Json文字列とObjectオブジェクトの相互変換のいくつかの方法

Json-Lib、Org.Json、Jackson、Gson、FastJsonの5つの方法でjsonタイプを変換
最も手間のかからない方法だけを列挙した.レプリケーションの状況と速度には関係ありません.
テスト例、Userクラス、属性name、age、location.TOString()を書き換えます.

public class User {
    private String name;
    private Integer age;
    private String location;

    public User() {
    }
    public User(String name) {
        this.name = name;
    }
    public User(String name, Integer age) {
        this.name = name;
        this.age = age;
    }
    public User(String name, Integer age, String location) {
        this.name = name;
        this.age = age;
        this.location = location;
    }

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public String getLocation() {
        return location;
    }
    public void setLocation(String location) {
        this.location = location;
    }

    @Override
    public String toString() {
        return "User{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", location='" + location + '\'' +
                '}';
    }
}

1、Json-Lib
maven依存は以下の通りである、jdk15、jarパケットはjdk 1を区別することに注意する.3とjdk 1.バージョン5

    <dependency>
      <groupId>net.sf.json-libgroupId>
      <artifactId>json-libartifactId>
      <version>2.4version>
      <classifier>jdk15classifier>
    dependency>

テストdemo

import net.sf.json.JSONObject;

public class JsonLibDemo {

    public static void main(String[] args) {
        //    object
        User user = new User("  ",24,"  ");
        System.out.println(user);

        //  json   
        JSONObject jsonObject = JSONObject.fromObject(user);
        String json = jsonObject.toString();
        System.out.println(json);

        //json       
        JSONObject jsonObject1 = JSONObject.fromObject(json);
        User user1 = (User) JSONObject.toBean(jsonObject1,User.class);
        System.out.println(user1);
    }
}

2、org.json
maven依存は以下の通り

    <dependency>
      <groupId>org.jsongroupId>
      <artifactId>jsonartifactId>
      <version>20170516version>
    dependency>

テストdemo

import org.json.JSONObject;

public class OrgJsonDemo {
    public static void main(String[] args) {
        //    object
        User user = new User("  ",24,"  ");
        System.out.println(user);

        //  json   
        String json = new JSONObject(user).toString();
        System.out.println(json);

        //json       
        JSONObject jsonObject = new JSONObject(json);
        String name = jsonObject.getString("name");
        Integer age = jsonObject.getInt("age");
        String location = jsonObject.getString("location");
        User user1 = new User(name,age,location);
        System.out.println(user1);
    }
}

3、Jackson
maven依存

    <dependency>
      <groupId>com.fasterxml.jackson.coregroupId>
      <artifactId>jackson-databindartifactId>
      <version>2.9.0version>
    dependency>

テストdemo

import com.fasterxml.jackson.databind.ObjectMapper;

public class JacksonDemo {
    public static void main(String[] args) {
        //    object
        User user = new User("  ",24,"  ");
        System.out.println(user);

        //  json   
        ObjectMapper mapper = new ObjectMapper();
        try {
            String json = mapper.writeValueAsString(user);
            System.out.println(json);


            //json       
            User user1 = mapper.readValue(json,User.class);
            System.out.println(user1);

        } catch (java.io.IOException e) {
            e.printStackTrace();
        }
    }
}

4、Gson
maven依存

    <dependency>
      <groupId>com.google.code.gsongroupId>
      <artifactId>gsonartifactId>
      <version>2.8.1version>
    dependency>

テストdemo

import com.google.gson.Gson;

public class GsonDemo {
    public static void main(String[] args) {
        //    object
        User user = new User("  ",24,"  ");
        System.out.println(user);

        //  json   
        Gson gson = new Gson();
        String json = gson.toJson(user);
        System.out.println(json);

        //json       
        User user1 = gson.fromJson(json,User.class);
        System.out.println(user1);
    }
}

5、FastJson
maven依存

    <dependency>
      <groupId>com.alibabagroupId>
      <artifactId>fastjsonartifactId>
      <version>1.2.37version>
    dependency>

テストdemo

import com.alibaba.fastjson.JSON;

public class FastJsonDemo {
    public static void main(String[] args) {
        //    object
        User user = new User("  ",24,"  ");
        System.out.println(user);

        //  json   
        String json = JSON.toJSON(user).toString();
        System.out.println(json);

        //json       
        User user1 = JSON.parseObject(json,User.class);
        System.out.println(user1);

    }
}

json-libは時間がかかり、jarパッケージは2010年まで更新されていません.
org.jsonは少し煩わしい
ジャックソン、Gson、FastJsonは一言か二言で済む