java中对象转json字符串的几种常用方式举例

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
// 创建一个对象
MyClass obj = new MyClass(1, "Example");
// 创建ObjectMapper实例
ObjectMapper objectMapper = new ObjectMapper();
try {
    // 将对象转换为JSON字符串
    String jsonString = objectMapper.writeValueAsString(obj);
    System.out.println(jsonString);
} catch (JsonProcessingException e) {
    e.printStackTrace();
}

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.12.5</version>
</dependency>

import com.google.gson.Gson;
// 创建一个对象
MyClass obj = new MyClass(1, "Example");
// 创建Gson实例
Gson gson = new Gson();
// 将对象转换为JSON字符串
String jsonString = gson.toJson(obj);
System.out.println(jsonString);

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.8</version>
</dependency>

//将对象（vo）转为JSONObject
       JSONObject jsonObject = (JSONObject) JSONObject.toJSON(order);
//将对象数据转为字符串               
       String jsonString = JSON.toJSONString(jsonObject);

<dependency>
			<groupId>cn.hutool</groupId>
			<artifactId>hutool-all</artifactId>
			<version>5.8.20</version>
		</dependency>

package com.hjp.test;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.hjp.DO.Person;
import org.junit.Test;
public class Json {
    @Test
    public void test02() {
        // 创建对象（嵌套两层）
        Person person = new Person("hjp", 20000, 22, "男", "area", new Person("lcr", 20000, 22, "男", "area"));
        // 将对象转为json字符串方法
        String jsonString = JSONObject.toJSONString(person);
        System.out.println("jsonString = " + jsonString);
        // 将json字符串转化为对象
        Person parseObject = JSON.parseObject(jsonString, Person.class);
        // 验证：嵌套格式的json字符串被全部转为对象格式
        String name = parseObject.getPerson().getName();
        System.out.println("name = " + name);
    }
}

import lombok.Data;
@Data
public class Person {
    private String name;  // 姓名
    private int salary; // 薪资
    private int age; // 年龄
    private String sex; //性别
    private String area;  // 地区
    private Person person;// 嵌套对象（Person）
    // 构造方法
    public Person() {
    }
    public Person(String name, int salary, int age, String sex, String area) {
        this.name = name;
        this.salary = salary;
        this.age = age;
        this.sex = sex;
        this.area = area;
    }
    public Person(String name, int salary, int age, String sex, String area, Person person) {
        this.name = name;
        this.salary = salary;
        this.age = age;
        this.sex = sex;
        this.area = area;
        this.person = person;
    }
}