mybatis学习笔记(2)搭建环境()-MyBatis

发表于： 3月 18, 2023 3月 18, 2023
分类：建站
标签： mybatis

mybatis学习笔记(2)搭建环境()

搭建环境流程如下四点：

创建maven工程并导入坐标

org.mybatis
mybatis
3.4.5

mysql
mysql-connector-java
5.1.43

log4j
log4j
1.2.12

junit
junit
4.10

　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 findAll();
}

　　创建mybatis的主配置文件

　　创建映射配置文件

　　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 users = userMapper.findAll();
for (mybatis_user muser : users){
System.out.println(muser);
}
session.close();
in.close();

……

<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>

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

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

<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>

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

......

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();

......

————————

搭建环境流程如下四点：

创建maven工程并导入坐标

org.mybatis
mybatis
3.4.5

mysql
mysql-connector-java
5.1.43

log4j
log4j
1.2.12

junit
junit
4.10

　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 findAll();
}

　　创建mybatis的主配置文件

　　创建映射配置文件

　　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 users = userMapper.findAll();
for (mybatis_user muser : users){
System.out.println(muser);
}
session.close();
in.close();

……

<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>

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

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

<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>

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

......

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();

......