Mybatis学习与使用

MyBatis

一、前言    

最近学习了经典框架Mybatis，为了能后更好的，有效的学习与使用，现做笔记如下：MyBatis 是一个可以自定义SQL、存储过程和高级映射的持久层框架。MyBatis 摒除了大部分的JDBC代码、手工设置参数和结果集重获。MyBatis 只使用简单的XML 和注解来配置和映射基本数据类型、Map 接口和POJO 到数据库记录。相对Hibernate和Apache OJB等“一站式”ORM解决方案而言，Mybatis 是一种“半自动化”的ORM实现。

二、工程目录

三、代码

Dept.java:

package bean;public class Dept {private int deptno;private String dname;private String loc;public Dept(){}public Dept(int deptno, String dname, String loc) {super();this.deptno = deptno;this.dname = dname;this.loc = loc;}public int  getDeptno() {return deptno;}public void setDeptno(int deptno) {this.deptno = deptno;}public String getDname() {return dname;}public void setDname(String dname) {this.dname = dname;}public String getLoc() {return loc;}public void setLoc(String loc) {this.loc = loc;}@Overridepublic String toString() {return "Dept [deptno=" + deptno + ", dname=" + dname + ", loc=" + loc+ "]";}}

Dept.xml:

<?xml version="1.0" encoding="UTF-8" ?>  <!DOCTYPE mapper PUBLIC "-//ibatis.apache.org//DTD Mapper 3.0//EN" "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd"><mapper namespace="mapper.DeptMapper"><insert id="addDept" parameterType="bean.Dept">insert into T_dept values(#{deptno},#{dname},#{loc})</insert><update id="updateDept" parameterType="bean.Dept">update T_dept set  deptno=#{deptno},dname=#{dname},loc=#{loc} where deptno=#{deptno}</update><delete id="deleteDept" parameterType="int">    delete from T_dept where deptno=#{deptno}</delete><select id="findDept" parameterType="int" resultType="bean.Dept">    select * from T_dept where deptno=#{deptno}</select><select id="findAllDept" resultType="bean.Dept">select * from T_dept</select></mapper>

DeptMapper.java:

package mapper;import java.util.List;import bean.Dept;public interface DeptMapper {void addDept(Dept dept);void updateDept(Dept dept);void deleteDept(int detpno);Dept findDept(int deptno);List<Dept> findAllDept();}

Test.java:

package test;import java.io.IOException;import java.io.Reader;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;public class Test {public static void main(String[] args) {try {Reader reader=Resources.getResourceAsReader("SqlMapConfig.xml");SqlSessionFactoryBuilder sfb=new SqlSessionFactoryBuilder();SqlSessionFactory sf=sfb.build(reader);SqlSession session =sf.openSession();System.out.println(session);session.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

TestMapper.java:

package test;import java.io.IOException;import java.io.Reader;import java.util.List;import mapper.DeptMapper;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.RowBounds;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import bean.Dept;public class TestMapper {public static void main(String[] args) {//findByPage(); // 分页查询try {Reader reader=Resources.getResourceAsReader("SqlMapConfig.xml");SqlSessionFactoryBuilder sfb=new SqlSessionFactoryBuilder();SqlSessionFactory sf=sfb.build(reader);SqlSession session =sf.openSession();    //通过接口创建实现类。进而通过接口引用   ，创建的时候应该是和Dept.xml的方法有关DeptMapper mapper=session.getMapper(mapper.DeptMapper.class);List<Dept> lists=mapper.findAllDept();System.out.println(lists);session.commit();session.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public static void addDept(){try {Reader reader=Resources.getResourceAsReader("SqlMapConfig.xml");SqlSessionFactoryBuilder sfb=new SqlSessionFactoryBuilder();SqlSessionFactory sf=sfb.build(reader);SqlSession session =sf.openSession();Dept dept=new Dept(1002,"wtf","beijing");session.insert("addDept",dept);System.out.println("sucess");session.commit();session.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public static void updateDept(){try {Reader reader=Resources.getResourceAsReader("SqlMapConfig.xml");SqlSessionFactoryBuilder sfb=new SqlSessionFactoryBuilder();SqlSessionFactory sf=sfb.build(reader);SqlSession session =sf.openSession();Dept dept=new Dept(1002,"wtfxhs","beijing");session.update("updateDept",dept);System.out.println("sucess");session.commit();session.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public static void deleteDept(){try {Reader reader=Resources.getResourceAsReader("SqlMapConfig.xml");SqlSessionFactoryBuilder sfb=new SqlSessionFactoryBuilder();SqlSessionFactory sf=sfb.build(reader);SqlSession session =sf.openSession();int dept=1002;session.delete("deleteDept",dept);System.out.println("sucess");session.commit();session.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public static void findDept(){try {Reader reader=Resources.getResourceAsReader("SqlMapConfig.xml");SqlSessionFactoryBuilder sfb=new SqlSessionFactoryBuilder();SqlSessionFactory sf=sfb.build(reader);SqlSession session =sf.openSession();int dept=1003;Dept depts=session.selectOne("findDept",dept);System.out.println(depts);session.commit();session.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public static void findAllDept(){try {Reader reader=Resources.getResourceAsReader("SqlMapConfig.xml");SqlSessionFactoryBuilder sfb=new SqlSessionFactoryBuilder();SqlSessionFactory sf=sfb.build(reader);SqlSession session =sf.openSession();List<Dept> lists=session.selectList("findAllDept");for(Dept dept :lists){System.out.println(dept);}session.commit();session.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}//分页查询public static void findByPage(){try {Reader reader=Resources.getResourceAsReader("SqlMapConfig.xml");SqlSessionFactoryBuilder sfb=new SqlSessionFactoryBuilder();SqlSessionFactory sf=sfb.build(reader);SqlSession session =sf.openSession();RowBounds r=new RowBounds(2, 3);List<Dept> lists=session.selectList("findAllDept",null,r);for(Dept dept :lists){System.out.println(dept);}session.commit();session.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

mabatis.sql:

select * from T_dept;create table T_dept(   deptno number(4) primary key,   dname varchar2(20),   loc varchar2(40));insert into T_dept values(1001,'Obelia','haerbin');insert into T_dept values(1002,'Obelia','haerbin');insert into T_dept values(1004,'Obelia','haerbin');insert into T_dept values(1005,'Obelia','haerbin');insert into T_dept values(1006,'Obelia','haerbin');insert into T_dept values(1007,'Obelia','haerbin');insert into T_dept values(1008,'Obelia','haerbin');update  T_dept set  deptno=1003,dname='helloworld',loc='nanjing' where deptno=1001;delete  from T_dept where deptno=1003;

SqlMapConfig.xml:

<?xml version="1.0" encoding="UTF-8" ?>  <!DOCTYPE configuration PUBLIC "-//ibatis.apache.org//DTD Config 3.0//EN" "http://ibatis.apache.org/dtd/ibatis-3-config.dtd"><configuration><environments default="environment"><environment id="environment"><transactionManager type="JDBC" /><dataSource type="POOLED"><property name="driver" value="oracle.jdbc.driver.OracleDriver" /><property name="url"value="jdbc:oracle:thin:@localhost:1521:orcl" /><property name="username" value="scott" /><property name="password" value="xhs12302" /></dataSource></environment></environments><mappers><mapper resource="bean/Dept.xml"/></mappers></configuration> 

四、截图

        运行Test.java，如下：   

    

       运行TestMapper.java，如下：

 小细节：1、自定义映射

       

                2、注解配置

    

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