寒假学习25篇

### 5.1 MyBatis整合步骤
1. 导入依赖：在您的Spring Boot项目的构建文件（如pom.xml）中添加MyBatis和数据库驱动的相关依赖。例如，如果使用MySQL数据库，您需要添加MyBatis和MySQL驱动的依赖。
2. 配置数据源：在`application.properties`或`application.yml`中配置数据库连接信息，包括数据库URL、用户名、密码、mybatis的功能配置等。
3. 创建实体类：创建与数据库表对应的实体类。
4. 创建Mapper接口：创建与数据库表交互的Mapper接口。
5. 创建Mapper接口SQL实现： 可以使用mapperxml文件或者注解方式
6. 创建程序启动类
7. 注解扫描：在Spring Boot的主应用类上添加`@MapperScan`注解，用于扫描和注册Mapper接口。
8. 使用Mapper接口：在需要使用数据库操作的地方，通过依赖注入或直接实例化Mapper接口，并调用其中的方法进行数据库操作。

### 5.2 Mybatis整合实践
1. 创建项目
2. 导入依赖

```XML
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>3.0.5</version>
</parent>

<dependencies>
<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>3.0.1</version>
</dependency>

<!-- 数据库相关配置启动器 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

<!-- druid启动器的依赖 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-3-starter</artifactId>
<version>1.2.18</version>
</dependency>

<!-- 驱动类-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.28</version>
</dependency>

<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.28</version>
</dependency>

</dependencies>
```
3. 配置文件

```YAML
server:
port: 80
servlet:
context-path: /
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
druid:
url: jdbc:mysql:///day01
username: root
password: root
driver-class-name: com.mysql.cj.jdbc.Driver

mybatis:
configuration: # setting配置
auto-mapping-behavior: full
map-underscore-to-camel-case: true
log-impl: org.apache.ibatis.logging.slf4j.Slf4jImpl
type-aliases-package: com.atguigu.pojo # 配置别名
mapper-locations: classpath:/mapper/*.xml # mapperxml位置
```
4. 实体类准备

```Java
package com.atguigu.pojo;

public class User {
private String account ;
private String password ;
private Integer id ;

public String getAccount() {
return account;
}

public void setAccount(String account) {
this.account = account;
}

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}

public Integer getId() {
return id;
}

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

@Override
public String toString() {
return "User{" +
"account='" + account + '\'' +
", password='" + password + '\'' +
", id=" + id +
'}';
}
}
```
5. Mapper接口准备

```Java
public interface UserMapper {

List<User> queryAll();
}
```
6. Mapper接口实现（XML）

位置：resources/mapper/UserMapper.xml

```Java
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- namespace = 接口的全限定符 -->
<mapper namespace="com.atguigu.mapper.UserMapper">

<select id="queryAll" resultType="user">
select * from users
</select>

</mapper>
```
7. 编写三层架构代码

> 伪代码，不添加业务接口！

1. controller

```Java
@Slf4j
@Controller
@RequestMapping("/user")
public class UserController {

@Autowired
private UserService userService;

@GetMapping("/list")
@ResponseBody
public List<User> getUser(){
List<User> userList = userService.findList();
log.info("查询的user数据为:{}",userList);
return userList;
}

}
```
2. service

```Java
@Slf4j
@Service
public class UserService {

@Autowired
private UserMapper userMapper;

public List<User> findList(){
List<User> users = userMapper.queryAll();
log.info("查询全部数据:{}",users);
return users;
}
}
```
8. 启动类和接口扫描

```Java
@MapperScan("com.atguigu.mapper") //mapper接口扫描配置
@SpringBootApplication
public class MainApplication {

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

```
9. 启动测试

### 5.3 声明式事务整合配置

依赖导入:

```XML
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
```

注：SpringBoot项目会自动配置一个 DataSourceTransactionManager，所以我们只需在方法（或者类）加上 @Transactional 注解，就自动纳入 Spring 的事务管理了

```Java
@Transactional
public void update(){
User user = new User();
user.setId(1);
user.setPassword("test2");
user.setAccount("test2");
userMapper.update(user);
}
```

### 5.4 AOP整合配置

依赖导入:

```XML
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
```

直接使用aop注解即可:

```Java
@Component
@Aspect
public class LogAdvice {

@Before("execution(* com..service.*.*(..))")
public void before(JoinPoint joinPoint){
System.out.println("LogAdvice.before");
System.out.println("joinPoint = " + joinPoint);
}

}
```