使用Jackson解析响应

Question

I am trying to parse the api response using Jackson. getting errors like com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "Health"

I have tried options like

objectMapper.configure(SerializationFeature.WRAP_ROOT_VALUE, false); //with true

I think simple mistake but not able to figure out. please help

Response json:

{
  "Health": {
    "id": "abc_Server",
    "name": "ABC Request Service",
    "status": "GREEN",
    "dependencies": [
      {
        "id": "DB",
        "name": "MySQL",
        "message": "Connection successful.",
        "status": "GREEN"
      }
    ]
  }
}

java pojos

@JsonRootName(value = "Health")
public class HealthResponse {

  private String id;
  private String name;
  private String status;
  private List<Dependencies> dependencies;

  //getter and setter methods
  }
}


public class Dependencies {

  private String id;
  private String name;
  private String message;
  private String status;
  //getter and setter methods
}

main class:

ObjectMapper objectMapper = new ObjectMapper();
try {
InputStream response = healthCheckWebTarget.request(MediaType.APPLICATION_JSON).get(InputStream.class);
HealthResponse healthResponse = objectMapper.readValue(response, HealthResponse.class);
}catch(Exception e){
  //
}

Also tried have a pojo with but did not work

@JsonRootName(value = "Health")
public class Health {

  private HealthResponse health;

 //getter and setter
}

Answer 1

When converting JSON to Java object you're actually deserializing, not serializing. So use this:

objectMapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, true); 

Complete code that's currently working for me (prints abc_Server):

    String json="{\"Health\":{\"id\":\"abc_Server\",\"name\":\"ABCRequestService\",\"status\":\"GREEN\",\"dependencies\":[{\"id\":\"DB\",\"name\":\"MySQL\",\"message\":\"Connectionsuccessful.\",\"status\":\"GREEN\"}]}}";

    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, true);
    try {
        HealthResponse healthResponse = objectMapper.readValue(json, HealthResponse.class);
        System.out.println(healthResponse.getId());
    } catch (Exception e) {
        e.printStackTrace();
    }

And HealthResponse :

@JsonRootName(value = "Health")
class HealthResponse {
    [...]
}

No change in Dependencies

Documentation for UNWRAP_ROOT_VALUE .