Mybatis，mybatis官網

Mybatis，mybatis官網

一.Mybatis介紹

     MyBatis是一個支援普通SQL查詢，預存程序和進階映射的優秀持久層架構。MyBatis消除了幾乎所有的JDBC代碼和參數的手工設定以及對結果集的檢索封裝。MyBatis可以使用簡單的XML或註解用於配置和原始映射，將介面和Java的POJO（Plain Old Java Objects，普通的Java對象）映射成資料庫中的記錄。

二.Mybatis jar包

   需要準備的引用包

　　mybatis-3.2.8.jar：myBatis架構使用

<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>3.2.2</version>
</dependency>

　　ojdbc6.jar：資料庫連接

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-Java</artifactId>
  <version>5.1.36</version>
</dependency>

三.結構分析

　　1）需要設定檔串連資料庫；

　　2）需要公用方法提供資料庫連接的使用；

　　3）PO：持久對象

　　4）資料查詢SQL配置XML檔案；

　　5）對外介面；

四.結構搭建

樣本如下：

 

 IStudentInfoDAO.java

package cn.happy.dao;import cn.happy.entity.StudentInfo;import java.util.List;/** * Created by Happy on 2017-07-09. */public interface IStudentInfoDAO {     //01.查詢所有的學生資訊    public List<StudentInfo> findAll();    //02.根據學生學號查詢特定學生對象    public  StudentInfo getStudentById(int stuid);}

IStudentInfoDAO.xml

<?xml version="1.0" encoding="UTF-8" ?><!--標頭檔--><!DOCTYPE mapper        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"        "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <!--namespace：     命名空間：區分不同空間下的同名SQLID     A： findlAll     B:  findAll    --><mapper namespace="cn.happy.dao.IStudentInfoDAO">    <!--SQL標籤      id:唯一鎖定到SQL標識      paramenterType:SQL語句的入參  可以省略      resultType：      增刪除操作：不能 寫      查詢：單個實體的類型    -->    <select id="findAll" resultType="StudentInfo">        /*SQL文：SQL語句*/        select * from studentinfo    </select>    <!--按主鍵查詢-->    <select id="getStudentById" resultType="StudentInfo">        select * from studentinfo WHERE stuid=#{stuId}    </select></mapper>

StudentInfo.java

package cn.happy.entity;import java.util.Date;/** * Created by Happy on 2017-07-09. */public class StudentInfo {     private Integer stuId;     private String stuName;     private Integer  stuAge;     private Date stuDate;    public Integer getStuId() {        return stuId;    }    public void setStuId(Integer stuId) {        this.stuId = stuId;    }    public String getStuName() {        return stuName;    }    public void setStuName(String stuName) {        this.stuName = stuName;    }    public Integer getStuAge() {        return stuAge;    }    public void setStuAge(Integer stuAge) {        this.stuAge = stuAge;    }    public Date getStuDate() {        return stuDate;    }    public void setStuDate(Date stuDate) {        this.stuDate = stuDate;    }}

MyBatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?><!--文件類型，標頭檔--><!DOCTYPE configuration        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"        "http://mybatis.org/dtd/mybatis-3-config.dtd"><!--根節點，XMl只能有一個--><configuration>    <typeAliases>        <!--<typeAlias type="cn.happy.entity.StudentInfo" alias="StudentInfo"></typeAlias>-->        <!--將該包中的簡單類型 StudentInfo作為類的別名-->        <package name="cn.happy.entity"></package>    </typeAliases>    <!--一個environments有N個environment-->    <environments default="development">        <environment id="development">            <!--            transactionManager:JDBC保證事務的            update            delete            事務分類：JDBC:編程式事務                        xxx.beginTransaction()                        tx.commit()                        tx.rollback()                      配置式事務                      JDBC|MANAGED                      區別            -->            <transactionManager type="JDBC"/>            <!--                POOLED：MyBatis內建的串連池                c3p0串連池                        POOLED 、UNPOOLED  、JNDI            -->            <dataSource type="POOLED">                <property name="driver" value="com.mysql.jdbc.Driver"/>                <property name="url" value="jdbc:mysql://localhost:3306/y2165"/>                <property name="username" value="root"/>                <property name="password" value="root"/>            </dataSource>        </environment>    </environments>    <mappers>        <mapper resource="cn/happy/dao/IStudentInfoDAO.xml"/>    </mappers></configuration>

MyBatisTest0709.java

package cn.happy.test;import cn.happy.dao.IStudentInfoDAO;import cn.happy.entity.StudentInfo;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 java.io.IOException;import java.io.InputStream;import java.util.List;/** * Created by Happy on 2017-07-09. */public class MyBatisTest0709 {    @Test    //03.根據主鍵查詢單個對象  getMapper（）方式    public void testSelectOneByGetMapper(){        String path="MyBatis-config.xml";        InputStream is= null;        try {            is = Resources.getResourceAsStream(path);            SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(is);            SqlSession session=factory.openSession();            IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);            StudentInfo info = dao.getStudentById(3);            System.out.println(info.getStuName());            /*MyBatisTest0709 my=new MyBatisTest0709();            Class<MyBatisTest0709> clazz = (Class<MyBatisTest0709>) my.getClass();            try {                Class<MyBatisTest0709> clazzz = (Class<MyBatisTest0709>)Class.forName("cn.happy.test.MyBatisTest0709");            } catch (ClassNotFoundException e) {                e.printStackTrace();            }*/            session.close();        } catch (IOException e) {            e.printStackTrace();        }    }    @Test    //02.根據主鍵查詢單個對象    public void testSelectOne(){        String path="MyBatis-config.xml";        InputStream is= null;        try {            is = Resources.getResourceAsStream(path);            SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(is);            SqlSession session=factory.openSession();            StudentInfo info = session.selectOne("getStudentById",3);            System.out.println(info.getStuName());            session.close();        } catch (IOException e) {            e.printStackTrace();        }    }     @Test    public void testAll(){         String path="MyBatis-config.xml";         InputStream is= null;         try {             is = Resources.getResourceAsStream(path);             SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(is);             SqlSession session=factory.openSession();             List<StudentInfo> list = session.selectList("findAll");             for (StudentInfo info:list) {                 System.out.println(info.getStuName());             }             session.close();         } catch (IOException e) {             e.printStackTrace();         }     }}