Java对象与json字符串的转换

使用Gson--谷歌

导入依赖

//Gson pom依赖
<!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.5</version>
</dependency>

示例

//创建java对象
Person person = new Person();
person.setUname("zhangsan");
person.setAge(20);
person.setSex("男");

//创建Gson对象
Gson gson = new Gson();

//java对象转化成Json格式的字符串
String jsonString = gson.toJson(Person);

//Json格式的字符串转换成java对象
Person p = gson.fromJson(jsonString,Person.class);

使用FastJson--阿里

导入依赖

//fastJson pom依赖
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.62</version>
</dependency>

示例

//创建java对象
Person person = new Person();
person.setUname("zhangsan");
person.setAge(20);
person.setSex("男");

//Java对象转化成Json格式的字符串
//用法：JSONObject.toJsonString(Java对象);
String jsonString = JSONObject.toJSONString(Person);

//Json格式的字符串转换成Java对象
//用法：JSONObject.toJavaObject(JSON字符串,Java对象.class)
Person p = JSONObject.toJavaObject(jsonString,Person.class);

//Json格式字符串转Json对象
//用法：JSONObject.parseObject(JSON字符串)
JSONObject jsonObject = JSONObject.parseObject(jsonString);

Jackson ---Spring Mvc内置解析

导入依赖

jackson核心依赖
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.10.1</version>
</dependency>

示例

//创建java对象
Person person = new Person();
person.setUname("zhangsan");
person.setAge(20);
person.setSex("男");

// 创建ObjectMapper对象。
ObjectMapper mapper = new ObjectMapper();

// Java对象转Json格式字符串
jsonString = mapper.writeValueAsString(person);

// Json格式字符串转Java对象。
Person p= mapper.readValue(jsonString, Person.class);