23.回顾mybatis

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知识点】

   <dependencies>
           <dependency>
               <groupId>junit</groupId>
               <artifactId>junit</artifactId>
               <version>4.12</version>
           </dependency>
   
           <dependency>
               <groupId>mysql</groupId>
               <artifactId>mysql-connector-java</artifactId>
               <version>5.1.47</version>
           </dependency>
   
           <dependency>
               <groupId>org.mybatis</groupId>
               <artifactId>mybatis</artifactId>
               <version>3.5.2</version>
           </dependency>
   
           <dependency>
               <groupId>org.springframework</groupId>
               <artifactId>spring-webmvc</artifactId>
               <version>5.1.9.RELEASE</version>
           </dependency>
   
           <!--spring操作数据库的话还需要一个spring-jdbc-->
           <dependency>
               <groupId>org.springframework</groupId>
               <artifactId>spring-jdbc</artifactId>
               <version>5.1.9.RELEASE</version>
           </dependency>
           <dependency>
               <groupId>org.aspectj</groupId>
               <artifactId>aspectjweaver</artifactId>
               <version>1.8.13</version>
           </dependency>
           <dependency>
               <groupId>org.mybatis</groupId>
               <artifactId>mybatis-spring</artifactId>
               <version>2.0.2</version>
           </dependency>
       </dependencies>
   

2. 编写测试配置文件

3. 测试

回忆mybatis

1. 编写实体类

package com.faq.pojo;

import lombok.Data;

@Data
public class User {
    private int id;
    private String name;
    private String pwd;
}

2. 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.faq.pojo"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper class="com.faq.mapper.UserMapper"/>
    </mappers>

</configuration>

3. 编写接口

public interface UserMapper {

        public List<User> selectUser();

}

4. 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.faq.mapper.UserMapper">
    <select id="selectUser" resultType="user">
        select * from mybatis.user;
    </select>

</mapper>

5. 测试

public class MyTest {
    @Test
    public void Test() throws IOException {
        String resources ="mybatis-config.xml";
        InputStream in = Resources.getResourceAsStream(resources);
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(in);
        SqlSession sqlSession = sessionFactory.openSession(true);
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.selectUser();
        for (User user : userList) {
            System.out.println(user);
        }
    }
}