mybatis的使用

Posted 2021-01-01 jas0

简单的介绍一下mybatis的使用

采用的是maven的方式

 <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
 </dependency>    
  <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
  </dependency>

一、mybatis-config.xml的配置文件书写

<?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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://xxxxxxxxxx:3306/test?characterEncoding=UTF-8"/>
                <property name="username" value="xxxxx"/>
                <property name="password" value="xxxxx"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="mybatisMapping/studentMapper.xml"/>
    </mappers>
</configuration>

二、bean的书写

package com.jas.mybatis.bean;

public class StudentPO {
    private Integer id;
    private Integer courseId;
    private Integer studentId;
    private Integer ceId;
    private Integer addtime;
    private Integer modtime;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Integer getCourseId() {
        return courseId;
    }

    public void setCourseId(Integer courseId) {
        this.courseId = courseId;
    }

    public Integer getStudentId() {
        return studentId;
    }

    public void setStudentId(Integer studentId) {
        this.studentId = studentId;
    }

    public Integer getCeId() {
        return ceId;
    }

    public void setCeId(Integer ceId) {
        this.ceId = ceId;
    }

    public Integer getAddtime() {
        return addtime;
    }

    public void setAddtime(Integer addtime) {
        this.addtime = addtime;
    }

    public Integer getModtime() {
        return modtime;
    }

    public void setModtime(Integer modtime) {
        this.modtime = modtime;
    }
}

三、beanMapper的书写

<?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.jas.mybatis.dao.IStudentDAO">
    <select id="selectByCourseId" resultType="com.jas.mybatis.bean.StudentPO">
        SELECT * FROM test.student WHERE course_id = #{courseId}
    </select>
</mapper>

四、dao的书写

package com.jas.mybatis.dao;

import com.jas.mybatis.bean.StudentPO;
import org.apache.ibatis.annotations.Param;

import java.util.List;

public interface IStudentDAO {

    List<StudentPO> selectByCourseId(@Param("courseId") Integer courseId);
}

五、test的运行

package com.jas.mybatis.test;

import com.alibaba.fastjson.JSONObject;
import com.jas.mybatis.bean.StudentPO;
import com.jas.mybatis.dao.IStudentDAO;
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 java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class test1 {
    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();
        try {
            IStudentDAO studentDAO = sqlSession.getMapper(IStudentDAO.class);
            List<StudentPO> productList = studentDAO.selectByCourseId(10);
            System.out.println(JSONObject.toJSONString(productList));
        } finally {
            sqlSession.close();
        }

    }
}