使用MyBatis框架连接MySQL数据库查询记录，全部步骤

系统：Windows 10 ×64
使用软件：eclipse IDE、Navicat Premiun 12、MySQL 5.7

1.在Eclipse IDE中创建Java project

2.配置JAVA 环境（增加三个外部jar包）


3.创建类包、类、xml配置文件

4.编写代码
Client.java(客户端，运行此类查询数据库student表中所有信息)

package client;
import java.io.*;
import java.util.List;
import org.apache.ibatis.io.*;
import org.apache.ibatis.session.*;
import domain.User;
public class Client {
	public static void main(String args[]) throws IOException {
		InputStream in=Resources.getResourceAsStream("mybatis-config.xml");
		SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(in);
		SqlSession sqlSession=factory.openSession();
		List<User> users=sqlSession.selectList("findAllUser");
		for(User user:users)
			System.out.println(user.getUsername()+"  "+user.getPassword());
	}
}

User.java(student表记录类型的类)

package domain;
public class User {
	private String username;
	private int password;
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public int getPassword() {
		return password;
	}
	public void setPassword(int password) {
		this.password = password;
	}
}

UserMapper.xml（映射器，存放sql语句，表名：student，可根据自己表名更改）

<?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="/">
	<select id="findAllUser" resultType="domain.User">
		select * from student
	</select>
</mapper>

jdbc.properties（连接数据库配置，此文件数据库名：experiment，用户名：root，用户密码：SQL123，具体参数根据自己实际参数配置）

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/experiment?useUnicode=true&characterEncoding=utf8&useSSL=false
jdbc.username=root
jdbc.password=SQL123

log4j.properties（生成日志文件）

# Global logging configuration
log4j.rootLogger=DEBUG,Console
# MyBatis logging configuration...
log4j.logger.org.apache=DEBUG
# Console output...
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=[UMS]%2p [%t] - %m%n

mybatis-config.xml（mybatis核心配置文件）

<?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>
	<properties resource="jdbc.properties"></properties>
	<environments default="en">
		<environment id="en">
			<transactionManager type="JDBC" />
			<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="mapper/UserMapper.xml"></mapper>
	</mappers>	
</configuration>

此处分别是数据库名：experiment
用户名：root
用户密码：SQL123
根据自己实际更改配置即可

5.创建表并插入记录（数据库名：experiment，表名：student）


6.在Client.java运行，查询student表中所有记录