Developing a Web site using the MVC pattern

Read the Hanshunping of the Java EE video, bar inside taught to do out, feel great, novice road!!!

This certainly is not original, but is not reproduced, then I would like to use it as a translator, to other video learning but no code of the students a little welfare bar

The first is the login.jsp login interface code.

<%@ page language= "java" import= "java.util.*" pageencoding= "gb2312"%><%string path = Request.getcontextpath ( ); String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";%> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >
Then there is the code for the Welcome interface, wel.jsp
<%@ page language= "java" import= "java.util.*,java.sql.*,com.xf.model.*" pageencoding= "gb2312"%><%string Path = Request.getcontextpath (); String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";%> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >
Then is the servlet file controller, Loginclservlet.java this is processing the account password from login.jsp
/** * Function: This is a controller, to complete the authentication of the user identity, itself is not going to complete the business logic * It is mainly to call model complete processing of data * Time: June 5, 2014 12:56:46 * cutter_point */package Com.xf.controller;import com.xf.model.*;import java.io.ioexception;import Java.io.printwriter;import java.util.*; Import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;public class LoginClServlet Extends httpservlet{/** * The Doget method of the servlet. <br> * This method was called when a form have its tag VA Lue 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 (Http ServletRequest request, HttpServletResponse response) throws Servletexception, ioexception{//get account password string u= Request.getparameter ("username");//Account String P=request.getparameter ("passwd");//SecretThe code//call model validates him USERBEANCL ubc=new userbeancl (), if (Ubc.checkuser (U, p)) {System.out.println ("This is the servlet that is used to complete the validation!! ");//Legal//Jump//response.sendredirect (" wel.jsp ")/////To get the data ready before entering the wel.jsp//first display is the default first page ArrayList al= Ubc.getusersbypage (1); int pagecount=ubc.getpagecount (); Request.setattribute ("Result", AL); Request.setattribute (" PageCount ", pagecount+" "), Request.setattribute (" Pagenow "," 1 ");//But the above method is inefficient, and the efficiency is Request.getrequestdispatcher (" Wel.jsp?user= "+u). Forward (request, response);} else{//illegal//response.sendredirect ("login.jsp");//Reason ditto Request.getrequestdispatcher ("login.jsp"). Forward (Request , response);}} /** * The DoPost method of the servlet. <br> * This method was called when a form have 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 If an error occurred */public void DoPost (HTT Pservletrequest request, HttpserVletresponse response) throws Servletexception, Ioexception{this.doget (request, Response);}} 

Then there is another controller, that is, the landing into the section of the page jump Userclservlet.java
/** * Function: This controller will handle the user's paging display, the user's delete modify query, add * Time: June 5, 2014 13:47:03 * cutter_point */package Com.xf.controller;import Com.xf.model.*;import Java.io.ioexception;import Java.io.printwriter;import Java.util.arraylist;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;public class UserClServlet Extends httpservlet{/** * The Doget method of the servlet. <br> * This method was called when a form have its tag VA Lue 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 (Http ServletRequest request, HttpServletResponse response) throws Servletexception, ioexception{//get the pagenowstring s that the user wants to display _pagenow=request.getparameter ("Pagenow");//Use Userbeancl method call to get Pagenowtry{int Pagenow=integeR.parseint (S_pagenow);//Call Userbeancluserbeancl ubc=new Userbeancl ();//Prepare the data before entering wel.jsp ArrayList al= Ubc.getusersbypage (pagenow); int pagecount=ubc.getpagecount (); Request.setattribute ("Result", AL); Request.setattribute ("PageCount", pagecount+ ""); Request.setattribute ("Pagenow", pagenow+ "");// Request.setattribute ("Pagenow", Pagenow); No, it has to be quoted in the back, otherwise it won't work, because others//default bar Pagenow as a string, the result passed, thought is a string type, is actually an int type, the result is wrong System.out.println (" The paging is using the userclservlet!! "); /Jump back to wel.jsp inside to Request.getrequestdispatcher ("wel.jsp"). Forward (request, response);} catch (Exception e) {//Todo:handle exceptione.printstacktrace ();}} /** * The DoPost method of the servlet. <br> * This method was called when a form have 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 If an error occurred */public void DoPost (HTT Pservletrequest REQuest, HttpServletResponse response) throws Servletexception, Ioexception{this.doget (request, Response);}} 

Then there are three model files connected to the database, is used to be the above several calls!!
respectively: Userbean.java,userbeancl.java,conndb.java
/** * Function: This is a javabean, corresponding to the users table, representing the data * Time: June 4, 2014 10:39:33 * cutter_point  */package Com.xf.model;public class userbean{private int userid;private String username;private string passwd;private string email;private int grade;public i NT GetUserId () {return userId;} public void Setuserid (int userId) {this.userid = userId;} Public String GetUserName () {return username;} public void Setusername (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 (int grade) {This.grade = grade;}}

/** * Function: This is a processing class, also called Bo, the main package for the users table of various operations * each Userbean object into the ArrayList inside, earlier close and database link * Time: June 4, 2014 10:43:48 * cutter_point */package com.xf.model;import java.sql.*;import java.util.*;p ublic class userbeancl{private Statement sm=null;private ResultSet rs=null;private Connection ct=null;private int pagesize=3;//default starting from first page private int rowcount=0;// This query from the database private int pagecount=0;//through ROWCOUNT and pagesize to obtain public void close () {try{if (rs! = null) {rs.close (); rs=null;} if (SM! = null) {sm.close (); sm=null;} if (ct! = null) {ct.close (); ct=null;}} catch (Exception e) {//TODO auto-generated catch Blocke.printstacktrace ();}} Get PageCount, page total public int getpagecount () {try{//get link ct=new conndb (). Getconn ();//declaration, creating a Smsm=ct.createstatement ( );//4. Query the database for resultset rs=sm.executequery ("SELECT count (*) from users");//Note here must next, otherwise GG dense if (Rs.next ()) { Rowcount=rs.getint (1);} Calculates the result of the PageCount if (rowcount%pagesize = = 0) {pagecount=rowcount/pagesize;} else{pagecount=rowcount/pagesize+1;}} catch (Exception e) {//Todo:handle ExceptionE.printstacktrace ();} Finally{this.close ();} return PageCount;} Get user needs to display the information (paging) public ArrayList getusersbypage (int pagenow) {ArrayList a1=new ArrayList (); try{//get link ct=new conndb () . Getconn ();//create statementsm=ct.createstatement ();//query out the need to display the information rs=sm.executequery ("Select Top" +pagesize+ "* from The users where UserId is not in (select Top "+pagesize* (pageNow-1) +" userId from Users) "), and/or the information obtained is stored on the ArrayList (Rs.next ()) {UserBean ub=new UserBean (); Ub.setuserid (Rs.getint (1)); Ub.setusername (Rs.getstring (2)); UB.SETPASSWD ( Rs.getstring (3)); Ub.setemail (Rs.getstring (4)); Ub.setgrade (Rs.getint (5));//Put UB in ArrayList to A1.add (UB);}} catch (Exception e) {e.printstacktrace ();//Todo:handle exception}finally{//Close Resource this.close ();} return A1;} Check that the account password is correct public boolean checkUser (String u, String p) {Boolean b=false;try{//to the database to verify Ct=new conndb (). Getconn ();//3, Create a statementsm=ct.createstatement ();//4, query, put the query first result in RS rs=sm.executequery ("Select passwd from Users where Username= ' "+u+");//depending on the result to determine whether the data to be searched if (Rs.next ()) {//User name exists, verify the password if (rs.getstring (1). Equals (p)) {b=true;}}} catch (Exception e) {e.printstacktrace ();//Todo:handle Exception}finally{this.close ();} return b;}}

/** * Function: Get the database link * Time: June 4, 2014 10:47:57 * cutter_point */package com.xf.model;import java.sql.*;p ublic class Conndb{priv Ate Connection ct=null;public Connection getconn () {TRY{//1, load drive Class.forName (" Com.microsoft.sqlserver.jdbc.SQLServerDriver ");//2, Get link ct=drivermanager.getconnection (" jdbc:sqlserver:// LOCALHOST:1433;DATABASENAME=SPDB1 "," sa "," ");} catch (Exception e) {//TODO auto-generated catch Blocke.printstacktrace ();} return CT;}}


PS: Continuous efforts, silently learn!!!