十二、整合Mybatis
步骤：
1.导入相关jar包
- junit
- mybatis
- mysql数据库
- spring相关的
- aop织入
- mybatis-spring【new】
<dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.26</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.7</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.3.11</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.3.11</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.9.7</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.6</version> </dependency> </dependencies> <build> <resources> <resource> <directory>src/main/resources</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>true</filtering> </resource> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> </resource> </resources> </build>
2.编写配置文件
3.测试
1. 回忆mybatis
- 编写实体类
package com.hxl.pojo; import lombok.Data; @Data public class User { private int id; private String name; private String pwd; }
- 编写核心配置文件
<?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"> <!--核心配置文件--> <configuration> <typeAliases> <package name="com.hxl.pojo"/> </typeAliases> <environments default="development"> <environment id="development"> <!--事务管理--> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&useUnicode=true&characterEncoding=UTF-8"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <!--每一个Mapper.xml都需要在Mybatis核心配置文件中注册--> <mappers> <!--用class的话需要mapper的两个名字相同并且在同一个包下--> <mapper resource="com/hxl/mapper/UserMapper.xml"/> </mappers> </configuration>
- 编写接口
package com.hxl.mapper; import com.hxl.pojo.User; import java.util.List; public interface UserMapper { public List<User> selectUser(); }
- 编写Mapper.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.hxl.mapper.UserMapper"> <select id="selectUser" resultType="user"> select * from user </select> </mapper>
这里namspace的值别写错了，否则会出现绑定错误
org.apache.ibatis.binding.BindingException:Typeinterfacecom.hxl.mapper.UserMapperisnotknowntotheMapperRegistry.
而且我们可以去看一些target里面的User Mapper.xml有没有来确定自己的配置
- 测试
import com.hxl.mapper.UserMapper; import com.hxl.pojo.User; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.junit.Test; import java.io.IOException; import java.io.InputStream; import java.util.List; public class MyTest { @Test public void test() throws IOException { //之前是工具类 String resources = "mybatis-config.xml"; InputStream resourceAsStream = Resources.getResourceAsStream(resources); SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream); SqlSession sqlSession = sessionFactory.openSession(true); UserMapper mapper = sqlSession.getMapper(UserMapper.class); List<User> users = mapper.selectUser(); for (User user : users) { System.out.println(user); } } }
