MyBatis 是一款优秀的半自动的轻量级的持久层框架。
创建Maven项目
pom.xml 导入相关依赖
- org.mybatis -> mybatis
- mysql-connection-java -> mysql
- org.projectlombok -> lombok
- log4j -> log4j
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>MyBatis</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.5</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.20</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.12</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
</dependencies>
</project>
-
配置
mapper
读取位置 ,解决Mapper配置文件读取不到的关键
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
</resources>
</build>
resources/config.xml
通过 config.xml
进行数据库的配置和相关Mapper的导入。
- 约束
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- SQL配置 -->
<!-- 连接配置 -->
<!-- 注册Mapper -->
</configuration>
- SQL 的相关配置
<settings>
<!-- 打印SQL语句 -->
<setting name="logImpl" value="STDOUT_LOGGING" />
</settings>
- 连接配置
<environments default="mysql">
<environment id="mysql">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
<property name="url" value="jdbc:mysql://localhost:3306/JavaWeb?userSSL=false&allowPublicKeyRetrieval=true"/>
</dataSource>
</environment>
</environments>
- 注册Mapper
<mappers>
<!-- 注解形式注册 -->
<mapper class="com.kawyang.repository.IClass" />
<!-- 配置文件方式注册 -->
<mapper resource="com/kawyang/mapper/IClassesMapper.xml" />
<mapper resource="com/kawyang/mapper/IStudentMapper.xml" />
</mappers>
entity
创建实体类对象。
lombok 会通过以下注解快速