refactor: rename files to Chinese and organize by category

Organized 50 interview questions into 12 categories:
- 01-分布式系统 (9 files): 分布式事务, 分布式锁, 一致性哈希, CAP理论, etc.
- 02-数据库 (2 files): MySQL索引优化, MyBatis核心原理
- 03-缓存 (5 files): Redis数据结构, 缓存问题, LRU算法, etc.
- 04-消息队列 (1 file): RocketMQ/Kafka
- 05-并发编程 (4 files): 线程池, 设计模式, 限流策略, etc.
- 06-JVM (1 file): JVM和垃圾回收
- 07-系统设计 (8 files): 秒杀系统, 短链接, IM, Feed流, etc.
- 08-算法与数据结构 (4 files): B+树, 红黑树, 跳表, 时间轮
- 09-网络与安全 (3 files): TCP/IP, 加密安全, 性能优化
- 10-中间件 (4 files): Spring Boot, Nacos, Dubbo, Nginx
- 11-运维 (4 files): Kubernetes, CI/CD, Docker, 可观测性
- 12-面试技巧 (1 file): 面试技巧和职业规划

All files renamed to Chinese for better accessibility and
organized into categorized folders for easier navigation.

Generated with [Claude Code](https://claude.com/claude-code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>
This commit is contained in:
yasinshaw
2026-03-01 00:10:53 +08:00
parent fe2e6dc2f2
commit 0e46a367c4
47 changed files with 0 additions and 0 deletions

View File

@@ -0,0 +1,177 @@
# MyBatis 核心原理
## 问题
1. MyBatis 的核心组件有哪些?
2. MyBatis 的缓存机制(一级缓存、二级缓存)?
3. MyBatis 的插件原理是什么?
4. #{} 和 ${} 的区别是什么?
5. MyBatis 如何处理批量操作?
6. MyBatis 的动态 SQL 是如何实现的?
---
## 标准答案
### 1. MyBatis 核心组件
```
Configuration全局配置
SqlSession会话
Executor执行器
StatementHandler语句处理器
ParameterHandler参数处理器
ResultSetHandler结果集处理器
```
---
### 2. 缓存机制
**一级缓存SqlSession 级别)**
```java
SqlSession session = sqlSessionFactory.openSession();
User user1 = session.selectOne("selectUser", 1);
User user2 = session.selectOne("selectUser", 1); // 从缓存获取
```
**二级缓存Mapper 级别)**
```xml
<!-- 开启二级缓存 -->
<cache/>
```
```java
User user1 = session1.selectOne("selectUser", 1);
session1.close(); // 一级缓存清空,写入二级缓存
User user2 = session2.selectOne("selectUser", 1); // 从二级缓存获取
```
---
### 3. 插件原理
**拦截的四大组件**
- Executor
- StatementHandler
- ParameterHandler
- ResultSetHandler
**示例**
```java
@Intercepts({
@Signature(type = Executor.class, method = "update", args = {MappedStatement.class, Object.class})
})
public class SqlInterceptor implements Interceptor {
@Override
public Object intercept(Invocation invocation) throws Throwable {
// 前置逻辑
Object result = invocation.proceed();
// 后置逻辑
return result;
}
}
```
---
### 4. #{} vs ${}
| 特性 | #{} | ${} |
|------|-----|-----|
| **预处理** | 是PreparedStatement | 否Statement |
| **SQL 注入** | 安全 | 不安全 |
| **类型转换** | 自动 | 需手动 |
| **动态表名/列名** | 不支持 | 支持 |
**示例**
```xml
<!-- ✅ 安全 -->
SELECT * FROM users WHERE id = #{id}
<!-- ❌ SQL 注入风险 -->
SELECT * FROM users WHERE id = ${id}
<!-- ✅ 动态表名(只能用 ${}-->
SELECT * FROM ${tableName} WHERE id = #{id}
```
---
### 5. 批量操作
**方式 1SqlSession 批量**
```java
SqlSession session = sqlSessionFactory.openSession(ExecutorType.BATCH);
try {
UserMapper mapper = session.getMapper(UserMapper.class);
for (User user : users) {
mapper.insert(user);
}
session.commit();
} finally {
session.close();
}
```
**方式 2Batch Insert**
```xml
<insert id="batchInsert">
INSERT INTO users (name, email) VALUES
<foreach collection="users" item="user" separator=",">
(#{user.name}, #{user.email})
</foreach>
</insert>
```
---
### 6. 动态 SQL
**常用标签**
```xml
<select id="findUsers" resultType="User">
SELECT * FROM users
<where>
<if test="name != null">
AND name = #{name}
</if>
<if test="email != null">
AND email = #{email}
</if>
</where>
</select>
<select id="findUsersByIds" resultType="User">
SELECT * FROM users
WHERE id IN
<foreach collection="ids" item="id" open="(" separator="," close=")">
#{id}
</foreach>
</select>
```
---
### 7. 阿里 P7 加分项
**深度理解**
- 理解 MyBatis 的代理机制MapperProxy
- 理解二级缓存的并发问题
- 理解插件的责任链模式
**实战经验**
- 有处理 MyBatis 性能问题的经验
- 有自定义插件的经验
- 有 MyBatis 与 Spring 集成的经验
**架构能力**
- 能设计多数据源方案
- 能设计分库分表的 MyBatis 方案
- 能设计 MyBatis 监控体系

File diff suppressed because it is too large Load Diff