Spring MVC 搭配 MyBatis 框架实例详解

本文将针对如何使用 Spring MVC 框架搭配 MyBatis 框架展开讲解，包括环境搭建、配置，以及搭建一个简单的增删改查示例。

环境搭建

为了使用 Spring MVC 搭配 MyBatis 框架，我们需要先完成以下环境的搭建：

JDK：需要 JDK 版本为 1.8 或以上；
Maven：使用 Maven 进行项目依赖和管理；
Spring MVC：使用 Spring MVC 作为 Web 框架，版本为 5.3.5；
MyBatis：使用 MyBatis 作为 ORM 框架，版本为 3.5.6；
MySQL：使用 MySQL 作为数据库，版本为 8.0.23。

配置文件

pom.xml

在 Maven 的 pom.xml 文件中加入以下依赖：

<!-- Spring MVC -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.3.5</version>
</dependency>

<!-- MyBatis -->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.6</version>
</dependency>

<!-- MySQL Connector -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.23</version>
</dependency>

applicationContext.xml

在 Spring MVC 的 applicationContext.xml 文件中加入以下配置：

<!-- 数据库连接配置 -->
<bean id="dataSource" 
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.cj.jdbc.Driver" />
    <property name="url" value="jdbc:mysql://localhost:3306/mybatis_demo?useUnicode=true&amp;characterEncoding=utf8&amp;serverTimezone=UTC" />
    <property name="username" value="root" />
    <property name="password" value="123456" />
</bean>

<!-- MyBatis 配置，包括数据库连接和 mapper 配置 -->
<bean id="sqlSessionFactory" 
    class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="configLocation" value="classpath:mybatis-config.xml" />
    <property name="mapperLocations" value="classpath*:com/example/mapper/*.xml" />
</bean>

<!-- MyBatis Mapper 自动扫描 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.example.mapper" />
</bean>

<!-- 注册 Controller 类 -->
<context:component-scan base-package="com.example.controller" />

mybatis-config.xml

在 MyBatis 的 mybatis-config.xml 文件中加入以下配置：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-config.dtd" >
<configuration>
    <!-- 使用注解方式进行 Mapper 映射 -->
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true" />
        <setting name="logImpl" value="LOG4J2"/>
    </settings>

    <!-- Mapper 文件自动扫描 -->
    <mappers>
        <mapper class="com.example.mapper.UserMapper" />
    </mappers>
</configuration>

示例说明

以下是一个简单的示例，实现增删改查功能：

UserMapper.java

package com.example.mapper;

import java.util.List;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import com.example.dto.User;

public interface UserMapper {
    @Select("SELECT * FROM user")
    List<User> getUsers();

    @Select("SELECT * FROM user WHERE id = #{id}")
    User getUserById(int id);

    @Insert("INSERT INTO user (name, age) VALUES (#{name}, #{age})")
    void addUser(User user);

    @Update("UPDATE user SET name=#{name}, age=#{age} WHERE id=#{id}")
    void updateUser(User user);

    @Delete("DELETE FROM user WHERE id = #{id}")
    void deleteUser(int id);
}

UserController.java

package com.example.controller;

import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import com.example.dto.User;
import com.example.mapper.UserMapper;

@Controller
public class UserController {
    @Autowired
    private UserMapper userMapper;

    @GetMapping("/user/all")
    public String getUsers(ModelMap modelMap) {
        List<User> users = userMapper.getUsers();
        modelMap.addAttribute("users", users);
        return "user_list";
    }

    @GetMapping("/user/add")
    public String addUserView() {
        return "user_add";
    }

    @PostMapping("/user/add")
    public String addUser(User user) {
        userMapper.addUser(user);
        return "redirect:/user/all";
    }

    @GetMapping("/user/edit/{id}")
    public String editUserView(@PathVariable("id") int id, ModelMap modelMap) {
        User user = userMapper.getUserById(id);
        modelMap.addAttribute("user", user);
        return "user_edit";
    }

    @PostMapping("/user/edit")
    public String editUser(User user) {
        userMapper.updateUser(user);
        return "redirect:/user/all";
    }

    @GetMapping("/user/delete/{id}")
    public String deleteUser(@PathVariable("id") int id) {
        userMapper.deleteUser(id);
        return "redirect:/user/all";
    }
}

user_list.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <title>User List</title>
</head>
<body>
    <h1>User List</h1>
    <a href="${pageContext.request.contextPath}/user/add">Add User</a>
    <table>
        <tr>
            <th>ID</th>
            <th>Name</th>
            <th>Age</th>
            <th>Operation</th>  
        </tr>
        <c:forEach var="user" items="${users}">
            <tr>
                <td>${user.id}</td>
                <td>${user.name}</td>
                <td>${user.age}</td>
                <td>
                    <a href="${pageContext.request.contextPath}/user/edit/${user.id}">Edit</a>
                    <a href="${pageContext.request.contextPath}/user/delete/${user.id}">Delete</a>
                </td>
            </tr>
        </c:forEach>
    </table>
</body>
</html>

user_add.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <title>Add User</title>
</head>
<body>
    <h1>Add User</h1>
    <form action="${pageContext.request.contextPath}/user/add" method="post">
        <table>
            <tr>
                <td>Name:</td>
                <td><input type="text" name="name" /></td>
            </tr>
            <tr>
                <td>Age:</td>
                <td><input type="text" name="age" /></td>
            </tr>
            <tr>
                <td colspan="2"><input type="submit" value="Add" /></td>
            </tr>
        </table>
    </form>
</body>
</html>

user_edit.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <title>Edit User</title>
</head>
<body>
    <h1>Edit User</h1>
    <form action="${pageContext.request.contextPath}/user/edit" method="post">
        <table>
            <input type="hidden" name="id" value="${user.id}" />
            <tr>
                <td>Name:</td>
                <td><input type="text" name="name" value="${user.name}" /></td>
            </tr>
            <tr>
                <td>Age:</td>
                <td><input type="text" name="age" value="${user.age}" /></td>
            </tr>
            <tr>
                <td colspan="2"><input type="submit" value="Save" /></td>
            </tr>
        </table>
    </form>
</body>
</html>