From a nested JSON String getting a specific key's value

Question

Here I'm having a controller which is of postmapping type. I'm taking the request body as String which a nested JSON. When the controller is being called with the String as request body I want to map that String into a POJO. In that POJO I have fields which are to be mapped from that nested json and also a field which takes the actual String request body as is. Kindly help me how do I map a particular field from that nested json string to the POJO.

The request looks like -

{
    "Application": {
        "DCode": "unsecliverelease",
        "PType": "DA",
        "AId": "230391106",
        "ApNO": "NTFLbjOF9fXI15AF1YiC",
        "crd": {
            "cate": "lion",
            "ProductCode": "lion"
        },
        "ld": {
            "dm": {
                "sn": "3",
                "RandomNumbers": {
                    "RandomNumber01": "319",
                    "RandomNumber02": "731",
                    "RandomNumber03": "520",
                    "RandomNumber04": "102",
                    "RandomNumber05": "678"
                },
                "Request": {
                    "Name": "MSE",
                    "ACount": "1",
                    "BrandInd": "wert",
                    "CID": "123456789",
                    
                }
            }
    }

//controller

@PostMapping(
      value = "/decision",
      produces = MediaType.APPLICATION_JSON_VALUE,
      consumes = MediaType.APPLICATION_JSON_VALUE)
  public ResponseEntity<crdResponse > getDecision(
      @RequestBody final @Valid String request) throws JsonProcessingException {
    crdResponse response =
        crdService.getDec(request);

    return ResponseEntity.ok().body(response);
  }

//POJO

public class CRequestModel {

  @Column(name = "rid")
  @Id
  private String crdRqsId;

  @Column(name = "scode")
  private String scode;

  @Column(name = "cid")
  private Integer cid;

  @Column(name = "RequestNumber")
  private Integer requestNumber;

  @Column(name = "RequestJson")
  private String requestJSON;

  @Column(name = "CreatedAt")
  private Timestamp createdAt;
}

I want to save the whole JSON string into requestJSON field and want to save CID value(from request JSON STRING) into cid field.

Kindly help me with the same. This input JSON String can change so the order in which the CID is there in current JSON String might vary.

Nemanja · Accepted Answer · 2022-07-07 13:15:25Z

Json you posted is not valid. I guess it should look like this :

{
  "Application": {
    "DCode": "unsecliverelease",
    "PType": "DA",
    "AId": "230391106",
    "ApNO": "NTFLbjOF9fXI15AF1YiC",
    "crd": {
      "cate": "lion",
      "ProductCode": "lion"
    },
    "ld": {
      "dm": {
        "sn": "3",
        "RandomNumbers": {
          "RandomNumber01": "319",
          "RandomNumber02": "731",
          "RandomNumber03": "520",
          "RandomNumber04": "102",
          "RandomNumber05": "678"
        },
        "Request": {
          "Name": "MSE",
          "ACount": "1",
          "BrandInd": "wert",
          "CID": "123456789"
        }
      }
    }
  }
}

What you can do is the following:

String json ="{\n" +
                     "  \"Application\": {\n" +
                     "    \"DCode\": \"unsecliverelease\",\n" +
                     "    \"PType\": \"DA\",\n" +
                     "    \"AId\": \"230391106\",\n" +
                     "    \"ApNO\": \"NTFLbjOF9fXI15AF1YiC\",\n" +
                     "    \"crd\": {\n" +
                     "      \"cate\": \"lion\",\n" +
                     "      \"ProductCode\": \"lion\"\n" +
                     "    },\n" +
                     "    \"ld\": {\n" +
                     "      \"dm\": {\n" +
                     "        \"sn\": \"3\",\n" +
                     "        \"RandomNumbers\": {\n" +
                     "          \"RandomNumber01\": \"319\",\n" +
                     "          \"RandomNumber02\": \"731\",\n" +
                     "          \"RandomNumber03\": \"520\",\n" +
                     "          \"RandomNumber04\": \"102\",\n" +
                     "          \"RandomNumber05\": \"678\"\n" +
                     "        },\n" +
                     "        \"Request\": {\n" +
                     "          \"Name\": \"MSE\",\n" +
                     "          \"ACount\": \"1\",\n" +
                     "          \"BrandInd\": \"wert\",\n" +
                     "          \"CID\": \"123456789\"\n" +
                     "        }\n" +
                     "      }\n" +
                     "    }\n" +
                     "  }\n" +
                     "}";
    
    

CRequestModel cRequestModel = new CRequestModel();
    cRequestModel.setRequestJSON(json);

    ObjectMapper mapper = new ObjectMapper();
    JsonNode actualObj = mapper.readTree(json);
    JsonNode cidNode = actualObj.get("Application").get("ld").get("dm").get("Request").get("CID");
    int cid= mapper.treeToValue(cidNode,Integer.class);
    cRequestModel.setCid(cid);

NOTE: The assumption is that the json you get will always have structure above and propeties: ld, dm, Request,CID. (order doesn't matter)

Adrian Mole · Accepted Answer · 2022-07-08 04:36:39Z

1

If you have JSON string that can change, I think you have to create a method that parses that JSON string into a jsonobject and then extract a value from a specified "key".

For example, if you have a JSON string so composed,

{
 "name":"Sam", 
 "surname":"Baudo"
}

String jsonStringInput = "input-json-value"; 
JSONObject json = new JSONObject(jsonStringInput);
String surname = json.getString("surname");

edited Jul 8, 2022 at 4:36

Adrian Mole

52.2k193 gold badges61 silver badges101 bronze badges

answered Jul 7, 2022 at 15:43

Mattia

136 bronze badges

Collectives™ on Stack Overflow

From a nested JSON String getting a specific key's value

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related