mybatis的配置

mybatis 的配置

• mybatis 配置 头部关键字为config

  <?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">
  <!-- 根标签 -->
  <configuration>
      <!-- 环境，可以配置多个，default：指定采用哪个环境 -->
      <environments default="test">
          <!-- id：唯一标识 -->
          <environment id="test">
              <!-- 事务管理器，JDBC类型的事务管理器 -->
              <transactionManager type="JDBC" />
              <!-- 数据源，池类型的数据源 -->
              <dataSource type="POOLED">
                  <property name="driver" value="com.mysql.jdbc.Driver" />
                  <property name="url" value="jdbc:mysql://127.0.0.1:3306/b1908" />
                  <property name="username" value="root" />
                  <property name="password" value="ocnt-123" />
              </dataSource>
          </environment>
      </environments>
      <mappers>
          <mapper resource="com/itheima/dao/IUserDao.xml" />
      </mappers>
  </configuration>
  

• log4j.properties 日志

  log4j.rootLogger=DEBUG,A1
  log4j.logger.org.apache=DEBUG
  log4j.appender.A1=org.apache.log4j.ConsoleAppender
  log4j.appender.A1.layout=org.apache.log4j.PatternLayout
  log4j.appender.A1.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss,SSS} [%t] [%c]-[%p] %m%n
  

• mapper 配置 头部信息为 mapper

select * from user; ```

• sqlsession 查询

package com.itheima.test;
import com.itheima.dao.IUserDao;
import com.itheima.domain.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 java.io.InputStream;
import java.util.List;

public class MyBatisTest {
public static void main(String[] args) throws Exception{
// 1 读取配置文件
InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
// 2 创建 SqlSessionFactory 工厂
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory factory = builder.build(in);
// 3 使用工厂生成 sqlsession 对象
SqlSession session = factory.openSession();
// 4 使用 sqlsession 创建 dao 接口的代理对象
IUserDao userDao = session.getMapper(IUserDao.class);
// 5 使用代理对象执行
List users = userDao.findAll();
for (User user:users) {
System.out.println(user);
}
// 6 关闭
session.close();
in.close();
}
}