<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xmlns="http://xmlns.jcp.org/xml/ns/javaee"

    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"

    id="WebApp_ID" version="3.1">

    <display-name>SpringProject</display-name>

    <welcome-file-list>

        <welcome-file>index.html</welcome-file>

        <welcome-file>index.htm</welcome-file>

        <welcome-file>index.jsp</welcome-file>

        <welcome-file>default.html</welcome-file>

        <welcome-file>default.htm</welcome-file>

        <welcome-file>default.jsp</welcome-file>

    </welcome-file-list>

    <servlet>

        <servlet-name>dispatcherServlet</servlet-name>

        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <!-- 配置Spring MVC配置文件的位置和名称 -->

        <init-param>

            <param-name>contextConfigLocation</param-name>

            <param-value>classpath:springmvc.xml</param-value>

        </init-param>

        <!-- 表示容器在启动时立即加载dispatcherServlet -->

        <load-on-startup>1</load-on-startup>

    </servlet>

    <!-- 让Spring MVC控制器拦截前端所有请求 -->

    <servlet-mapping>

        <servlet-name>dispatcherServlet</servlet-name>

        <url-pattern>/</url-pattern>

    </servlet-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:aop="http://www.springframework.org/schema/aop"

    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-4.3.xsd

       http://www.springframework.org/schema/context

       http://www.springframework.org/schema/context/spring-context-4.3.xsd

       http://www.springframework.org/schema/mvc

       http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd">

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

    <!-- 解决访问html资源404，非常重要  -->

    <mvc:default-servlet-handler/>

    <mvc:annotation-driven>

    </mvc:annotation-driven>

    <bean name="/hello2" class="com.springmvc.controller.HelloController2"></bean>

</beans>

package com.springmvc.controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.ResponseBody;import com.alibaba.fastjson.JSON;import java.util.HashMap;

import java.util.Map;

import org.springframework.stereotype.Controller;

@Controller

public class HelloController {

    @RequestMapping(value="/hello",produces = "application/json; charset=utf-8")

    @ResponseBody

    public String hello() {

        // TODO Auto-generated method stub

        Map<String, String> map = new HashMap<String, String>();

        map.put("key1", "键值1");

        System.out.println(JSON.toJSONString(map));

        return JSON.toJSONString(map);

    }

}