<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
   <groupId>com.fasterxml.jackson.core</groupId>
   <artifactId>jackson-databind</artifactId>
   <version>2.9.8</version>
</dependency>

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
        version="4.0">

   <!--1.注冊(cè)servlet-->
   <servlet>
       <servlet-name>SpringMVC</servlet-name>
       <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
       <!--通過(guò)初始化參數(shù)指定SpringMVC配置文件的位置，進(jìn)行關(guān)聯(lián)-->
       <init-param>
           <param-name>contextConfigLocation</param-name>
           <param-value>classpath:springmvc-servlet.xml</param-value>
       </init-param>
       <!-- 啟動(dòng)順序，數(shù)字越小，啟動(dòng)越早 -->
       <load-on-startup>1</load-on-startup>
   </servlet>

   <!--所有請(qǐng)求都會(huì)被springmvc攔截 -->
   <servlet-mapping>
       <servlet-name>SpringMVC</servlet-name>
       <url-pattern>/</url-pattern>
   </servlet-mapping>

   <filter>
       <filter-name>encoding</filter-name>
       <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
       <init-param>
           <param-name>encoding</param-name>
           <param-value>utf-8</param-value>
       </init-param>
   </filter>
   <filter-mapping>
       <filter-name>encoding</filter-name>
       <url-pattern>/</url-pattern>
   </filter-mapping>

</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns:context="http://www.springframework.org/schema/context"
      xmlns:mvc="http://www.springframework.org/schema/mvc"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/mvc
       https://www.springframework.org/schema/mvc/spring-mvc.xsd">

   <!-- 自動(dòng)掃描指定的包，下面所有注解類交給IOC容器管理 -->
   <context:component-scan base-package="com.kuang.controller"/>

   <!-- 視圖解析器 -->
   <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
         id="internalResourceViewResolver">
       <!-- 前綴 -->
       <property name="prefix" value="/WEB-INF/jsp/" />
       <!-- 后綴 -->
       <property name="suffix" value=".jsp" />
   </bean>

</beans>

package com.kuang.pojo;

public class User {
    private String name;
    private int age;
    private String sex;

    /**省略setter和getter方法*/

//produces:指定響應(yīng)體返回類型和編碼
@RequestMapping(value = "/json1",produces = "application/json;charset=utf-8")

<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>

@RestController
public class UserController {

    //produces:指定響應(yīng)體返回類型和編碼
    @RequestMapping(value = "/json1")
    public String json1() throws JsonProcessingException {
        //創(chuàng)建一個(gè)jackson的對(duì)象映射器，用來(lái)解析數(shù)據(jù)
        ObjectMapper mapper = new ObjectMapper();
        //創(chuàng)建一個(gè)對(duì)象
        User user = new User("秦疆1號(hào)", 3, "男");
        //將我們的對(duì)象解析成為json格式
        String str = mapper.writeValueAsString(user);
        //由于@ResponseBody注解，這里會(huì)將str轉(zhuǎn)成json格式返回；十分方便
        return str;
    }

    @RequestMapping("/json2")
    public String json2() throws JsonProcessingException {

        //創(chuàng)建一個(gè)jackson的對(duì)象映射器，用來(lái)解析數(shù)據(jù)
        ObjectMapper mapper = new ObjectMapper();
        //創(chuàng)建一個(gè)對(duì)象
        User user1 = new User("秦疆1號(hào)", 3, "男");
        User user2 = new User("秦疆2號(hào)", 3, "男");
        User user3 = new User("秦疆3號(hào)", 3, "男");
        User user4 = new User("秦疆4號(hào)", 3, "男");
        List<User> list = new ArrayList<User>();
        list.add(user1);
        list.add(user2);
        list.add(user3);
        list.add(user4);

        //將我們的對(duì)象解析成為json格式
        String str = mapper.writeValueAsString(list);
        return str;
    }

}

package com.kuang.utils;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

import java.text.SimpleDateFormat;

public class JsonUtils {
   
   public static String getJson(Object object) {
       return getJson(object,"yyyy-MM-dd HH:mm:ss");
  }

   public static String getJson(Object object,String dateFormat) {
       ObjectMapper mapper = new ObjectMapper();
       //不使用時(shí)間差的方式
       mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
       //自定義日期格式對(duì)象
       SimpleDateFormat sdf = new SimpleDateFormat(dateFormat);
       //指定日期格式
       mapper.setDateFormat(sdf);
       try {
           return mapper.writeValueAsString(object);
      } catch (JsonProcessingException e) {
           e.printStackTrace();
      }
       return null;
  }
}

<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>fastjson</artifactId>
   <version>1.2.60</version>
</dependency>

package com.kuang.controller;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.kuang.pojo.User;

import java.util.ArrayList;
import java.util.List;

public class FastJsonDemo {
   public static void main(String[] args) {
       //創(chuàng)建一個(gè)對(duì)象
       User user1 = new User("秦疆1號(hào)", 3, "男");
       User user2 = new User("秦疆2號(hào)", 3, "男");
       User user3 = new User("秦疆3號(hào)", 3, "男");
       User user4 = new User("秦疆4號(hào)", 3, "男");
       List<User> list = new ArrayList<User>();
       list.add(user1);
       list.add(user2);
       list.add(user3);
       list.add(user4);

       System.out.println("*******Java對(duì)象 轉(zhuǎn) JSON字符串*******");
       String str1 = JSON.toJSONString(list);
       System.out.println("JSON.toJSONString(list)==>"+str1);
       String str2 = JSON.toJSONString(user1);
       System.out.println("JSON.toJSONString(user1)==>"+str2);

       System.out.println("\n****** JSON字符串 轉(zhuǎn) Java對(duì)象*******");
       User jp_user1=JSON.parseObject(str2,User.class);
       System.out.println("JSON.parseObject(str2,User.class)==>"+jp_user1);

       System.out.println("\n****** Java對(duì)象 轉(zhuǎn) JSON對(duì)象 ******");
       JSONObject jsonObject1 = (JSONObject) JSON.toJSON(user2);
       System.out.println("(JSONObject) JSON.toJSON(user2)==>"+jsonObject1.getString("name"));

       System.out.println("\n****** JSON對(duì)象 轉(zhuǎn) Java對(duì)象 ******");
       User to_java_user = JSON.toJavaObject(jsonObject1, User.class);
       System.out.println("JSON.toJavaObject(jsonObject1, User.class)==>"+to_java_user);
  }
}