mybatis学习笔记(2)搭建环境

搭建环境流程如下四点：

1. 创建maven工程并导入坐标

   <dependencies>
   	
   	       <dependency>
   	           <groupId>org.mybatis</groupId>
   	           <artifactId>mybatis</artifactId>
   	           <version>3.4.5</version>
   	       </dependency>
   	       <dependency>
   	           <groupId>mysql</groupId>
   	           <artifactId>mysql-connector-java</artifactId>
   	           <version>5.1.43</version>
   	       </dependency>
   	
   	       <dependency>
   	           <groupId>log4j</groupId>
   	           <artifactId>log4j</artifactId>
   	           <version>1.2.12</version>
   	       </dependency>
   	
   	       <dependency>
   	           <groupId>junit</groupId>
   	           <artifactId>junit</artifactId>
   	           <version>4.10</version>
   	       </dependency>
   	
   </dependencies>
   

   　创建实体类和Mapper的接口

   public class User implements Serializable {
   		
   	private int id ;
   	private String username;
   	......
   }
   

   　　

   public interface IUserMapper {
   	/**
   	* 查询所有操作
   	* @return
   	*/
   	List<User> findAll();
   }
   

   　　创建mybatis的主配置文件

   <configuration>
       <!--配置环境-->
       <environments default="mysql">
           <!--配置Mysql的环境-->
           <environment id="mysql">
               <!--配置事务的类型-->
               <transactionManager type="JDBC"></transactionManager>
               <!--配置数据源(连接池)-->
               <dataSource type="POOLED">
                   <!--配置连接数据库的四个基本信息-->
                   <property name="driver" value="com.mysql.jdbc.Driver" />
                   <property name="url" value="jdbc:mysql://localhost:3306/db1" />
                   <property name="username" value="root" />
                   <property name="password" value="root" />
               </dataSource>
           </environment>
       </environments>
   
       <mappers>
           <mapper resource="Mybatis/IuserMapper.xml" />
       </mappers>
   
   </configuration>
   

   　　创建映射配置文件

   <mapper namespace="com.Mapper.IUserMapper" >
       <select id="findAll" resultType="com.Pojo.User" >
           select * from usr
       </select>
   </mapper>
   

   　　测试方法

   　

   ......
   
   InputStream in = Resources.getResourceAsStream("mybatis/MapperConfig.xml");
   //创建SqlSessionFactory工厂
   SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
   SqlSessionFactory factory = builder.build(in);
   //使用工厂生产SqlSession对象
   SqlSession session = factory.openSession();
   //使用SqlSession创建Mapper接口的代理对象
   UserMapper userMapper = session.getMapper(UserMapper.class);
   //使用代理对象执行方法
   List<mybatis_user> users = userMapper.findAll();
   for (mybatis_user muser : users){
       System.out.println(muser);
   }
   session.close();
   in.close();
   
   ......