使用 Jackson 解析响应

Question

我正在尝试使用 Jackson 解析 api 响应。收到类似 com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException 的错误：无法识别的字段 "Health"

我试过

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

我认为是简单的错误，但无法弄清楚。请帮忙

响应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
}

主要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){
  //
}

也尝试过使用 pojo 但没有成功

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

  private HealthResponse health;

 //getter and setter
}

Answer 1

当将 JSON 转换为 Java 对象时，您实际上是在反序列化，而不是序列化。所以使用这个：

objectMapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, true);

目前为我工作的完整代码（打印 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();
    }

和HealthResponse：

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

Dependencies无变化

UNWRAP_ROOT_VALUE 的文档。

使用 Jackson 解析响应

Parse response using Jackson

java

jaxb

jaxb2

jackson

jackson-databind