{MyBatis}操作数据库

三：完善工程目录结构

​

三：在resources目录下编写mybatis-config.xml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>

   <!-- 加载资源文件 -->

   <properties

resource="jdbc.properties">

   </properties>

   <!--全局配置 -->

   <!--日志文件-->

   <settings>

       <setting name="logImpl"

value="LOG4J"></setting>

   </settings>

   <environments

default="development">

       <environment

id="development">

           <!--使用jdbc事物管理-->

           <transactionManager

type="JDBC"></transactionManager>

           <dataSource

type="POOLED">

               <property

name="driver" value="${driver}"/>

<!--com.mysql.jdbc.Driver-->

               <property

name="url" value="${url}"/>

               <property

name="username" value="${username}"/>

               <property

name="password" value="${password}"/>

           </dataSource>

       </environment>

   </environments>

   <mappers>

       <mapper

resource="net/togogo/mapper/UserMapper.xml"/>

   </mappers>

</configuration>

四：在resources目录下编写log4j.properties文件

​

log4j.rootCategory=debug,

stdout , R

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=[QC]

%p [%t] %C.%M(%L) | %m%n

log4j.appender.R=org.apache.log4j.DailyRollingFileAppender

log4j.appender.R.File=D:/my_log.log

log4j.appender.R.layout=org.apache.log4j.PatternLayout

log4j.appender.R.layout.ConversionPattern=%d-[TS]

%p %t %c - %m%n

log4j.logger.com.ibatis=debug

log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=debug

log4j.logger.com.ibatis.common.jdbc.ScriptRunner=debug

log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=debug

log4j.logger.org.apache.ibatis.datasource.pooled=debug

log4j.logger.org.apache.ibatis.logging=debug

log4j.logger.org.apache.ibatis.transaction=debug

log4j.logger.java.sql.Connection=debug

log4j.logger.java.sql.Statement=debug

log4j.logger.java.sql.PreparedStatement=debug,stdout

driver=com.mysql.jdbc.Driver

url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8&useSSL=true

username=root

password=123456

六：编写与数据库对应的实体类

七：在mapper文件下编写UserMapper.java文件与UserMapper.xml文件；

​

 package net.togogo.mapper;

 import net.togogo.bean.User;

 import java.util.List;

 public interface UserMapper {

     List<User> getAll();

 }

 <?xml

 version="1.0" encoding="UTF-8" ?>

 <!DOCTYPE

 mapper

         PUBLIC "-//mybatis.org//DTD

 Mapper 3.0//EN"       

 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

 <mapper

 namespace="net.togogo.mapper.UserMapper">

     <select id="getAll"

 resultType="net.togogo.bean.User">

         select * from t_user

     </select>

 </mapper>

八：在test/net/togogo目录下新建UserTest.java的测试类

import net.togogo.bean.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 org.junit.Before;

import org.junit.Test;

import java.io.IOException;

import java.io.InputStream;

import java.util.List;

public class UserTest {

   private SqlSessionFactory sessionFactory;

   @Before

   public void init(){

       InputStream is = null;

       try {

           is =

Resources.getResourceAsStream("mybatis-config.xml");

           sessionFactory = new

SqlSessionFactoryBuilder().build(is);

       } catch (IOException e) {

           e.printStackTrace();

       }

   }

   @Test

   public void GetSession(){

       SqlSession session =

sessionFactory.openSession();

       System.out.println("获取到的session是："+

session);

   }

   @Test

   public void getAll(){

       SqlSession session =

sessionFactory.openSession();

       List<User> users =

session.selectList("net.togogo.mapper.UserMapper.getAll");

users.stream().forEach(System.out::println);

       session.close();

   }

}