SpringBoot分布式项目中MyBatis实战技巧：从配置到性能优化

引言

在分布式系统架构中，SpringBoot与MyBatis的组合已成为企业级开发的黄金搭档。但在实际项目中，开发者常面临多数据源管理、SQL性能优化、分布式事务等挑战。本文将从实战角度出发，分享7个关键技巧和避坑指南。

一、多数据源动态切换实战

1.1 多数据源配置

@Configuration
public class DataSourceConfig {@Bean(name = "masterDataSource")@ConfigurationProperties(prefix = "spring.datasource.master")public DataSource masterDataSource() {return DataSourceBuilder.create().build();}@Bean(name = "slaveDataSource")@ConfigurationProperties(prefix = "spring.datasource.slave")public DataSource slaveDataSource() {return DataSourceBuilder.create().build();}
}

1.2 动态数据源路由

public class DynamicDataSource extends AbstractRoutingDataSource {@Overrideprotected Object determineCurrentLookupKey() {return DataSourceContextHolder.getDataSourceType();}
}// 使用AOP实现自动切换
@Around("execution(* com.example.service..*.*(..))")
public Object around(ProceedingJoinPoint point) {MethodSignature signature = (MethodSignature) point.getSignature();DataSourceSwitch dataSource = signature.getMethod().getAnnotation(DataSourceSwitch.class);if(dataSource != null){DataSourceContextHolder.setDataSourceType(dataSource.value());}// 执行方法...
}

注意点：

事务管理需使用@Transactional(transactionManager = "txManager")
连接池推荐使用HikariCP
读写分离场景建议结合AbstractRoutingDataSource+注解方式

二、MyBatis进阶使用技巧

2.1 动态SQL最佳实践

<select id="searchUsers" resultType="User">SELECT * FROM users<where><if test="name != null">AND name LIKE CONCAT('%',#{name},'%')</if><if test="status != null">AND status = #{status}</if><choose><when test="orderBy == 'name'">ORDER BY name</when><otherwise>ORDER BY create_time DESC</otherwise></choose></where>
</select>

2.2 自定义TypeHandler

处理枚举类型和加密字段：

public class EncryptTypeHandler extends BaseTypeHandler<String> {private final Encryptor encryptor = new AESEncryptor();@Overridepublic void setNonNullParameter(PreparedStatement ps, int i, String parameter, JdbcType jdbcType) {ps.setString(i, encryptor.encrypt(parameter));}// 其他方法实现解密...
}// 实体类使用
public class User {@TableField(typeHandler = EncryptTypeHandler.class)private String mobile;
}

三、性能优化三板斧

3.1 批量插入优化

public void batchInsert(List<User> users) {SqlSession sqlSession = sqlSessionTemplate.getSqlSessionFactory().openSession(ExecutorType.BATCH);try {UserMapper mapper = sqlSession.getMapper(UserMapper.class);for (User user : users) {mapper.insert(user);}sqlSession.commit();} finally {sqlSession.close();}
}

3.2 二级缓存配置

<settings><setting name="cacheEnabled" value="true"/>
</settings><!-- Mapper级别开启 -->
<cache type="org.mybatis.caches.ehcache.EhcacheCache"/>

缓存策略建议：

读多写少的数据适合开启缓存
分布式环境建议集成Redis
及时清理关联表的缓存数据

四、分布式项目中的特殊处理

4.1 分页查询优化

// 使用PageHelper实现物理分页
PageHelper.startPage(1, 10, "id DESC");
List<User> users = userMapper.selectByCondition(condition);
PageInfo<User> pageInfo = new PageInfo<>(users);// 深度分页优化（基于游标）
@Select("SELECT * FROM users WHERE id > #{lastId} ORDER BY id LIMIT #{size}")
List<User> selectByScroll(@Param("lastId") Long lastId, @Param("size") int size);

4.2 SQL拦截器开发

公共字段自动填充插件示例：

@Intercepts({@Signature(type = Executor.class, method = "update", args = {MappedStatement.class, Object.class})
})
public class AutoFillInterceptor implements Interceptor {@Overridepublic Object intercept(Invocation invocation) throws Throwable {Object parameter = invocation.getArgs()[1];if(parameter instanceof BaseEntity){BaseEntity entity = (BaseEntity) parameter;entity.setUpdateTime(new Date());entity.setUpdater(getCurrentUser());}return invocation.proceed();}
}

五、避坑指南

5.1 警惕N+1查询问题

<!-- 错误示范 -->
<resultMap id="userMap" type="User"><collection property="orders" select="selectOrdersByUserId" column="id"/>
</resultMap><!-- 正确方案：使用JOIN查询 -->
<select id="selectUserWithOrders" resultMap="userOrderMap">SELECT u.*, o.* FROM users uLEFT JOIN orders o ON u.id = o.user_id
</select>