deserialize inner JSON object

Question

I have a class POJO

Class Pojo {
String id;
String name;
//getter and setter
}

I have a json like

{
    \"response\" : [
          


        

Answer 1

You can use the generic readTree with JsonNode:

ObjectMapper mapper = new ObjectMapper();
JsonNode root = mapper.readTree(json);
JsonNode response = root.get("response");
List<Pojo> list = mapper.readValue(response, new TypeReference<List<Pojo>>() {});

Answer 2

You'll first need to get the array

String jsonStr = "{\"response\" : [ { \"id\" : \"1a\",  \"name\" : \"foo\"},{ \"id\" : \"1b\",\"name\" : \"bar\"  } ]}";
ObjectMapper mapper = new ObjectMapper();
JsonNode node = mapper.readTree(jsonStr);
ArrayNode arrayNode = (ArrayNode) node.get("response");
System.out.println(arrayNode);
List<Pojo> pojos = mapper.readValue(arrayNode.toString(), new TypeReference<List<Pojo>>() {});

System.out.println(pojos);

prints (with a toString())

[{"id":"1a","name":"foo"},{"id":"1b","name":"bar"}] // the json array 
[id = 1a, name = foo, id = 1b, name = bar] // the list contents

Answer 3

Pojo pojo;
json = {
    "response" : [
        {
            "id" : "1a",
            "name" : "foo"
        }, 
        {
            "id" : "1b",
            "name" : "bar"
        }
    ]
}
ObjectMapper mapper = new ObjectMapper();
JsonNode root = objectMapper.readTree(json);
pojo = objectMapper.readValue(root.path("response").toString(),new TypeReference<List<Pojo>>() {});

First, you have to create a JSON node with your JSON file. Now you have a JSON node. You can go to the desired location using path function of JSON node like what I did

root.path("response")

However this will return a JSON tree. To make a String, I have used the toString method. Now, you have a String like below " [ { "id" : "1a", "name" : "foo" }, { "id" : "1b", "name" : "bar" } ] " You can map this String with JSON array as following

String desiredString = root.path("response").toString();
pojos = objectMapper.readValue(desiredString ,new TypeReference<List<Pojo>>() {});