基于Spring Boot的MyBatis整合示例：构建简单的用户管理系统

<dependencies>
    <!-- Spring Boot Starter for MyBatis -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.2.0</version>
    </dependency>

    <!-- MySQL Driver -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>

    <!-- Spring Boot Starter Web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

3. 配置数据库连接

在src/main/resources/application.properties文件中配置数据库连接信息：

# 数据库配置
spring.datasource.url=jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root

# MyBatis配置
mybatis.mapper-locations=classpath:mapper/*.xml

4. 创建实体类

在src/main/java/com/example/demo/model/User.java中创建一个实体类：

package com.example.demo.model;

public class User {
    private Long id;
    private String username;
    private String email;

    // Getters and Setters
    public Long getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

5. 创建Mapper接口

在src/main/java/com/example/demo/mapper/UserMapper.java中创建一个Mapper接口：

package com.example.demo.mapper;

import com.example.demo.model.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;

@Mapper
public interface UserMapper {
    @Select("SELECT * FROM users")
    List<User> getAllUsers();
}

6. 创建Mapper XML文件

在src/main/resources/mapper/UserMapper.xml中创建一个Mapper XML文件：

<?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.example.demo.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="com.example.demo.model.User">
        <id column="id" property="id" jdbcType="BIGINT"/>
        <result column="username" property="username" jdbcType="VARCHAR"/>
        <result column="email" property="email" jdbcType="VARCHAR"/>
    </resultMap>

    <select id="getAllUsers" resultMap="BaseResultMap">
        SELECT * FROM users
    </select>
</mapper>

7. 创建Service类

在src/main/java/com/example/demo/service/UserService.java中创建一个Service类：

package com.example.demo.service;

import com.example.demo.mapper.UserMapper;
import com.example.demo.model.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    public List<User> getAllUsers() {
        return userMapper.getAllUsers();
    }
}

8. 创建Controller类

在src/main/java/com/example/demo/controller/UserController.java中创建一个Controller类

package com.example.demo.controller;

import com.example.demo.model.User;
import com.example.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/users")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping
    public List<User> getAllUsers() {
        return userService.getAllUsers();
    }
}

9. 启动应用程序

在src/main/java/com/example/demo/DemoApplication.java中运行Spring Boot应用程序：

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}