Java实现Json字符串与Object对象相互转换的方式总结

这篇文章主要介绍了Java实现Json字符串与Object对象相互转换的方式,结合实例形式总结分析了java基于Json-Lib、Org.Json、Jackson、Gson、FastJson五种方式转换json类型相关操作技巧,需要的朋友可以参考下

本文实例总结了Java实现Json字符串与Object对象相互转换的方式。分享给大家供大家参考，具体如下：

Json-Lib、Org.Json、Jackson、Gson、FastJson五种方式转换json类型

只列举了最省事的方式。不涉及复制情况和速度。

测试用例，一个User类，属性name，age，location。重写toString()。

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依赖如下，需注意<classifier>jdk15</classifier>，jar包区分jdk1.3和jdk1.5版本

<dependency>
 <groupId>net.sf.json-lib</groupId>
 <artifactId>json-lib</artifactId>
 <version>2.4</version>
 <classifier>jdk15</classifier>
</dependency>

测试demo

import net.sf.json.JSONObject;
public class JsonLibDemo {
  public static void main(String[] args) {
    //创建测试object
    User user = new User("李宁",24,"北京");
    System.out.println(user);
    //转成json字符串
    JSONObject jsonObject = JSONObject.fromObject(user);
    String json = jsonObject.toString();
    System.out.println(json);
    //json字符串转成对象
    JSONObject jsonObject1 = JSONObject.fromObject(json);
    User user1 = (User) JSONObject.toBean(jsonObject1,User.class);
    System.out.println(user1);
  }
}

2、org.json

maven依赖如下

<dependency>
 <groupId>org.json</groupId>
 <artifactId>json</artifactId>
 <version>20170516</version>
</dependency>

测试demo

import org.json.JSONObject;
public class OrgJsonDemo {
  public static void main(String[] args) {
    //创建测试object
    User user = new User("李宁",24,"北京");
    System.out.println(user);
    //转成json字符串
    String json = new JSONObject(user).toString();
    System.out.println(json);
    //json字符串转成对象
    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依赖

<dependency>
 <groupId>com.fasterxml.jackson.core</groupId>
 <artifactId>jackson-databind</artifactId>
 <version>2.9.0</version>
</dependency>

测试demo

import com.fasterxml.jackson.databind.ObjectMapper;
public class JacksonDemo {
  public static void main(String[] args) {
    //创建测试object
    User user = new User("李宁",24,"北京");
    System.out.println(user);
    //转成json字符串
    ObjectMapper mapper = new ObjectMapper();
    try {
      String json = mapper.writeValueAsString(user);
      System.out.println(json);
      //json字符串转成对象
      User user1 = mapper.readValue(json,User.class);
      System.out.println(user1);
    } catch (java.io.IOException e) {
      e.printStackTrace();
    }
  }
}

4、Gson

maven依赖

<dependency>
 <groupId>com.google.code.gson</groupId>
 <artifactId>gson</artifactId>
 <version>2.8.1</version>
</dependency>

测试demo

import com.google.gson.Gson;
public class GsonDemo {
  public static void main(String[] args) {
    //创建测试object
    User user = new User("李宁",24,"北京");
    System.out.println(user);
    //转成json字符串
    Gson gson = new Gson();
    String json = gson.toJson(user);
    System.out.println(json);
    //json字符串转成对象
    User user1 = gson.fromJson(json,User.class);
    System.out.println(user1);
  }
}

5、FastJson

maven依赖

<dependency>
 <groupId>com.alibaba</groupId>
 <artifactId>fastjson</artifactId>
 <version>1.2.37</version>
</dependency>

测试demo

import com.alibaba.fastjson.JSON;
public class FastJsonDemo {
  public static void main(String[] args) {
    //创建测试object
    User user = new User("李宁",24,"北京");
    System.out.println(user);
    //转成json字符串
    String json = JSON.toJSON(user).toString();
    System.out.println(json);
    //json字符串转成对象
    User user1 = JSON.parseObject(json,User.class);
    System.out.println(user1);
  }
}

json-lib时间有些久远，jar包只更新到2010年

org.json用起来有些繁琐

Jackson、Gson、FastJson只需一两句话就可以搞定