JSP based on an MVC user login example (JavaBean + Servlet)

Let's look at the interactive diagram.

Example One,

Implementation of user login based on MVC (JavaBean + Servlet + JSP)

1, web.xml Configuration

<?xml version= "1.0″encoding=" utf-8″?>
<web-app version= "2.5″
Xmlns= "Http://java.sun.com/xml/ns/javaee"
Xmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance"
Xsi:schemalocation= "Http://java.sun.com/xml/ns/javaee
Http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd ">
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>

<servlet>
<servlet-name>loginServlet</servlet-name>
<servlet-class>org.zxj.mvcdemo.servlet.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>loginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
</web-app>

2, User

Package org.zxj.mvcdemo.vo;

public class user{
Private String userid;
private String name;
private String password;
public void Setuserid (String userid) {
This.userid = userid;
}
public void SetName (String name) {
THIS.name = name;
}
public void SetPassword (String password) {
This.password = password;
}
Public String GetUserID () {
return This.userid;
}
Public String GetName () {
return this.name;
}
Public String GetPassword () {
return This.password;
}

}

3, DatabaseConnection

Package ORG.ZXJ.MVCDEMO.DBC;

Import java.sql.*;

public class databaseconnection{

private static final String Dbdriver = "Com.mysql.jdbc.Driver";
private static final String Dburl = "JDBC:MYSQL://LOCALHOST:3306/ZXJ";
private static final String Dbuser = "root";
private static final String Dbpassword = "PF";
private static Connection con = null;
Public DatabaseConnection () throws exception{
try{
Class.forName (Dbdriver);
This.con = Drivermanager.getconnection (Dburl,dbuser,dbpassword);
}catch (Exception e) {
Throw e;
}
}
Public Connection getconnection () {
return This.con;
}
public void Close () throws Exception {
if (This.con!= null) {
try{
This.con.close ();
}catch (Exception e) {
Throw e;
}
}
}
}

4, Iuserdao

Package Org.zxj.mvcdemo.dao;

Import Org.zxj.mvcdemo.vo.User;

public interface iuserdao{
public boolean findlogin (user user) throws Exception;
}

5, Userdaoimpl

Package Org.zxj.mvcdemo.dao.impl;

Import Org.zxj.mvcdemo.vo.User;
Import org.zxj.mvcdemo.dao.*;
Import java.sql.*;

public class Userdaoimpl implements iuserdao{
PRIVATE Connection conn = null;
Private PreparedStatement pstmt = null;
Public Userdaoimpl (Connection conn) {
This.conn = conn;
}
public boolean findlogin (user user) throws exception{
Boolean flag = false;
String sql = "SELECT name from user where userid=?" and password =? ";
this.pstmt = this.conn.prepareStatement (sql);
This.pstmt.setString (1,user.getuserid ());
This.pstmt.setString (2,user.getpassword ());
ResultSet rs = This.pstmt.executeQuery ();
if (Rs.next ()) {
User.setname (rs.getstring ("name"));
Flag = true;
}
This.pstmt.close ();
return flag;
}
}

6, Userdaoproxy

Package org.zxj.mvcdemo.dao.proxy;

Import Org.zxj.mvcdemo.vo.User;
Import org.zxj.mvcdemo.dbc.*;
Import org.zxj.mvcdemo.dao.*;
Import org.zxj.mvcdemo.dao.impl.*;
Import java.sql.*;

public class Userdaoproxy implements iuserdao{
Private databaseconnection DBC = null;
Private Iuserdao DAO = null;
Private PreparedStatement pstmt = null;
Public Userdaoproxy () {
try{
THIS.DBC = new DatabaseConnection ();
}catch (Exception e) {
E.printstacktrace ();
}
This.dao = new Userdaoimpl (Dbc.getconnection ());
}
public boolean findlogin (user user) throws exception{
Boolean flag = false;
try{
Flag = this.dao.findLogin (user);
}catch (Exception e) {
Throw e;
}finally{
This.dbc.close ();
}
return flag;
}
}

7, Daofactory

Package org.zxj.mvcdemo.factory;

Import org.zxj.mvcdemo.dao.*;
Import org.zxj.mvcdemo.dao.proxy.*;
public class daofactory{
public static Iuserdao Getiuserdaoinstance () {
return new Userdaoproxy ();
}
}

8, Loginservlet

Package org.zxj.mvcdemo.servlet;

Import java.io.*;
Import java.util.*;
Import javax.servlet.*;
Import javax.servlet.http.*;
Import org.zxj.mvcdemo.factory.*;
Import org.zxj.mvcdemo.vo.*;

public class Loginservlet extends httpservlet{
public void Doget (HttpServletRequest req, httpservletresponse res) throws Servletexception,ioexception {
String Path = "login.jsp";
String UserID = req.getparameter ("userid");
String Userpass = Req.getparameter ("Userpass");
list<string> info = new arraylist<string> ();
if (UserID = null | | "". Equals (userid)) {
Info.add ("User ID cannot be empty");
}
if (Userpass = null | | "". Equals (Userpass)) {
Info.add ("Password cannot be blank");
}
if (info.size () = = 0) {
User user = new user ();
User.setuserid (userid);
User.setpassword (Userpass);
try{
if (Daofactory.getiuserdaoinstance (). Findlogin (user)) {
Info.add ("User login successful, welcome" +user.getname () + "login");
}else{
Info.add ("User Login failed");
}
}catch (Exception e) {
E.printstacktrace ();
}
}
Req.setattribute ("info", info);
Req.getrequestdispatcher (Path). Forward (Req,res);
RequestDispatcher rd = null;
RD = Req.getrequestdispatcher (path);
Rd.forward (Req,res);

}
public void DoPost (HttpServletRequest req, httpservletresponse res) throws Servletexception,ioexception {
Doget (Req,res);
}
}

9, login.jsp

<%@ page language= "java" contenttype= "text/html" pageencoding= "GBK"%>
<%@ page import= "java.util.*"%>
<title> Login </title>
<meta http-equiv= "Content-type" content= "TEXT/HTML;CHARSET=GBK" >

<body>
<%
Request.setcharacterencoding ("GBK");
list<string> info = (list<string>) request.getattribute ("info");
if (info!= null) {
Iterator<string> iter = Info.iterator ();
while (Iter.hasnext ()) {
Out.println (Iter.next ());
}
}
%>
<form action= "Loginservlet" method= "POST" >
User: <input type= "text" name= "userid"/> <br/>
Password: <input type= "password" name= "Userpass"/><br/>
<input type= "Submit" value= "Login"/>
<input type= "reset" value= "reset"/>
</body

Example Two,

First: JSP: the page instruction and HTML composition of the query interface query_condention.jsp, that is, we now HTML page and ASP page similar.

<%@ page language= "java" contenttype= "TEXT/HTML;CHARSET=GBK"%>
<title> Student Information </title>
<body>
<form action= "Searchstudentservlet" method= "POST" >
Date of birth: <input type= "text" name= "Begindate" > to <input type= "text" name= "EndDate" >
<input type= "Submit" value= "inquiry student" >
</form>
</body>

Second: The control layer Searchstudentservlet is used to accept the client's request to process the process, call model (Studentmanager.java), and forward to the student_list.jsp page of the backend server to be requested

Import java.text.*;
Import java.util.*;
Import java.io.*;
Import javax.servlet.http.*;
Import javax.servlet.*;

Import com.bjpowernode.exam.model.*;
Import com.bjpowernode.exam.manager.*;

public class Searchstudentservlet extends HttpServlet {

public void doget (HttpServletRequest request, httpservletresponse response)
Throws Servletexception, IOException {
DoPost (request, response);
}

public void DoPost (HttpServletRequest request, httpservletresponse response)
Throws Servletexception, IOException {

String sbegindate = Request.getparameter ("Begindate");
String senddate = Request.getparameter ("EndDate");

Date begindate = new Date ();
Date EndDate = new Date ();
try {
Begindate = new SimpleDateFormat ("Yyyy-mm-dd"). Parse (sbegindate);
EndDate = new SimpleDateFormat ("Yyyy-mm-dd"). Parse (senddate);
}catch (Exception e) {
E.printstacktrace ();
}

Studentmanager Studentmanager = new Studentmanagerimpl ();
list<student> studentlist = studentmanager.findstudentlist (begindate, EndDate);

Set the student list to the Requet range
Request.setattribute ("Student_list", studentlist);

Forwarding, forwarding is forwarded on the server side, the client is not aware of
Request.getrequestdispatcher ("/student_list.jsp"). Forward (request, response);


Put the studentlist in the session
HttpSession session = Request.getsession ();
Session.setattribute ("Student_list", studentlist);

Redirect does not share the request
The following is a wrong notation, which represents the port 8080
Response.sendredirect ("/student_list.jsp");
Response.sendredirect (Request.getcontextpath () + "/student_list.jsp");
}
}

Third: The student_list.jsp page receives the data to form the HTML, returns to the browser, renders in the interface

<%@ page language= "java" contenttype= "TEXT/HTML;CHARSET=GBK"%>
<%@ page import= "java.util.*"%>
<%@ page import= "java.text.*"%>
<%@ page import= "com.bjpowernode.exam.model.*"%>
<%@ page import= "com.bjpowernode.exam.manager.*"%>
<title> Student Information </title>
<style type= "Text/css" >
/* Table width is 1px, solid line, black */
table{
BORDER:1PX solid black;
Border-collapse:collapse;
}

TD {
BORDER:1PX solid black;
Border-collapse:collapse;
}

</style>
<body>
<table border= "1" >
<tr>
<td> Student Code </td>
<td> name </td>
<td> Sex </td>
<td> Birth date </td>
<td> Contact Tel </td>
<td> Home Address </td>
<td> class name </td>
<td> Age </td>
</tr>
<%
List<student> studentlist = (List) request.getattribute ("Student_list");
List<student> studentlist = (List) session.getattribute ("Student_list");
For (iterator<student> iter=studentlist.iterator (); Iter.hasnext ();) {
Student Student = Iter.next ();
%>
<tr>
<td><%=student.getstudentid ()%></td>
<td><%=student.getstudentname ()%></td>
<td><%=student.getsex ()%></td>
<td><%=new SimpleDateFormat ("Yyyy-mm-dd"). Format (Student.getbirthday ())%></td>
<td><%=student.getcontacttel ()%></td>
<td><%=student.getaddress ()%></td>
<td><%=student.getclasses (). Getclassesname ()%></td>
<%
Long B = 1000l*60l*60l*24l*365l;
Long a = System.currenttimemillis ()-Student.getbirthday (). GetTime ();
%>
<td><%=a/b%></td>
</tr>
<%
}
%>
</table>
</body>

The student_list.jsp page of the view is a mixture of HTML and Java code, where the query conditional interface query_condention.jsp primarily HTML, because the interaction of background data is not involved.

IV: XML configuration servlet:

<?xml version= "1.0" encoding= "iso-8859-1"
<web-app xmlns= "HTTP://JAVA.SUN.COM/XML/NS/J2EE"
    xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance"
    xsi: schemalocation= "Http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
     version= "2.4"
 <servlet>
  <servlet-name>searchstudentservlet </servlet-name>
  <servlet-class>searchstudentservlet</servlet-class>
  </servlet>
 <servlet-mapping>
  <servlet-name>searchstudentservlet</ Servlet-name>
  <url-pattern>/searchstudentservlet</url-pattern>
 </ Servlet-mapping>
 
</web-app>