Cannot deserialize JSONObject (inside of JSONArray) in Java Spring

Question

So, I have this method here:

@RequestMapping(value = "/getFields", produces = "application/json")
public Response getFields(@RequestParam(value = "id") int id)

and I have a class which extends Response. In this class, I have defined a JSONArray, in which I put a JSONObject through a method which wraps JSONArray.put(JSONObject obj).

At the end of my getRegistrationFields I return the instantiated object of the class extending Response.

This way, Spring should return the JSONArray contained in this object, and I should see it when I call "/getFields" REST method.

However, it gives me an Error 500

Could not write content: No serializer found for class org.json.JSONObject and no properties discovered to create BeanSerializer

Is there a quick way to fix this?

score 1 · Accepted Answer · answered Oct 06 '16 at 12:05

Try to use the next dependency (or jar:

<dependency>
        <groupId>com.fasterxml.jackson.datatype</groupId>
        <artifactId>jackson-datatype-jsr310</artifactId>
        <version>${jackson.version}</version>
</dependency>

If doesn't help, try to use Jackson ArrayNode and ObjectNode instead of JSONArray and JSONObject.

   ObjectMapper mapper = new ObjectMapper();
    ArrayNode arrayNode = mapper.createArrayNode();
    Object obj = new Object();
    arrayNode.addPOJO(obj);
    arrayNode.add(mapper.createObjectNode().put("field1", "Hello Stack!"));

Please see the link to the doc: http://fasterxml.github.io/jackson-databind/javadoc/2.0.0/com/fasterxml/jackson/databind/node/ArrayNode.html

The ArrayNode and ObjectNode did the job! Thank you. – Andrea Borzi Oct 06 '16 at 14:05 — Andrea Borzi, Oct 06 '16 at 14:05

score 0 · Answer 2 · answered Oct 06 '16 at 12:06

Have To Accept it first as a Json Array ,then while reading its Object have to use Object Mapper.readValue ,because Json Object Still in String .

List<User> list = new ArrayList<User>();
JSONArray jsonArr = new JSONArray(response);

for (int i = 0; i < jsonArr.length(); i++) {
    JSONObject jsonObj = jsonArr.getJSONObject(i);
    ObjectMapper mapper = new ObjectMapper();
    User usr = mapper.readValue(jsonObj.toString(), User.class);      
    list.add(usr);
}

Cannot deserialize JSONObject (inside of JSONArray) in Java Spring

2 Answers2