2.MyBatis有代理增删改

2.1 创建一个javaweb项目MyBatis_Part1，并创建如下sql脚本

 create user holly identified by sys;
 grant dba to holly;
 conn holly/sys
 create table teacher(id number primary key,tname varchar2(20),pwd varchar2(20));
 create sequence seq_teacher;
 insert into teacher values(seq_teacher.nextval,'holly','');
 insert into teacher values(seq_teacher.nextval,'石头','');
 insert into teacher values(seq_teacher.nextval,'朱亚楠','');
 insert into teacher values(seq_teacher.nextval,'陈明','');
 commit;

2.2 在项目的src下创建Configuration.xml主配置文

 <?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>
    <!-- 路径别名配置 -->
    <typeAliases>
      <typeAlias type="com.entity.Dept" alias="Dept"/>
    </typeAliases>

    <!-- 链接数据库的环境配置，development开发模式 -->
    <environments default="development">
       <environment id="development">
         <!-- jdbc管理事务 -->
         <transactionManager type="jdbc"/>
         <!-- 数据源配置 -->
         <dataSource type="POOLED">
            <property name="driver" value="oracle.jdbc.driver.OracleDriver"/>
            <property name="url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/>
            <property name="username" value="scott"/>
            <property name="password" value="tiger"/>
         </dataSource>

       </environment>
    </environments>
    <!-- 注册映射文件 -->
    <mappers>
      <mapper resource="com/mapper/DeptMapper.xml"/>
    </mappers>

 </configuration>

2.3 在src下的com.entity包下创建Teacher.java实体类

 package com.entity;

 public class Teacher {
     private int id;
     private String tname;
     private String pwd;
     public Teacher() {
     }

     public Teacher(String tname, String pwd) {
         this.tname = tname;
         this.pwd = pwd;
     }

     public Teacher(int id, String tname, String pwd) {
         this.id = id;
         this.tname = tname;
         this.pwd = pwd;
     }

     public int getId() {
         return id;
     }

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

     public String getTname() {
         return tname;
     }

     public void setTname(String tname) {
         this.tname = tname;
     }

     public String getPwd() {
         return pwd;
     }

     public void setPwd(String pwd) {
         this.pwd = pwd;
     }

     @Override
     public String toString() {
         return "Teacher [id=" + id + ", pwd=" + pwd + ", tname=" + tname + "]";
     }
 }

Teacher.java

2.4 在src下的com.mapper包下创建TeacherMapper.java映射接口

 package com.mapper;

 import java.util.List;

 import com.entity.Teacher;

 public interface TeacherMapper {
     //1.查所有
     List<Teacher> findAll();
     //2.根据id查询
     Teacher findById(int id);
     //3.添加
     int saveTeacher(Teacher teacher);
     //4.修改
     int updateTeacher(Teacher teacher);
     //5.删除
     int deleteTeacher(int id);

 }

TeacherMapper.java

2.5在src下的com.mapper包下创建TeacherMapper.xml映射配置文件

 <?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" >
 <!-- 如果是有代理，则namespace的值必须是映射接口的全路径 -->
 <mapper namespace="com.mapper.TeacherMapper">
   <!-- 1.查询所有 -->
   <select id="findAll" resultType="Teacher">
     select * from teacher
   </select>

   <!-- 2.根据id查询所有 -->
   <select id="findById" resultType="Teacher" parameterType="int">
     select * from teacher where id=#{id}
   </select>

   <!-- 3.添加 -->
   <insert id="saveTeacher" parameterType="Teacher">
     insert into teacher values(seq_teacher.nextval,#{tname},#{pwd})
   </insert>

   <!-- 4.修改 -->
   <update id="updateTeacher" parameterType="Teacher">
     update teacher set tname=#{tname},pwd=#{pwd}
   </update>

   <!-- 5.删除 -->
   <delete id="deleteTeacher" parameterType="int">
     delete from teacher where id=#{id}
   </delete>
 </mapper>

TeacherMapper.xml

2.6在src下的com.mapper.impl包下创建TeacherMapperImpl.java映射实现类文件

 package com.mapper.impl;

 import java.util.List;

 import org.apache.ibatis.session.SqlSession;

 import com.entity.Teacher;
 import com.mapper.TeacherMapper;
 import com.util.MyBatisUtil;

 public class TeacherMapperImpl implements TeacherMapper {
     /**
      *1.查询所有
      *     */
     public List<Teacher> findAll() {
         SqlSession sqlsession=MyBatisUtil.getSqlSession(false);
         //利用反射产生代理对象（动态代理）
         TeacherMapper mapper=sqlsession.getMapper(TeacherMapper.class);
         try {
             List<Teacher> list=mapper.findAll();
             sqlsession.close();
             return list;
         } catch (Exception e) {
             e.printStackTrace();
             return null;
         }

     }
     /**
      * 2.查询单条
      */
     public Teacher findById(int id) {
         SqlSession sqlsession=MyBatisUtil.getSqlSession(false);
         TeacherMapper mapper=sqlsession.getMapper(TeacherMapper.class);
         Teacher teacher=null;
         try {
             teacher = mapper.findById(id);
             sqlsession.close();
             return teacher;
         } catch (Exception e) {
             e.printStackTrace();
             return null;
         }
     }
     /**
      * 添加
      */
     public int saveTeacher(Teacher teacher) {
         SqlSession sqlsession=MyBatisUtil.getSqlSession(true);
         TeacherMapper mapper=sqlsession.getMapper(TeacherMapper.class);
         try {
             int num=mapper.saveTeacher(teacher);
             sqlsession.close();
             return num;
         } catch (Exception e) {
             e.printStackTrace();

             return 0;
         }
     }
    /**
     * 4.修改
     */
     public int updateTeacher(Teacher teacher) {
         SqlSession sqlsession=MyBatisUtil.getSqlSession(false);
         TeacherMapper mapper=sqlsession.getMapper(TeacherMapper.class);
         try {
             int num=mapper.updateTeacher(teacher);
             sqlsession.close();
             return num;
         } catch (Exception e) {
             e.printStackTrace();
             return 0;
         }
     }
     /**
      * 5.根据id删除
      */
     public int deleteTeacher(int id) {
         SqlSession sqlsession=MyBatisUtil.getSqlSession(false);
         TeacherMapper mapper=sqlsession.getMapper(TeacherMapper.class);
         try {
             int num=mapper.deleteTeacher(id);
             sqlsession.close();
             return num;
         } catch (Exception e) {
             e.printStackTrace();
             return 0;
         }
     }

 }

TeacherMapperImpl.java