mybatis-plus快速入门以及和spring整合
MyBatis-Plus（简称 MP）是一个 MyBatis 的增强工具，在 MyBatis 的基础上只做增强不做改变，为简化开发、提高效率而生。
官网： https://mybatis.plus/ 或 https://mp.baomidou.com/
对于 Mybatis 整合MP有常常有三种用法，分别是Mybatis+MP、Spring+Mybatis+MP、Spring Boot+Mybatis+MP。
创建数据库以及表：
-- 创建测试表 CREATE TABLE `tb_user` ( `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID', `user_name` varchar(20) NOT NULL COMMENT '用户名', `password` varchar(20) NOT NULL COMMENT '密码', `name` varchar(30) DEFAULT NULL COMMENT '姓名', `age` int(11) DEFAULT NULL COMMENT '年龄', `email` varchar(50) DEFAULT NULL COMMENT '邮箱', PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8; -- 插入测试数据 INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES ('1', 'zhangsan', '123456', '张三', '18', 'test1@aaa.cn'); INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES ('2', 'lisi', '123456', '李四', '20', 'test2@bbb.cn'); INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES ('3', 'wangwu', '123456', '王五', '28', 'test3@ccc.cn'); INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES ('4', 'zhaoliu', '123456', '赵六', '21', 'test4@ddd.cn'); INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES ('5', 'sunqi', '123456', '孙七', '24', 'test5@eee.cn');
创建工程引入坐标：
<dependencies> <!-- mybatis-plus插件依赖 --> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus</artifactId> <version>3.1.1</version> </dependency> <!-- MySql --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!-- 连接池 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.11</version> </dependency> <!--简化bean代码的工具包--> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> <version>1.18.4</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.6.4</version> </dependency> </dependencies>
通过纯Mybatis与Mybatis-Plus整合：实现查询User
第一步，编写SqlMapConfig.xml文件：
<?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> <typeAliases> <package name="com.fgy.domain"/> </typeAliases> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://127.0.0.1:3306/mp?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false"/> <property name="username" value="root"/> <property name="password" value="root"/> </dataSource> </environment> </environments> <mappers> <package name="com.fgy.mapper"/> </mappers> </configuration>
第二步，编写User实体对象：（这里使用lombok进行了简化bean操作）
@Data @TableName("tb_user") public class User { private Long id; private String userName; private String password; private String name; private Integer age; private String email; }
第三步，编写UserMapper接口，继承BaseMapper，将拥有了BaseMapper中的所有方法：
public interface UserMapper extends BaseMapper<User> { }
第四步，编写TestMybatis测试用例：
public class TestMybatis { @Test public void testUserList() throws Exception { InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml"); //这里使用的是MP中的MybatisSqlSessionFactoryBuilder SqlSessionFactory sqlSessionFactory = new MybatisSqlSessionFactoryBuilder().build(inputStream); SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper userMapper = sqlSession.getMapper(UserMapper.class); // 可以调用BaseMapper中定义的方法 List<User> list = userMapper.selectList(null); for (User user : list) { System.out.println(user); } } }
Spring+Mybatis+MP：
引入坐标
<properties> <spring.version>5.1.6.RELEASE</spring.version> </properties> <dependencies> <!-- mybatis-plus插件依赖 --> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus</artifactId> <version>3.1.1</version> </dependency> <!-- MySql --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!-- 连接池 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.11</version> </dependency> <!--简化bean代码的工具包--> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> <version>1.18.4</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.6.4</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> </dependencies>
编写User对象以及UserMapper接口：
@Data @TableName("tb_user") public class User { private Long id; private String userName; private String password; private String name; private Integer age; private String email; }
public interface UserMapper extends BaseMapper<User> { }
编写applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <context:property-placeholder location="classpath:*.properties"/> <!-- 定义数据源 --> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close"> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <property name="driverClassName" value="${jdbc.driver}"/> <property name="maxActive" value="10"/> <property name="minIdle" value="5"/> </bean> <!--这里使用MP提供的sqlSessionFactory，完成了Spring与MP的整合--> <bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> </bean> <!--扫描mapper接口，使用的依然是Mybatis原生的扫描器--> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.fgy.mapper"/> </bean> </beans>
编写jdbc.properties
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://127.0.0.1:3306/mp?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false jdbc.username=root jdbc.password=root
编写测试用例：
@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations = "classpath:applicationContext.xml") public class TestMybatisSpring { @Autowired private UserMapper userMapper; @Test public void testSelectList(){ List<User> users = this.userMapper.selectList(null); for (User user : users) { System.out.println(user); } } }
