韓順平__jsp和selverlt原完整版課件_筆記

1、java ee j2ee視頻教程 - jsp作者: 韓順平 (一)jsp第3講1.用戶登錄系統(tǒng)框架改良1.0 model1(純jsp)開發(fā)模式的反思1.1 model1(結(jié)合java class)開發(fā)模式2. 用戶登錄系統(tǒng)框架再改良2.1 mvc開發(fā)模式(二)用戶登錄系統(tǒng)框架改良(三)用戶登錄系統(tǒng)框架改良Login.jspConDB.javaUserbeanCl.java(操作表的)Wel.jspUserbean.java(對應(yīng)一個(gè)表)LoginCl.jspdatabaseView層Model層一張表對應(yīng)兩個(gè)類,其中一個(gè)表類一個(gè)就是表處理類,(四)用戶登錄系統(tǒng)框架改良原因在1.2(五)用戶登錄

2、系統(tǒng)框架改良六用戶登錄系統(tǒng)框架改良/ 調(diào)用UserBeanCl的fenye方法,完成分頁顯示就是指創(chuàng)立一個(gè)UserBeanCl的實(shí)例,然后調(diào)用他的某個(gè)方法(七)用戶登錄系統(tǒng)框架再改良Servlet的跳轉(zhuǎn)時(shí)最快的!(八)用戶登錄系統(tǒng)框架再改良Mvc是一個(gè)模式,強(qiáng)制地使輸入處理與輸出分開.分為模型視圖和控制器!Mvc m=model 只要是javaclassv =view 主要是jsp c=controller 只要是servlet來做的(九)用戶登錄系統(tǒng)框架再改良(十)用戶登錄系統(tǒng)框架再改良Mvc框架是很嚴(yán)格的是不允許jsp直接調(diào)用javaclass文件中間必須要經(jīng)過servlet做中間控制層!

3、(十一)用戶登錄系統(tǒng)框架再改良(十二)用戶登錄系統(tǒng)框架再改良(十三)用戶登錄系統(tǒng)框架再改良(十四)用戶登錄系統(tǒng)框架再改良附代碼:界面層:Login.JSP base href= My JSP Login.jsp starting page !- 用戶登錄 用戶名: 密碼: Wel.jsp base href= My JSP Wel.jsp starting page !- 恭喜!登陸成功! 返回重新登錄 用戶信息列表 用戶編號用戶名用戶密碼電子郵件等級 % for (int i =0;i a href=UserClServlet?pageNow=1&username=第一頁 a href=Us

4、erClServlet?pageNow=&username=上一頁 % /顯示超鏈接 for (int i=1;i a href=UserClServlet?pageNow=&username= a href=UserClServlet?pageNow=&username=下一頁 a href=UserClServlet?pageNow=&username=最后一頁 控制層:LoginCl.java/這是一個(gè)控制器,主要完成對用戶身份的驗(yàn)證/本身并不實(shí)際完成身份驗(yàn)證的業(yè)務(wù)邏輯,而是去調(diào)model的業(yè)務(wù)邏輯完成對數(shù)據(jù)處理.package com.hao.controller;import jav

5、a.io.IOException;import java.io.PrintWriter;import java.util.ArrayList;import javax.servlet.ServletException;import javax.servlet. . Servlet;import javax.servlet. . ServletRequest;import javax.servlet. . ServletResponse;import com.hao.model.*;public class LoginCl extends Servlet /* * The doGet metho

6、d of the servlet. * * This method is called when a form has its tag value method equals to get. * * param request the request send by the client to the server * param response the response send by the server to the client * throws ServletException if an error occurred * throws IOException if an erro

7、r occurred */public void doGet( ServletRequest request, ServletResponse response)throws ServletException, IOException /得到用戶名和密碼String username=request.getParameter(username);String password=request.getParameter(password);/使用模型UserBeanCl,完成對用戶身份的驗(yàn)證/創(chuàng)立UserBeanCl對象UserBeanCl ubc=new UserBeanCl();/調(diào)用方法i

8、f (ubc.checkUser(username, password)/登陸成功!/這種跳轉(zhuǎn)為轉(zhuǎn)向/response.sendRedirect(Wel.jsp);/在跳轉(zhuǎn)到Wel.jsp頁面前就要把要顯示的數(shù)據(jù)就要準(zhǔn)備好!ArrayList al =ubc.fenye(1);int pageCount =ubc.getPageCount();/將al pageCount放入request中.request.setAttribute(al, al);request.setAttribute(pageCount, pageCount);request.setAttribute(pageNow,

9、1);/因?yàn)閟endRedirect跳轉(zhuǎn)的效率不高,在公司里常常用轉(zhuǎn)發(fā)的方法./這種轉(zhuǎn)發(fā)效率高,并且request中的對象還可以在下個(gè)頁面中使用/在本案例中request對象指的是上面的兩句話result和pageCountrequest.getRequestDispatcher(Wel.jsp).forward(request, response);else/登錄失敗!/response.sendRedirect(Login.jsp);request.getRequestDispatcher(Login.jsp).forward(request, response);/* * The doP

10、ost method of the servlet. * * This method is called when a form has its tag value method equals to post. * * param request the request send by the client to the server * param response the response send by the server to the client * throws ServletException if an error occurred * throws IOException

11、if an error occurred */public void doPost( ServletRequest request, ServletResponse response)throws ServletException, IOException this.doGet(request, response);UserClServlet.java/處理用戶的分頁顯示/也用于處理用戶的增刪改package com.hao.controller;import java.io.IOException;import com.hao.model.*;import java.io.PrintWrit

12、er;import java.util.ArrayList;import javax.servlet.ServletException;import javax.servlet. . Servlet;import javax.servlet. . ServletRequest;import javax.servlet. . ServletResponse;public class UserClServlet extends Servlet /* * The doGet method of the servlet. * * This method is called when a form ha

13、s its tag value method equals to get. * * param request the request send by the client to the server * param response the response send by the server to the client * throws ServletException if an error occurred * throws IOException if an error occurred */public void doGet( ServletRequest request, Se

14、rvletResponse response)throws ServletException, IOException this.doPost(request, response);/* * The doPost method of the servlet. * * This method is called when a form has its tag value method equals to post. * * param request the request send by the client to the server * param response the respons

15、e send by the server to the client * throws ServletException if an error occurred * throws IOException if an error occurred */public void doPost( ServletRequest request, ServletResponse response)throws ServletException, IOException try/得到pageNow int pageNow =Integer.parseInt(request.getParameter(pag

16、eNow).toString();UserBeanCl ubc =new UserBeanCl();/在跳轉(zhuǎn)到Wel.jsp頁面前就要把要顯示的數(shù)據(jù)就要準(zhǔn)備好!ArrayList al =ubc.fenye(pageNow);int pageCount =ubc.getPageCount();/將al pageCount放入request中./說明這里寫成setAttribute那么在下也就要用getAttribute來接受/如果是參數(shù)就要用getParameter來接受,不能搞混咯!request.setAttribute(pageCount, pageCount+);request.set

17、Attribute(al, al);request.setAttribute(pageNow, pageNow);/重新跳回Wel.jsprequest.getRequestDispatcher(Wel.jsp).forward(request, response);catch (Exception ex)ex.printStackTrace();finally/System.out.println(這是UserClServlet的測試finally);業(yè)務(wù)邏輯層:ConDB.java/當(dāng)一段代碼被使用三次以上就應(yīng)該把這樣的代碼封裝到一個(gè)函數(shù)里面package com.hao.model;im

18、port java.sql.*;public class ConDB private Connection ct=null;public Connection getct()Connection con=null;try /1加載驅(qū)動 String driver=com.microsoft.sqlserver.jdbc.SQLServerDriver;String url=jdbc:sqlserver:/127.0.0.1:1433;databaseName=spdb;Class.forName(driver);con =DriverManager.getConnection (url,sa,

19、hao123);catch (Exception ex)ex.printStackTrace();finallyreturn con ;UserBean.java/這是一個(gè)javaBean對應(yīng)Users表數(shù)據(jù)./表中有幾個(gè)字段,那么這個(gè)java中就有多少個(gè)私有屬性/他的一個(gè)實(shí)例代表一個(gè)USers表中的一條記錄.package com.hao.model;public class UserBean private int userId;private String userName;public String getUserName() return userName;public void s

20、etUserName(String userName) this.userName = userName;public String getPasswd() return passwd;public void setPasswd(String passwd) this.passwd = passwd;public String getEmail() return email;public void setEmail(String email) this.email = email;public int getGrade() return grade;public void setGrade(i

21、nt grade) this.grade = grade;private String passwd;private String email;private int grade;public void setUserId(int userId) this.userId = userId;public int getUserId() return userId;UserBeanCl.java/這是一個(gè)處理類,有些人喜歡把它叫做BO business object /主要是封裝users表的各種操作增加刪除修改查詢.package com.hao.model;import java.sql.*;

22、import java.util.*;public class UserBeanCl private Connection ct =null;private Statement sm =null;private ResultSet rs =null;private int pageSize=3;private int rowCount=0;/從數(shù)據(jù)庫中得到private int pageCount =0;/一共有多少頁 通過pageSize和rowCount獲得./得到總頁數(shù)public int getPageCount()try/得到連接ct =new ConDB().getct();/3創(chuàng)

23、立Statement sm=ct.createStatement();/4查詢 rs=sm.executeQuery(select count(*) from users );if(rs.next()rowCount =rs.getInt(1);/計(jì)算pageCountpageCount=(rowCount+pageSize-1)/pageSize;catch (Exception ex)ex.printStackTrace();finallythis.closed();return pageCount ;/分頁函數(shù)public ArrayList fenye ( int pageNow)ArrayList al =new ArrayList();try/得到連接ct =new ConDB().getct();/3創(chuàng)立Statement sm=ct.createStatement();/查詢出需要顯示的記錄. rs=sm.executeQuery(select top +pageSize + * from users where userid not in ( select top +pageSize*(pageNow-1)+ userid f