Nested JSONObject Deserialize to JSONObject

问题

So I'm working on deserializing a nested JSONObject, but don't want to create a class for each nested object. I was trying to take on of the nested JSONObjects and put it in a JSONObject.

public class ContainerStatus {

@JsonProperty("name")
private String name;
@JsonProperty("state")
private JSONObject state;
@JsonProperty("lastState")
private JSONObject  lastState;
@JsonProperty("ready")
private Boolean ready;
@JsonProperty("restartCount")
private Integer restartCount;
@JsonProperty("image")
private String image;
@JsonProperty("imageID")
private String imageID;
@JsonProperty("containerID")
private String containerID;
@JsonIgnore
private Map<String, Object> additionalProperties = new HashMap<String, Object>();

Using this to deserialize:

 { "containerStatuses": 
        {
            "name": "connect",
            "state": {
                        "terminated": {
                            "exitCode": 1,
                            "reason": "Error",
                            "startedAt": "2019-03-20T15:40:08Z",
                            "finishedAt": "2019-03-20T15:40:50Z",
                            "containerID": "docker://"
                        }
                    },
            "lastState": {},
            "ready": true,
            "restartCount": 0,
            "image": "image",
            "imageID": "docker-pullable://",
            "containerID": "docker://"
        }}

I get unrecognized field "terminated", because of the state JSONObject.

I want a:

JsonObject state = { "terminated": { "exitCode": 1, "reason": "Error", "startedAt": "2019-03-20T15:40:08Z", "finishedAt": "2019-03-20T15:40:50Z", "containerID": "docker://" } }

I can cast it into a generic object, but the format isn't JSON anymore:

@JsonProperty("state")
private Object state;

Gives me this format:
{running={startedAt=2019-03-20T14:53:53Z}}

回答1:

You need to improve a little bit your example:

DeserializationFeature.UNWRAP_ROOT_VALUE, enable this feature to unwrap JSON object.
Add JsonRootName annotation to your POJO class because class name does not match to property containerStatuses.
Use JsonNode which comes from Jackson library instead of JSONObject which comes probably from org.json.

Improved example could look like below:

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonRootName;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonApp {

    public static void main(String[] args) throws Exception {
        String json = "{...}";
        ObjectMapper mapper = new ObjectMapper();
        mapper.enable(DeserializationFeature.UNWRAP_ROOT_VALUE);

        ContainerStatus cs = mapper.readValue(json, ContainerStatus.class);
        System.out.println(cs.getState());
    }
}

@JsonRootName("containerStatuses")
class ContainerStatus {

    @JsonProperty("name")
    private String name;
    @JsonProperty("state")
    private JsonNode state;
    @JsonProperty("lastState")
    private JsonNode lastState;
    @JsonProperty("ready")
    private Boolean ready;
    @JsonProperty("restartCount")
    private Integer restartCount;
    @JsonProperty("image")
    private String image;
    @JsonProperty("imageID")
    private String imageID;
    @JsonProperty("containerID")
    private String containerID;

    // getters, setters, toString
}

Above code prints:

{"terminated":{"exitCode":1,"reason":"Error","startedAt":"2019-03-20T15:40:08Z","finishedAt":"2019-03-20T15:40:50Z","containerID":"docker://"}}

来源：https://stackoverflow.com/questions/55265312/nested-jsonobject-deserialize-to-jsonobject

标签

java

json

serialization

jackson

deserialization