mybatis学习10.4

菜鸟自学mybatis

1.目录结构

 

 

 

 2.pom.xml导入maven坐标

<dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.0</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.39</version>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.12</version>
    </dependency>

3.创建mybatis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">
<configuration>
    <!-- 配置 mybatis 的环境 -->
    <environments default="mysql">
        <!-- 配置 mysql 的环境 -->
        <environment id="mysql">
            <!-- 配置事务的类型 -->
            <transactionManager type="JDBC"></transactionManager>
            <!-- 配置连接数据库的信息：用的是数据源(连接池) -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <!--?useUnicode=true&amp;characterEncoding=utf-8&amp;useSSL=false
                   表示高版本mysql关闭SSL的，并设置文本格式为UTF-8 &amp；表示转移字符为&
                -->
                <property name="url" value="jdbc:mysql:///xxxx?useUnicode=true&amp;characterEncoding=utf-8&amp;useSSL=false"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <!-- 告知 mybatis 映射配置的位置 -->
    <mappers>
        <!--mapper class属性为启动mybatis的注解；resourc表示为启动配置文件-->
        <mapper class="cn.xxxx.dao.IUserDao" />
    </mappers>
</configuration>

4.创建dao接口IUserDao

public interface IUserDao {
//使用注解查询login表中的数据并封装到User实体类中并存储到List集合当中
   @Select("select * from login")
   List<User> findAll();
}

5.创建main运行类，实现查询功能

   public class MybatisTest {
    public static void main(String[] args) throws Exception {
        //加载配置文件
      InputStream in= Resources.getResourceAsStream("SqlMapConfig.xml");
        //构建SqlSessionFactory对象
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        //通过构建的读取配置文件
        SqlSessionFactory factory=builder.build(in);
        SqlSession session=factory.openSession();
　　　　　//得到mapper配置实现细节方法
        IUserDao userDao = session.getMapper(IUserDao.class);
        List<User> users=userDao.findAll();
        for (User user:users){
            System.out.printf("user"+user);
        }
        session.close();
        in.close();
    }
}

 

 具体实现细节需进行源码解读