第一步：配置jdbc数据源或连接池

<!-- 加载配置文件 -->
<context:property-placeholder location="classpath:application.properties"/>

# application.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mvc?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
jdbc.username=root
jdbc.password=123456

<!-- 以druid为例 -->
<!-- 数据库连接池 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
    <!-- 配置连接池属性 -->
    <property name="driverClassName" value="${jdbc.driver}"/>
    <property name="url" value="${jdbc.url}"/>
    <property name="username" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
</bean>

第二步：配置SqlSessionFactory

<!-- 配置SqlSessionFactory对象 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <!-- 注入数据库连接池 -->
    <property name="dataSource" ref="dataSource"/>
    <!-- 扫描sql配置文件:mapper需要的xml文件 -->
    <property name="mapperLocations" value="classpath:mapper/*.xml"/>
</bean>

第三步：配置MapperScannerConfigurer

<!-- 配置扫描Dao接口包，动态实现Dao接口，注入到spring容器中 -->
<bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <!-- 注入sqlSessionFactory -->
    <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    <!-- 给出需要扫描Dao接口包(必须) -->
    <property name="basePackage" value="com.yzy.demo.mvc.dao"/>
</bean>

第四步：创建User实体类

package com.yzy.demo.mvc.alias;

public class User {
    private Long id;
    private String name;
    private Integer age;
    private String pwd;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
}

第五步：创建UserDao接口

package com.yzy.demo.mvc.dao;

import com.yzy.demo.mvc.alias.User;
import org.springframework.stereotype.Component;
import java.util.List;

@Component
public interface UserDao {
    List<User> getUserList();

    void addUser(User user);
}

第六步：创建user.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.yzy.demo.mvc.dao.UserDao">
    <!-- 查询list-->
    <select id="getUserList" resultType="com.yzy.demo.mvc.alias.User">
        select * from user
    </select>

    <!-- 插入user-->
    <insert id="addUser" parameterType="com.yzy.demo.mvc.alias.User">
        insert into user VALUES(id,#{name},#{age},#{pwd})
    </insert>
</mapper>

第七步：创建User Service

package com.yzy.demo.mvc.service;

import com.yzy.demo.mvc.alias.User;
import com.yzy.demo.mvc.dao.UserDao;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;

@Service
public class UserService {

    @Resource
    UserDao dao;

    public List<User> getUserList() {
        return dao.getUserList();
    }

    public void addUser(User user) {
        dao.addUser(user);
    }

第八步：创建User Controller

package com.yzy.demo.mvc.controller;

import com.yzy.demo.mvc.alias.User;
import com.yzy.demo.mvc.service.UserService;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import javax.annotation.Resource;
import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {
    @Resource
    private UserService userService;

    @RequestMapping(value = "/list", method = RequestMethod.GET)
    @ResponseBody
    public List<User> index() {
        return this.userService.getUserList();
    }

    @RequestMapping(value = "/add", method = RequestMethod.GET)
    @ResponseBody
    public List<User> add() {
        User user = new User();
        user.setAge(44);
        user.setName("add");
        user.setPwd("password");
        userService.addUser(user);
        return this.userService.getUserList();
    }

启动服务

访问http://localhost:8080/user/list

[
  {
    id: 1,
    name: "张三",
    age: 25,
    pwd: "123456"
  },
  {
    id: 2,
    name: "李四",
    age: 22,
    pwd: "666666"
  }
]

访问http://localhost:8080/user/add

[
  {
    id: 1,
    name: "张三",
    age: 25,
    pwd: "123456"
  },
  {
    id: 2,
    name: "李四",
    age: 22,
    pwd: "666666"
  },
  {
    id: 3,
    name: "add",
    age: 44,
    pwd: "password"
  }
]