Spring Boot集成MyBatis与MySQL开发全攻略

一、前言：现代Java持久层开发的选择

在微服务架构盛行的今天，Spring Boot以其"约定优于配置"的理念成为Java开发的事实标准。结合MyBatis这一灵活高效的ORM框架和MySQL这一成熟稳定的关系型数据库，构成了企业级应用开发的黄金三角组合。本文将深入探讨三者的整合之道，通过实战案例揭示其核心技术要点。

二、核心技术解析

2.1 Spring Boot的自动配置魔法

• 启动原理：通过@SpringBootApplication注解触发自动配置
• 依赖管理：starter机制简化依赖版本管理
• 嵌入式容器：默认集成Tomcat/Jetty等Web容器

2.2 MyBatis的核心竞争力

• SQL可见性：完整掌控SQL语句编写
• 动态SQL：支持if/choose/when等条件语句
• 插件扩展：支持分页、性能分析等插件

// 动态SQL示例
public interface UserMapper {
    @SelectProvider(type = UserSqlBuilder.class, method = "buildGetUsersByCriteria")
    List<User> getByCriteria(UserCriteria criteria);
    
    class UserSqlBuilder {
        public String buildGetUsersByCriteria(UserCriteria criteria) {
            return new SQL(){{
                SELECT("*");
                FROM("users");
                if (criteria.getUsername() != null) {
                    WHERE("username = #{username}");
                }
                if (criteria.getEmail() != null) {
                    WHERE("email LIKE CONCAT(#{email}, '%')");
                }
                ORDER_BY("create_time DESC");
            }}.toString();
        }
    }
}

2.3 MySQL的工程实践优势

• 事务支持：完整ACID特性实现
• 存储引擎：InnoDB与MyISAM的选型策略
• 性能优化：索引策略与查询优化器

三、系统集成架构

3.1 分层架构设计

┌─────────────┐
│   Client    │
└──────┬──────┘
       │
┌──────▼──────┐
│ Controller  │
└──────┬──────┘
       │
┌──────▼──────┐
│   Service   │
└──────┬──────┘
       │
┌──────▼──────┐
│   Mapper    │
└──────┬──────┘
       │
┌──────▼──────┐
│   MySQL     │
└─────────────┘

3.2 数据流向示意图

四、详细实现步骤

4.1 项目初始化（IntelliJ IDEA版）

1. 创建Spring Boot项目（2.7.x+）
2. 选择依赖：Web、MyBatis、MySQL Driver
3. 配置pom.xml验证依赖项

<!-- 关键依赖示例 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>3.0.3</version>
</dependency>
<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <scope>runtime</scope>
</dependency>

4.2 数据库配置进阶

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/app_db?characterEncoding=UTF-8&useSSL=false&allowPublicKeyRetrieval=true
    username: app_user
    password: s3cr3tP@ss
    hikari:
      connection-timeout: 3000
      maximum-pool-size: 20

mybatis:
  configuration:
    default-fetch-size: 100
    default-statement-timeout: 30
    map-underscore-to-camel-case: true
  type-aliases-package: com.example.domain

4.3 领域模型设计

@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class User {
    private Long id;
    private String username;
    private String encryptedPassword;
    private String email;
    private UserStatus status;
    private LocalDateTime createTime;
    private LocalDateTime updateTime;
}

public enum UserStatus {
    ACTIVE, INACTIVE, LOCKED
}

4.4 数据访问层实现

注解方式

@Mapper
public interface UserMapper {
    @Select("SELECT * FROM users WHERE id = #{id}")
    @Results({
        @Result(property = "createTime", column = "create_time"),
        @Result(property = "updateTime", column = "update_time")
    })
    User selectById(Long id);
}

XML映射方式

<!-- resources/mapper/UserMapper.xml -->
<mapper namespace="com.example.mapper.UserMapper">
    <resultMap id="userResultMap" type="User">
        <id property="id" column="id"/>
        <result property="username" column="username"/>
        <result property="encryptedPassword" column="encrypted_password"/>
        <result property="email" column="email"/>
        <result property="status" column="status" 
                typeHandler="org.apache.ibatis.type.EnumTypeHandler"/>
        <result property="createTime" column="create_time"/>
        <result property="updateTime" column="update_time"/>
    </resultMap>

    <select id="selectAll" resultMap="userResultMap">
        SELECT * FROM users
    </select>
</mapper>

4.5 事务管理实践

@Service
@RequiredArgsConstructor
public class UserRegistrationService {
    private final UserMapper userMapper;
    private final AuditLogMapper auditLogMapper;

    @Transactional(rollbackFor = Exception.class)
    public void registerUser(User user) {
        userMapper.insert(user);
        auditLogMapper.logEvent("USER_REGISTER", user.getId());
        // 其他业务操作...
    }
}

五、高级特性应用

5.1 MyBatis插件开发

实现SQL执行时间监控：

@Intercepts({
    @Signature(type = Executor.class, method = "update", args = {MappedStatement.class, Object.class}),
    @Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class})
})
public class SqlCostInterceptor implements Interceptor {
    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        long start = System.currentTimeMillis();
        try {
            return invocation.proceed();
        } finally {
            long cost = System.currentTimeMillis() - start;
            System.out.println("SQL执行耗时：" + cost + "ms");
        }
    }
}

5.2 多数据源配置

@Configuration
@MapperScan(basePackages = "com.example.primary.mapper", 
           sqlSessionFactoryRef = "primarySqlSessionFactory")
public class PrimaryDataSourceConfig {
    
    @Bean
    @ConfigurationProperties("spring.datasource.primary")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    public SqlSessionFactory primarySqlSessionFactory(
            @Qualifier("primaryDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
        factory.setDataSource(dataSource);
        factory.setMapperLocations(
            new PathMatchingResourcePatternResolver()
                .getResources("classpath:mapper/primary/*.xml"));
        return factory.getObject();
    }
}

六、性能优化策略

6.1 查询优化方案

优化手段	实施方法	预期效果
二级缓存	配置标签	减少数据库访问
批量插入	使用foreach标签	提升写入性能
延迟加载	配置lazyLoadingEnabled=true	减少内存消耗
分页插件	集成PageHelper	简化分页操作

6.2 索引优化示例

-- 创建复合索引
CREATE INDEX idx_users_username_email ON users(username, email);

-- 执行计划分析
EXPLAIN SELECT * FROM users WHERE username = 'john' AND email LIKE '%@example.com';

七、测试验证方案

7.1 单元测试示例

@SpringBootTest
class UserMapperTest {
    
    @Autowired
    private UserMapper userMapper;

    @Test
    @Sql(scripts = "/test-data.sql")
    void testSelectById() {
        User user = userMapper.selectById(1L);
        assertThat(user.getUsername()).isEqualTo("testuser");
    }
}

7.2 API测试脚本

# 创建测试用户
curl -X POST -H "Content-Type: application/json" \
-d '{"username":"devuser","email":"dev@example.com"}' \
http://localhost:8080/api/users

# 查询用户信息
curl -X GET http://localhost:8080/api/users/1

八、生产环境建议

8.1 安全配置

spring:
  datasource:
    password: ${DB_PASSWORD} # 从环境变量读取
    hikari:
      connection-init-sql: SELECT 1 FROM DUAL # 连接验证

8.2 监控配置

@Bean
public MeterRegistryCustomizer<MeterRegistry> metricsCommonTags() {
    return registry -> registry.config().commonTags(
            "application", "user-service",
            "datasource", "mysql"
    );
}

附完整项目结构：

src/main/java
├── com.example
│   ├── config       # 配置类
│   ├── controller   # Web层
│   ├── service      # 业务层
│   ├── mapper       # 数据访问层
│   └── domain       # 领域模型
resources/
├── application.yml  # 主配置文件
└── mapper/          # XML映射文件
生产级应用的优化策略

未来可探索方向：
- 结合Redis实现缓存层
- 集成MyBatis-Plus增强功能
- 实现多租户数据隔离
- 探索分布式事务解决方案

附完整项目结构：

src/main/java
├── com.example
│ ├── config # 配置类
│ ├── controller # Web层
│ ├── service # 业务层
│ ├── mapper # 数据访问层
│ └── domain # 领域模型
resources/
├── application.yml # 主配置文件
└── mapper/ # XML映射文件