mybatis——处理数据表字段名和java实体类属性名不一致情况

当数据库表字段名和java实体类属性名不一致的情况，我们需要用<resultMap>标签处理

项目结构，数据库表字段，java实体类属性名如下图

mybatis-config

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "mybatis-3-config.dtd" >
<configuration>
	<!-- 数据库环境 -->
	<environments default="development">
		<environment id="development">
			<!-- 采用JDBC管理器方式 -->
			<transactionManager type="JDBC"/>
				<!-- POOLED采用mybatis内部连接池方式 -->
				<dataSource type="POOLED">
					<property name="driver" value="com.mysql.jdbc.Driver"/>
					<property name="username" value="root"/>
					<property name="url" value="jdbc:mysql://localhost:3306/test"/>
					<property name="password" value="1234"/>
				</dataSource>				
		</environment>
	</environments>
	<mappers>
		<mapper resource="studentMapping.xml"/>
	</mappers>
</configuration>

studentMapping.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd" >
<mapper namespace="mybatis.map">
  
  <resultMap type="entity.Student" id="student">
  		<result column="id" property="ids"/>
  		<result column="name" property="names"/>
  		<result column="password" property="passwords"/>
  		<result column="school" property="schools"/>
  		<result column="major" property="majors"/>
  </resultMap>
  
  <select id="getstudentall" resultMap="student">
  		select * from
  		t_student
  </select>
</mapper>

getAll

package test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.Properties;

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 entity.Student;

public class getAll {

	public static void main(String[] args) throws IOException {
		
		String resource = "mybatis-config.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
		SqlSession sqlSession = sqlSessionFactory.openSession();
		System.out.println(sqlSession);
		List<Student> list = sqlSession.selectList("getstudentall");
		for (int i = 0; i < list.size(); i++) {
			Student student = list.get(i);
			System.out.println(student.getIds()+"___"
					+student.getNames()+"___"
					+student.getPasswords()+"___"
					+student.getSchools()+"___"
					+student.getMajors());
		}
	}
}