一、配置环境
使用MyBatis框架非常简单,只需在应用程序中引入MyBatis的核心包和lib目录中的依赖包即可。
二、创建项目
需要用到的包有Mybatis、jdbc驱动包、Junit5(eclipse自带)
注意:StudentMapper.xml是创建在Pojo包里,而mybatis-cofigure.xml是创建在src下
三、贴代码
log4j.properties
# Global logging configuration
log4j.rootLogger=ERROR, stdout
# MyBatis logging configuration...
log4j.logger.com.ssm=DEBUG
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
Student.java
package Pojo;
public class Student {
private Integer id;
private String name;
private Integer age;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
}
}
StudentMapper.xml
<?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">
<!-- namespace表示命名空间 -->
<mapper namespace="Pojo.StudentMapper">
<!--根据客户编号获取客户信息 -->
<select id="findStudentById" parameterType="Integer"
resultType="Pojo.Student">
select * from t_student where id = #{id}
</select>
</mapper>
MybatisTest.java
package test;
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.Test;
import Pojo.Student;
/**
* 入门程序测试类
*/
public class MybatisTest {
/**
* 根据客户编号查询客户信息
*/
@Test
public void findStudentByIdTest() throws Exception {
// 1、读取配置文件
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
// 2、根据配置文件构建SqlSessionFactory
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(inputStream);
// 3、通过SqlSessionFactory创建SqlSession
SqlSession sqlSession = sqlSessionFactory.openSession();
// 4、SqlSession执行映射文件中定义的SQL,并返回映射结果,这个是查询单个id
Student student = sqlSession.selectOne("Pojo" + ".StudentMapper.findStudentById", 1);
// 打印输出结果
System.err.println("查询结果如下:");
System.out.println(student.toString());
// 5、关闭SqlSession
sqlSession.close();
}
}
在navicat创建一个叫mybatis的数据库,新建表t_student.
写进几条记录
mybatis-configure.xml
<?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>
<!--1.配置环境 ,默认的环境id为mysql-->
<environments default="mysql">
<!--1.2.配置id为mysql的数据库环境 -->
<environment id="mysql">
<!-- 使用JDBC的事务管理 -->
<transactionManager type="JDBC" />
<!--数据库连接池 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://127.0.0.1/mybaits" />
<property name="username" value="root" />
<property name="password" value="1234" />
</dataSource>
</environment>
</environments>
<!--2.配置Mapper的位置 -->
<mappers>
<mapper resource="Pojo/StudentMapper.xml" />
</mappers>
</configuration>
在MybatisTest.java 右键 run as -----Junit test
运行截图: