Mybatis搭建过程

Mybatis搭建过程

1.导入jar包

添加配置文件：log4j.xml

       
       
          
<log4j:configuration xmlns:log4j='http://jakarta.apache.org/log4j/' >       
          
    <appender name="myConsole" class="org.apache.log4j.ConsoleAppender">       
        <layout class="org.apache.log4j.PatternLayout">       
            <param name="ConversionPattern"          
                value="[%d{dd HH:mm:ss,SSS\} %-5p] [%t] %c{2\} - %m%n" />       
        layout>       
               
        <filter class="org.apache.log4j.varia.LevelRangeFilter">       
            <param name="levelMin" value="debug" />       
            <param name="levelMax" value="warn" />       
            <param name="AcceptOnMatch" value="true" />       
        filter>       
    appender>       
       
    <appender name="myFile" class="org.apache.log4j.RollingFileAppender">          
        <param name="File" value="E:/output.log" />       
               
        <param name="Append" value="true" />       
        <param name="MaxBackupIndex" value="10" />       
        <layout class="org.apache.log4j.PatternLayout">       
            <param name="ConversionPattern" value="%p (%c:%L)- %m%n" />       
        layout>       
    appender>       
         
    <appender name="activexAppender" class="org.apache.log4j.DailyRollingFileAppender">       
        <param name="File" value="E:/activex.log" />         
        <param name="DatePattern" value="'.'yyyy-MM-dd'.log'" />         
        <layout class="org.apache.log4j.PatternLayout">       
         <param name="ConversionPattern"         
            value="[%d{MMdd HH:mm:ss SSS\} %-5p] [%t] %c{3\} - %m%n" />       
        layout>         
    appender>       
          
           
    <logger name="com.runway.bssp.activeXdemo" additivity="false">       
                 
        <appender-ref ref="activexAppender" />         
    logger>       
       
           
    <root>       
               
        <appender-ref ref="myConsole"/>       
        <appender-ref ref="myFile"/>          
    root>       
log4j:configuration>

2.创建Mybatis的核心配置文件（取名为Mybatis-config.xml）,添加jdbc.properties数据库连接参数配置文件

        
<configuration>

<properties resource="jdbc.properties">properties>
<settings>

<setting name="mapUnderscoreToCamelCase" value="true"/>
settings>

<typeAliases>

<typeAlias type="com.ourenlongblog.bean.User" alias="User"/>
typeAliases>

	<environments default="mysql">
		<environment id="mysql">
			<transactionManager type="JDBC">transactionManager>
			<dataSource type="POOLED">
			
				<property name="driver" value="${jdbc.driver}" />
				<property name="url" value="${jdbc.url}" />
				<property name="username" value="${jdbc.username}" />
				<property name="password" value="${jdbc.password}" />
			dataSource>
		environment>
	environments>
	<mappers>
		<mapper resource="UserMapper.xml" />
	mappers>
configuration>

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ourenlongbk?characterEncoding=UTF-8&characterSetResults=UTF-8&zeroDateTimeBehavior=convertToNull&serverTimezone=UTC
jdbc.username=root
jdbc.password=root

3.创建映射文件，并配置
例如实体类：

package com.ourenlongblog.bean;

public class User {

	private Integer id;

	private String userName;

	private String password;

	private Integer age;

	public User() {

	}

	public User(Integer id, String userName, String password, Integer age) {
		super();
		this.id = id;
		this.userName = userName;
		this.password = password;
		this.age = age;
	}

	@Override
	public String toString() {
		return "User [id=" + id + ", userName=" + userName + ", password=" + password + ", age=" + age + "]";
	}
}

映射配置文件UserMapper.xml：

<mapper namespace="com.ourenlongblog.Mapper.UserMapper">
 <select id="getUserById" resultType="com.ourenlongblog.bean.User" >
 select * from user where id = #{id}
 select>
mapper>

4.创建Mapper接口，实现两个绑定
（1）创建UserMapper接口

package com.ourenlongblog.Mapper;

import com.ourenlongblog.bean.User;

public interface UserMapper {
	
	User getUserById(String id);

}

（2）绑定UserMapper.xml中的：

<mapper namespace="com.ourenlongblog.Mapper.UserMapper">

(3) 绑定id=接口中的方法名,resultType=SQL语句执行后返回的数据类型

<select id="getUserById" resultType="com.ourenlongblog.bean.User" >

5.获取Mybatis操作数据会话对象SqlSession

InputStream is=Resources.getResourceAsStream("mybatis-config.xml");
		
SqlSessionFactory sessionFactory  = new SqlSessionFactoryBuilder().build(is);

SqlSession sqlSession = sessionFactory.openSession();
		

6.测试

package com.ourenlongblog.Mapper;



import java.io.IOException;
import java.io.InputStream;

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.jupiter.api.Test;
import com.ourenlongblog.bean.User;

class TestMybatis {

	@Test
	void test() throws IOException {
		InputStream is=Resources.getResourceAsStream("mybatis-config.xml");
		
		SqlSessionFactory sessionFactory  = new SqlSessionFactoryBuilder().build(is);
		
		SqlSession sqlSession = sessionFactory.openSession();
		
		UserMapper mapper = sqlSession.getMapper(UserMapper.class);
		
		User user = mapper.getUserById("1");
		
		System.out.println(user);
	}

}

xml的提示功能：

编写SQL语句时需要注意的问题