MyBatis-Plus笔记——基础环境搭建

Spring 基础环境

Spring 基础环境指的是 Spring + MyBatis + 辅助类

1.引入依赖

<properties>  
    <maven.compiler.source>22</maven.compiler.source>  
    <maven.compiler.target>22</maven.compiler.target>  
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
    <spring.version>6.1.5</spring.version>  
</properties>  
  
<dependencies>  
    <!--spring web相关-->  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-context</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  
    <!--spring 数据库相关-->  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-jdbc</artifactId>  
        <version>${spring.version}</version>  
    </dependency>  
    <!--spring test相关-->  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-test</artifactId>  
        <version>6.1.5</version>  
    </dependency>  
    <!--连接池-->  
    <dependency>  
        <groupId>com.alibaba</groupId>  
        <artifactId>druid</artifactId>  
        <version>1.2.22</version>  
    </dependency>  
    <!--MySQL驱动-->  
    <dependency>  
        <groupId>com.mysql</groupId>  
        <artifactId>mysql-connector-j</artifactId>  
        <version>8.3.0</version>  
    </dependency>  
    <!--junit测试-->  
    <dependency>  
        <groupId>junit</groupId>  
        <artifactId>junit</artifactId>  
        <version>4.13.2</version>  
        <scope>test</scope>  
    </dependency>  
    <!--日志-->  
    <dependency>  
        <groupId>org.slf4j</groupId>  
        <artifactId>slf4j-api</artifactId>  
        <version>2.0.12</version>  
    </dependency>  
    <!--更方便的日志框架，log4j升级版-->  
    <dependency>  
        <groupId>ch.qos.logback</groupId>  
        <artifactId>logback-classic</artifactId>  
        <version>1.5.3</version>  
    </dependency>  
    <!--lombok注解处理-->  
    <dependency>  
        <groupId>org.projectlombok</groupId>  
        <artifactId>lombok</artifactId>  
        <version>1.18.30</version>  
    </dependency>  
    <!--MyBatis-Plus依赖-->  
    <dependency>  
        <groupId>com.baomidou</groupId>  
        <artifactId>mybatis-plus</artifactId>  
        <version>3.5.4.1</version>  
    </dependency>  
    <!--spring整合mybatis-->  
	<dependency>  
	    <groupId>org.mybatis</groupId>  
	    <artifactId>mybatis-spring</artifactId>  
	    <version>3.0.3</version>  
	</dependency>
</dependencies>

2. 创建数据对应实体类和mapper以及映射文件

目录结构参考

对应的实体类

@Data  
@AllArgsConstructor  
public class User {  
    private Long id;  
    private String name;  
    private Integer age;  
    private String email;  
}

对应的mapper和映射文件

mapper:

public interface UserMapper {  
  
    User selectById(Long id);  
  
}

mapper.xml:

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE mapper  
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"  
        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">  
<mapper namespace="com.zxb.mp.mapper.UserMapper">  
    <select id="selectById" resultType="com.zxb.mp.pojo.User">  
        select * from user where id = #{id}  
    </select>  
</mapper>

3.创建数据库连接配置文件

jdbc.properties:
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4. 创建`MyBatis-config`核心配置文件

详细可以参考：2.MyBatis环境搭建

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE configuration  
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"  
        "https://mybatis.org/dtd/mybatis-3-config.dtd">  
<configuration>  
    <properties resource="jdbc.properties"/>  
    <typeAliases>  
        <package name="com.zxb.mp.pojo"/>  
    </typeAliases>  
    <environments default="development">  
        <environment id="development">  
            <transactionManager type="JDBC"/>  
            <dataSource type="POOLED">  
                <property name="driver" value="${jdbc.driver}"/>  
                <property name="url" value="${jdbc.url}"/>  
                <property name="username" value="${jdbc.username}"/>  
                <property name="password" value="${jdbc.password}"/>  
            </dataSource>  
        </environment>  
    </environments>  
    <mappers>  
        <package name="com.zxb.mp.mapper"/>  
    </mappers>  
</configuration>

5. 创建Spring的配置文件

resources\applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 引入jdbc.properties -->
    <context:property-placeholder location="classpath:jdbc.properties"/>
    <!-- 配置Druid数据源 -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driver}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>
    <!-- 配置用于创建SqlSessionFactory的工厂bean -->
    <bean class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 设置MyBatis配置文件的路径（可以不设置） -->
        <property name="configLocation" value="classpath:mybatis-config.xml">
        </property>
        <!-- 设置数据源 -->
        <property name="dataSource" ref="dataSource"/>
        <!-- 设置类型别名所对应的包 -->
        <property name="typeAliasesPackage" value="com.zxb.mp.pojo">
        </property>
        <!--
        设置映射文件的路径
        若映射文件所在路径和mapper接口所在路径一致，则不需要设置
        -->
        <!--
        <property name="mapperLocations" value="classpath:mapper/*.xml">
        </property>
        -->
    </bean>
    <!--
    配置mapper接口的扫描配置
    由mybatis-spring提供，可以将指定包下所有的mapper接口创建动态代理
    并将这些动态代理作为IOC容器的bean管理
    -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.zxb.mp.mapper"/>
    </bean>
</beans>

6. 添加日志功能

resources\logback.xml

<?xml version="1.0" encoding="UTF-8"?>  
<configuration debug="false">  
    <!--定义日志文件的存储地址 logs为当前项目的logs目录 还可以设置为../logs -->  
    <property name="LOG_HOME" value="logs" />  
    <!--控制台日志， 控制台输出 -->  
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">  
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">  
            <!--格式化输出：%d表示日期，%thread表示线程名，%-5level：级别从左显示5个字符  
            宽度,%msg：日志消息，%n是换行符-->            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>  
        </encoder>  
    </appender>  
    <!--myibatis log configure-->  
    <logger name="com.apache.ibatis" level="TRACE"/>  
    <logger name="java.sql.Connection" level="DEBUG"/>  
    <logger name="java.sql.Statement" level="DEBUG"/>  
    <logger name="java.sql.PreparedStatement" level="DEBUG"/>  
    <!-- 日志输出级别 -->  
    <root level="DEBUG">  
        <appender-ref ref="STDOUT" />  
    </root>  
</configuration>

测试

// 表示在Spring的环境中测试  
@RunWith(SpringJUnit4ClassRunner.class)  
// 指定Spring的配置文件  
@ContextConfiguration("classpath:applicationContext.xml")  
public class MyBatisPlusTest {  
    private static final Logger log = LoggerFactory.getLogger(MyBatisPlusTest.class);  
    // 自动注入mapper  
   @Autowired  
   private UserMapper userMapper;  
  
   @Test  
    public void testSelectById() {  
       User user = userMapper.selectById(1L);  
       log.info("user:{}", user);  
   }  
  
}

Spring 基础环境加入MyBatis-Plus

修改配置文件spring配置文件的工厂bean

将：

<!-- 配置用于创建SqlSessionFactory的工厂bean -->
<bean class="org.mybatis.spring.SqlSessionFactoryBean">
    <!-- 设置MyBatis配置文件的路径（可以不设置） -->
    <property name="configLocation" value="classpath:mybatis-config.xml">
    </property>
    <!-- 设置数据源 -->
    <property name="dataSource" ref="dataSource"/>
    <!-- 设置类型别名所对应的包 -->
    <property name="typeAliasesPackage" value="com.zxb.mp.pojo">
    </property>
    <!--
    设置映射文件的路径
    若映射文件所在路径和mapper接口所在路径一致，则不需要设置
    -->
    <!--
    <property name="mapperLocations" value="classpath:mapper/*.xml">
    </property>
    -->
</bean>

改成：

<!-- 配置用于创建SqlSessionFactory的工厂bean -->
<bean class="org.mybatis.spring.SqlSessionFactoryBean">
    <!-- 设置MyBatis配置文件的路径（可以不设置） -->
    <property name="configLocation" value="classpath:mybatis-config.xml">
    </property>
    <!-- 设置数据源 -->
    <property name="dataSource" ref="dataSource"/>
    <!-- 设置类型别名所对应的包 -->
    <property name="typeAliasesPackage" value="com.zxb.mp.pojo">
    </property>
    <!--
    设置映射文件的路径
    若映射文件所在路径和mapper接口所在路径一致，则不需要设置
    -->
    <!--
    <property name="mapperLocations" value="classpath:mapper/*.xml">
    </property>
    -->
</bean>