1,将数据库信息封装在配置文件里

新建一个数据库配置文件db.PRoperties
driver=com.MySQL.jdbc.Driverurl=jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTCusername=rootpassWord=123456
在主配置文件conf.xml中导入db.properties
<?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>	<properties resource="db.properties"/>	<environments default="development">		<environment id="development">			<transactionManager type="JDBC" />			<dataSource type="POOLED">				<property name="driver" value="${driver}" />				<property name="url" value="${url}" />				<property name="username" value="${username}" />				<property name="password" value="${password}" />			</dataSource>		</environment>	</environments>	<mappers>		<mapper resource="com/zhuyun/mybatis/userMapper.xml" />	</mappers></configuration>
2，配置实体类或者包的别名
1）实体类的别名
在主配置文件conf.xml中配置实体类的别名
	<!-- 配置实体类的别名 -->	<typeAliases>		<typeAlias type="com.zhuyun.mybatis.User" alias="_User"/>	</typeAliases>在映射文件userMapper.xml中，即可用别名_User来代替com.zhuyun.mybatis.User
	<select id="getUser" parameterType="int" resultType="_User">		select * from users where id = #{id}	</select>
2）包的别名
在主配置文件conf.xml中配置包的别名
	<!-- 配置包的别名-->	<typeAliases>		<!-- <typeAlias type="com.zhuyun.mybatis.User" alias="_User"/> -->		<package name="com.zhuyun.mybatis"/>	</typeAliases>在映射文件userMapper.xml中，即可用别名User来代替com.zhuyun.mybatis.User
<?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="com.zhuyun.mybatis.userMapper">		<insert id="addUser" parameterType="User">		insert into users(name,age) values(#{name}, #{age})	</insert>		<delete id="deleteUser" parameterType="int">		delete from users where id=#{id}	</delete>		<update id="updateUser" parameterType="User">		update users set name=#{name},age=#{age} where id=#{id}	</update>	<select id="getUser" parameterType="int" resultType="User">		select * from users where id = #{id}	</select>		<select id="getAllUsers" resultType="User">		select * from users	</select></mapper>
3,打印日志信息
1）添加jar包
log4j-1.2.16.jar
2）添加log4j.xml文件到src下
<?xml version="1.0" encoding="UTF-8" ?>  <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">    <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">      <appender name="console" class="org.apache.log4j.ConsoleAppender">          <param name="Target" value="System.out" />          <layout class="org.apache.log4j.PatternLayout">              <param name="ConversionPattern" value="[CateringLog] %d{yyyy-MM-dd HH:mm:ss,SSS} %-5p %c - %m%n" />          </layout>      </appender>        <appender class="org.apache.log4j.RollingFileAppender" name="file">          <param name="File" value="d:/companyProject/logs/catering.log" />          <param name="Append" value="true" />          <param name="MaxFileSize" value="1024KB" />          <param name="MaxBackupIndex" value="5" />          <layout class="org.apache.log4j.PatternLayout">              <param name="ConversionPattern" value="[CateringLog] %d{yyyy-MM-dd HH:mm:ss,SSS} %-5p %c - %m%n" />          </layout>      </appender>            <root>          <priority value="debug" />          <appender-ref ref="console" />          <appender-ref ref="file" />      </root>                  <!--通过<logger></logger>的定义可以将各个包中的类日志输出到不同的日志文件中-->      <logger name="org.springframework">          <level value="ERROR" />      </logger>            <logger name="org.mybatis.spring">          <level value="ERROR" />      </logger>            <logger name="net.sf.ehcache">          <level value="ERROR" />      </logger>            <logger name="com.mchange.v2">          <level value="ERROR" />      </logger>            <logger name="java.sql">          <level value="debug" />      </logger>              </log4j:configuration>
3）正常运行即可出现日志信息