个人知识管理系统Version1.0开发记录（09）

MyBatis初试

MyBatis 是支持普通 SQL查询，存储过程和高级映射的优秀持久层框架。MyBatis 消除了几乎所有的JDBC代码和参数的手工设置以及结果集的检索。

 

运用Mybatis框架修改项目，思路如下：

 

1、Oracle SQL Developer，表-》约束条件-》添加主键，实现主键自动增长。

（1）添加主键，

alter table "DYL"."COMPANY" add constraint pk_company primary key("COMPANYID") ;

（2）新建序列，

CREATE SEQUENCE  "DYL"."COMPANY_SEQUENCE"  MINVALUE 1 MAXVALUE 999999999999999999999999999 INCREMENT BY 1 START WITH 21 CACHE 20 NOORDER  NOCYCLE ;

（3）触发器-》创建序列中的主键，

begin
execute immediate 'create or replace trigger company_increase '||chr(10)||
' before insert on "DYL"."COMPANY" '||chr(10)||
' for each row '||chr(10)||
'begin '||chr(10)||
' if inserting then '||chr(10)||
' if :NEW."COMPANYID" is null then '||chr(10)||
' select COMPANY_SEQUENCE.nextval into :NEW."COMPANYID" from dual; '||chr(10)||
' end if; '||chr(10)||
' end if; '||chr(10)||
'end;'||chr(10);
end;

 

2、导入mybatis的jar包。

 

3、sqlMap-config.xml配置文件，在src目录下。每个MyBatis应用程序主要都是使用SqlSessionFactory实例的，一个SqlSessionFactory实例可以通过SqlSessionFactoryBuilder获得。SqlSessionFactoryBuilder可以从一个xml配置文件或者一个预定义的配置类的实例获得。

 <?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>

     <typeAliases>
         <typeAlias alias="Company" type="com.dyl.entity.Company"/>
         <typeAlias alias="Dep" type="com.dyl.entity.Dep"/>
         <typeAlias alias="Duty" type="com.dyl.entity.Duty"/>
         <typeAlias alias="Staff" type="com.dyl.entity.Staff"/>
     </typeAliases>

     <environments default="development">
         <environment id="development">
             <transactionManager type="JDBC" />
             <dataSource type="POOLED">
                 <property name="driver" value="oracle.jdbc.driver.OracleDriver" />
                 <property name="url" value="jdbc:oracle:thin:@127.0.0.1:1521:PKMS" />
                 <property name="username" value="DYL" />
                 <property name="password" value="DYL" />
             </dataSource>
         </environment>
     </environments>

     <mappers>
         <mapper resource="com/dyl/entity/xml/Company.xml" />

     </mappers>

 </configuration>

4、POJOs映射，Company.xml，实现数据的增删改查。MyBatis 使用简单的 XML或注解用于配置和原始映射，将接口和 Java 的POJOs（Plain Old Java Objects，普通的 Java对象）映射成数据库中的记录。

 <?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.dyl.dao.ICompanyDao">

     <select id="selectCompanyById" parameterType="BigDecimal" resultType="Company">
         select * from company where companyid = #{id}
     </select>

     <!-- 为了返回list 类型而定义的returnMap -->
     <resultMap type="Company" id="resultListCompany">
         <id column="companyId" property="companyId" />
         <result column="companyName" property="companyName" />
         <result column="address" property="address" />
         <result column="telephone" property="telephone" />
         <result column="leader" property="leader" />
         <result column="mobilePhone" property="mobilePhone" />
         <result column="remark" property="remark" />
     </resultMap>

     <!-- 返回list 的select 语句，注意 resultMap 的值是指向前面定义好的 -->
     <select id="selectCompanys" parameterType="string" resultMap="resultListCompany">
         select * from company where companyName like #{companyName} order by companyid
     </select>

     <!--执行增加操作的SQL语句。id和parameterType分别与ICompanyDao接口中的addCompany方法的名字和参数类型一致。以#{name}的形式引用Company参数
         的name属性，MyBatis将使用反射读取Company参数的此属性。#{name}中name大小写敏感。引用其他的gender等属性与此一致。useGeneratedKeys设置
         为"true"，表明要MyBatis获取由数据库自动生成的主键；keyProperty="companyid"指定把获取到的主键值注入到Company的companyid属性 -->
     <insert id="addCompany" parameterType="Company" useGeneratedKeys="true" keyProperty="companyid">
         insert into company(companyName,address,telephone,leader,mobilePhone,remark) values
         (#{companyName},#{address},#{telephone},#{leader},#{mobilePhone},#{remark})
     </insert>

     <update id="updateCompany" parameterType="Company">
         update company set companyName=#{companyName},address=#{address},telephone=#{telephone},
         leader=#{leader},mobilePhone=#{mobilePhone},remark=#{remark} where companyId=#{companyId}
     </update>

     <delete id="deleteCompany" parameterType="BigDecimal">
         delete from company where companyid=#{id}
     </delete>

 </mapper>

5、namespace="com.dyl.dao.ICompanyDao"，修改dao接口，描述参数和SQL语句的返回值。ICompanyDao里面的方法名，对应，Company.xml里面的id。

 package com.dyl.dao;

 import java.math.BigDecimal;
 import java.util.List;

 import com.dyl.entity.Company;
 /**
  * Title: 知识管理系统
  * Description: 知识管理系统1.0
  * Copyright: Copyright (c) 2010-2020
  * Company:妖灵科技
  * Created on 2014-7-7
  * @author dyl
  * @version 1.0
 */
 public interface ICompanyDao {
     /**
      * 根据分公司id查找分公司
      * @param id
      * @return
      */
     public Company selectCompanyById(BigDecimal id);
     /**
      * 查找分公司
      * @param companyName
      * @return
      */
     public List<Company> selectCompanys(String companyName);
     /**
      * 增加分公司
      * @param company
      */
     public void addCompany(Company company);
     /**
      * 修改分公司
      * @param company
      */
     public void updateCompany(Company company);
     /**
      * 删除分公司
      * @param id
      */
     public void deleteCompany(BigDecimal id);

 }

6、测试dao接口。

 package com.dyl.test;

 import java.io.Reader;
 import java.math.BigDecimal;
 import java.util.List;

 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 com.dyl.dao.ICompanyDao;
 import com.dyl.entity.Company;
 /**
  * 测试类
  * Title: 知识管理系统
  * Description: 知识管理系统1.0
  * Copyright: Copyright (c) 2010-2020
  * Company:妖灵科技
  * Created on 2014-7-7
  * @author dyl
  * @version 1.0
  */
 public class CompanyXmlTest {
     private static SqlSessionFactory sqlSessionFactory;
     private static Reader reader;

     static {
         try {
             reader = Resources.getResourceAsReader("sqlMap-config.xml");
             sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     public static SqlSessionFactory getSession() {
         return sqlSessionFactory;
     }

     /**
      * 查找分公司
      * @param companyName
      */
     public void getCompanyList(String companyName){
         SqlSession session = sqlSessionFactory.openSession();
         try {
             ICompanyDao companyDao=session.getMapper(ICompanyDao.class);
             List<Company> companys = companyDao.selectCompanys(companyName);
             for(Company company:companys){
                 System.out.println(company.getCompanyId().toString()+"，"+company.getCompanyName()+"，"+company.getAddress());
             }
         } finally {
             session.close();
         }
     }

     /**
      * 测试增加，增加后，必须提交事务，否则不会写入到数据库。
      */
     public void addCompany(){
         Company company=new Company();
         company.setCompanyName("妖灵科技");
         company.setAddress("四川成都");
         company.setTelephone("028-88888888");
         company.setLeader("妖灵");
         company.setMobilePhone("18888888888");
         company.setRemark("HO");
         SqlSession session = sqlSessionFactory.openSession();
         try {
             ICompanyDao companyDao=session.getMapper(ICompanyDao.class);
             companyDao.addCompany(company);
             session.commit();
         } finally {
             session.close();
         }
     }
     /**
      * 先得到公司，然后修改，提交。
      */
     public void updateCompany(){
         SqlSession session = sqlSessionFactory.openSession();
         try {
             ICompanyDao companyDao=session.getMapper(ICompanyDao.class);
             Company company=companyDao.selectCompanyById(new BigDecimal(2));
             company.setAddress("北京");
             companyDao.updateCompany(company);
             session.commit();
         } finally {
             session.close();
         }
     }

     /**
      * 删除数据，删除一定要commit。
      * @param id
      */
     public void deleteCompany(BigDecimal id){
         SqlSession session = sqlSessionFactory.openSession();
         try {
             ICompanyDao companyDao=session.getMapper(ICompanyDao.class);
             companyDao.deleteCompany(id);
             session.commit();
         } finally {
             session.close();
         }
     }

     public static void main(String[] args) {
         SqlSession session = sqlSessionFactory.openSession();
         try {
             ICompanyDao companyDao=session.getMapper(ICompanyDao.class);

 //            // 根据分公司id查找分公司
 //            Company company=companyDao.selectCompanyById(new BigDecimal(5));
 //            System.out.println(company.getCompanyName());
 //            System.out.println(company.getAddress());
 //            System.out.println();

 //            // 查找分公司
 //            CompanyTest companyTest=new CompanyTest();
 //            companyTest.getCompanyList("%");
 //            System.out.println();

             // 增加分公司
             Company company=new Company();
             company.setCompanyName("海口分公司");
             company.setAddress("海南海口");
             company.setTelephone("0898-88888888");
             company.setLeader("碧波");
             company.setMobilePhone("18888888888");
             company.setRemark("东方夏威夷");
             companyDao.addCompany(company);
             session.commit();
             System.out.println("当前增加的公司名称为:"+company.getCompanyName());

 //            // 修改分公司
 //            Company company=companyDao.selectCompanyById(new BigDecimal(4));
 //            company.setAddress("天津");
 //            company.setCompanyName("天津分公司");
 //            company.setLeader("闻其");
 //            company.setMobilePhone("18888888888");
 //            company.setRemark("首都门户");
 //            company.setTelephone("022-88888888");
 //            companyDao.updateCompany(company);
 //            session.commit();
 //            System.out.println("修改成功");

 //            // 删除分公司
 //            companyDao.deleteCompany(new BigDecimal(5));
 //            session.commit();
 //            System.out.println("删除成功");

         } finally {
             session.close();
         }
     }
 }

7、修改dao实现类。

 package com.dyl.dao.impl;

 import java.io.Reader;
 import java.math.BigDecimal;
 import java.util.List;

 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 com.dyl.dao.ICompanyDao;
 import com.dyl.entity.Company;
 /**
  * 数据持久层实现类
  * Title: 知识管理系统
  * Description: 知识管理系统1.0
  * Copyright: Copyright (c) 2010-2020
  * Company:妖灵科技
  * Created on 2014-7-7
  * @author dyl
  * @version 1.0
  */
 public class CompanyDaoImpl implements ICompanyDao{

     private static SqlSessionFactory sqlSessionFactory;
     private static Reader reader;

     static {
         try {
             reader = Resources.getResourceAsReader("sqlMap-config.xml");
             sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     public static SqlSessionFactory getSession() {
         return sqlSessionFactory;
     }

     SqlSession session = sqlSessionFactory.openSession();
     ICompanyDao companyDao=session.getMapper(ICompanyDao.class);

     public Company selectCompanyById(BigDecimal id) {
         return companyDao.selectCompanyById(id);
     }

     public List<Company> selectCompanys(String companyName) {
         return companyDao.selectCompanys(companyName);
     }

     public void addCompany(Company company) {
         companyDao.addCompany(company);
         session.commit();
         session.close();
     }

     public void updateCompany(Company company) {
         companyDao.updateCompany(company);
         session.commit();
         session.close();
     }

     public void deleteCompany(BigDecimal id) {
         companyDao.deleteCompany(id);
         session.commit();
         session.close();
     }
 }

8、修改工厂。

 package com.dyl.util;

 import com.dyl.dao.impl.CompanyDaoImpl;
 import com.dyl.dao.impl.CompanyDaoJdbcImpl;
 import com.dyl.dao.impl.DepDaoJdbcImpl;
 import com.dyl.dao.impl.DutyDaoJdbcImpl;
 import com.dyl.dao.impl.OneDsDaoJdbcImpl;
 import com.dyl.dao.impl.StaffDaoJdbcImpl;
 /**
  * 工厂设计模式：为调用者提供符合接口要求的对象,方便我们以后采用框架技术进行底层数据访问。
  * Title: 知识管理系统
  * Description: 知识管理系统1.0
  * Copyright: Copyright (c) 2010-2020
  * Company:妖灵科技
  * Created on 2014-7-7
  * @author dyl
  * @version 1.0
  */
 public class Factory {
     public static Object getInstance(String type) {
         Object obj = null;
         if ("IOneDsDAO".equals(type)) {
             obj = new OneDsDaoJdbcImpl();

         } else if ("ICompanyDao".equals(type)) {
             obj = new CompanyDaoImpl();

         } else if ("IDepDao".equals(type)) {
             obj = new DepDaoJdbcImpl();
         } else if ("IDutyDao".equals(type)) {
             obj = new DutyDaoJdbcImpl();
         } else if ("IStaffDao".equals(type)) {
             obj = new StaffDaoJdbcImpl();
         }
         return obj;
     }
 }

9、修改service接口。

 package com.dyl.service;

 import java.math.BigDecimal;
 import java.util.List;

 import com.dyl.entity.Company;

 public interface ICompanyService {
     public Company selectCompanyById(BigDecimal id);// 根据分公司id查找分公司

     public List<Company> selectCompanys(String companyName);// 查找分公司

     public void addCompany(Company company);// 增加分公司

     public void updateCompany(Company company);// 修改分公司

     public void deleteCompany(BigDecimal id);// 删除分公司
 }

10、修改service实现类。

 package com.dyl.service.impl;

 import java.math.BigDecimal;
 import java.util.List;

 import com.dyl.dao.ICompanyDao;
 import com.dyl.entity.Company;
 import com.dyl.service.ICompanyService;
 import com.dyl.util.Factory;

 public class CompanyServiceImpl implements ICompanyService {

     ICompanyDao dao=(ICompanyDao) Factory.getInstance("ICompanyDao");

     public Company selectCompanyById(BigDecimal id) {
         return dao.selectCompanyById(id);
     }

     public List<Company> selectCompanys(String companyName) {
         return dao.selectCompanys(companyName);
     }

     public void addCompany(Company company) {
         dao.addCompany(company);
     }

     public void updateCompany(Company company) {
         dao.updateCompany(company);
     }

     public void deleteCompany(BigDecimal id) {
         dao.deleteCompany(id);
     }
 }

11、测试service实现类。

 package com.dyl.test;

 import java.util.List;

 import com.dyl.entity.Company;
 import com.dyl.service.ICompanyService;
 import com.dyl.service.impl.CompanyServiceImpl;

 public class CompanyServiceImplTest {
     public static void main(String[] args) {
         ICompanyService cs=new CompanyServiceImpl();
         List<Company>companys=cs.selectCompanys("%");
         System.out.println(companys.size());
         for(Company company:companys){
             System.out.println(company.getCompanyId().toString()+"，"+company.getCompanyName()+"，"+company.getAddress());
         }
     }
 }

12、工程结构图如下。

我们接下来需要完成：（1）修改控制层和显示层。（2）分页。（3）动态sql。（4）修改dep、duty、staff。（5）多表关联数据查询。OK，我们下次见。