Question 137389 in Json Question posted in
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Json – java deserialize multiple arrays

I have the following json

{   "users": [
    {
      "id": 1,
      "name": "Ash",
      "email": "[email protected]"
    },
    {
      "id": 2,
      "name": "Gary",
      "email": "[email protected]"
    }],   
"pokemon": [
    {
      "userId": 1,
      "name": "Ember",
      "frontImg": "/images/pokemon/local-mon/ember/front.png",
      "backImg": "/images/pokemon/local-mon/ember/back.png",
      "type": "fire",
      "hp": 100,
      "id": 1
    },
    {
      "userId": 1,
      "name": "Draggy",
      "frontImg": "/images/pokemon/local-mon/dragon/front.png",
      "backImg": "/images/pokemon/local-mon/dragon/back.png",
      "type": "dragon",
      "hp": 100,
      "id": 2
    }   ] }

How could I deserialize this into a single object or array containing both the users array of data and the pokemon array of data in Java? Preferably in gson but I’m not opposed to changing libraries.

Tags:

2

Answers


  1. 0

    Add the POJO classes:

    public class Example {

    @SerializedName("users")
    @Expose
    private List<User> users;
    @SerializedName("pokemon")
    @Expose
    private List<Pokemon> pokemon;

    public List<User> getUsers() {
        return users;
    }

    public void setUsers(List<User> users) {
        this.users = users;
    }

    public List<Pokemon> getPokemon() {
        return pokemon;
    }

    public void setPokemon(List<Pokemon> pokemon) {
        this.pokemon = pokemon;
    }
}


public class Pokemon {

    @SerializedName("userId")
    @Expose
    private Integer userId;
    @SerializedName("name")
    @Expose
    private String name;
    @SerializedName("frontImg")
    @Expose
    private String frontImg;
    @SerializedName("backImg")
    @Expose
    private String backImg;
    @SerializedName("type")
    @Expose
    private String type;
    @SerializedName("hp")
    @Expose
    private Integer hp;
    @SerializedName("id")
    @Expose
    private Integer id;

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getFrontImg() {
        return frontImg;
    }

    public void setFrontImg(String frontImg) {
        this.frontImg = frontImg;
    }

    public String getBackImg() {
        return backImg;
    }

    public void setBackImg(String backImg) {
        this.backImg = backImg;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public Integer getHp() {
        return hp;
    }

    public void setHp(Integer hp) {
        this.hp = hp;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

}

public class User {

    @SerializedName("id")
    @Expose
    private Integer id;
    @SerializedName("name")
    @Expose
    private String name;
    @SerializedName("email")
    @Expose
    private String email;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

}

    And then call Example e = new Gson().fromJson(json, Example.class);

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  2. 0

    I suggest using Jackson to read JSON strings into Java Object without defining a suitable class.

    import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import java.io.IOException;

public class JavaApplication {
    public static void main(String[] args) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        mapper.enable(SerializationFeature.INDENT_OUTPUT);

        String json = "{"users":[{"id":1,"name":"Ash","email":"[email protected]"},{"id":2,"name":"Gary","email":"[email protected]"}],"pokemon":[{"userId":1,"name":"Ember","frontImg":"/images/pokemon/local-mon/ember/front.png","backImg":"/images/pokemon/local-mon/ember/back.png","type":"fire","hp":100,"id":1},{"userId":1,"name":"Draggy","frontImg":"/images/pokemon/local-mon/dragon/front.png","backImg":"/images/pokemon/local-mon/dragon/back.png","type":"dragon","hp":100,"id":2}]}";
        JsonNode data = mapper.readTree(json);

        System.out.println(mapper.writeValueAsString(data));
        System.out.println(data.get("users"));
        System.out.println(data.get("users").get(0));
        System.out.println(data.get("pokemon"));
        System.out.println(data.get("pokemon").get(0).get("name"));
    }
}

    The output will be:

    {
  "users" : [ {
    "id" : 1,
    "name" : "Ash",
    "email" : "[email protected]"
  }, {
    "id" : 2,
    "name" : "Gary",
    "email" : "[email protected]"
  } ],
  "pokemon" : [ {
    "userId" : 1,
    "name" : "Ember",
    "frontImg" : "/images/pokemon/local-mon/ember/front.png",
    "backImg" : "/images/pokemon/local-mon/ember/back.png",
    "type" : "fire",
    "hp" : 100,
    "id" : 1
  }, {
    "userId" : 1,
    "name" : "Draggy",
    "frontImg" : "/images/pokemon/local-mon/dragon/front.png",
    "backImg" : "/images/pokemon/local-mon/dragon/back.png",
    "type" : "dragon",
    "hp" : 100,
    "id" : 2
  } ]
}
[{"id":1,"name":"Ash","email":"[email protected]"},{"id":2,"name":"Gary","email":"[email protected]"}]
{"id":1,"name":"Ash","email":"[email protected]"}
[{"userId":1,"name":"Ember","frontImg":"/images/pokemon/local-mon/ember/front.png","backImg":"/images/pokemon/local-mon/ember/back.png","type":"fire","hp":100,"id":1},{"userId":1,"name":"Draggy","frontImg":"/images/pokemon/local-mon/dragon/front.png","backImg":"/images/pokemon/local-mon/dragon/back.png","type":"dragon","hp":100,"id":2}]
"Ember"
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