistake in the javascript url.

@PostMapping(value = "/classes")
 public ResponseEntity<Void> addClassAndModelMapping(@RequestBody ClassAndModels modal) {
}

• RAJKUMAR NAGARETHINAM: Did you correct that spelling mistake mentioned in the answer?
• RAJKUMAR NAGARETHINAM: Please use application/json in consumes
• RAJKUMAR NAGARETHINAM: Please send that json data along with complete request
• sneijder10: Also I tried this one @RequestMapping(value = "/classes", method = RequestMethod.POST, produces = "application/json", consumes = "application/json")