Jackson是目前比较好的json解析工具
我们使用Jackson需要导入他的jar包

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.12.1</version>
</dependency>

配置文件可以在下面的连接中找到

第一个SpringMVC程序：https://www.jianshu.com/p/e51f1238ab25
springmvc-servlet.xml:JSON乱码问题配置

    <!--Json处理乱码数据-->
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

创建实体类

package com.why.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private String name;
    private int age;
    private String sex;
}

创建controller

package com.why.controller;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.why.pojo.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class UserController {
    @RequestMapping("/j1")
    @ResponseBody //它就不会走视图解析器，而是返回一个字符串
    public String json1() throws JsonProcessingException {
        //jackson   ObjectMapper
        ObjectMapper mapper = new ObjectMapper();
        //创建一个对象
        User user = new User("lcf",2,"男");
        String s = mapper.writeValueAsString(user);
        return s;
    }
}

测试

Snipaste_2021-02-02_22-43-30.png