SpringMVC JSON

基础环境搭建请参考SringMVC入门程序

1：JSON依赖

<dependency>
   <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.10.0</version>
</dependency>

2：编写JSON工具类

com\applesnt\util\JsonUtils.java

 package com.applesnt.util;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import java.text.SimpleDateFormat;

/*json工具类*/
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) {
        /*jackson提供的对象 ObjectMapper*/
        ObjectMapper mapper = new ObjectMapper();
        //不使用时间戳的方式
        mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        //自定义日期格式对象
        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;
    }
}

3：编写配置 解决JSON乱码问题

resources\springmvc-servlet.xml

<?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
        https://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">


    <context:component-scan base-package="com.applesnt.controller"/>

    <!-- 让Spring MVC不处理静态资源 -->
    <mvc:default-servlet-handler />

    <!--使用注解驱动，并解决jackson乱码问题-->
    <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>

    <!--视图解析器:DispatcherServlet给他的ModelAndView-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">

        <property name="prefix" value="/WEB-INF/jsp/"/>

        <property name="suffix" value=".jsp"/>
    </bean>

</beans>

4：编写controller

com\applesnt\vo\UserVo.java

 package com.applesnt.vo;

import lombok.Data;

@Data
public class UserVo {
    private String id;
    private String name;
    private String sex;

    public UserVo(String id, String name, String sex) {
        this.id = id;
        this.name = name;
        this.sex = sex;
    }
}

com\applesnt\controller\JsonController.java

package com.applesnt.controller;

import com.applesnt.util.JsonUtils;
import com.applesnt.vo.UserVo;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

@Controller
public class JsonController {

    /*对象转json*/
    @RequestMapping("/getjson1")
    @ResponseBody
    public String getJson1(){

        UserVo userVo = new UserVo("1001","张三","男");
        String json = JsonUtils.getJson(userVo);
        return json;
    }

    /*集合转json*/
    @RequestMapping("/getjson2")
    @ResponseBody
    public String getJson2(){

        List<UserVo> list = new ArrayList<UserVo>();
        UserVo userVo1 = new UserVo("1001","张三","男");
        UserVo userVo2 = new UserVo("1002","李四","男");
        UserVo userVo3 = new UserVo("1003","王五","女");
        list.add(userVo1);
        list.add(userVo2);
        list.add(userVo3);

        String json = JsonUtils.getJson(list);
        return json;
    }

    /*时间转json*/
    @RequestMapping("/getjson3")
    @ResponseBody
    public String getJson3(){
        Date date = new Date();

        String json = JsonUtils.getJson(date,"yyyy-MM-dd HH:mm:ss");
        return json;
    }
}

5：测试结果