Java Jsp+servlet+mysql Implementation Login Web Design

The following files are involved:

1, login page login.jsp

2, successful jump page success.jsp

3, failed jump page fail.jsp

4,servlet Processing Class Logintestservlet.java

5, config file Web. xml

---------------------------------------------look at the code in turn--------------------------------------------

Logintestservlet.java Content

Package Com.test;import Java.io.ioexception;import Java.sql.drivermanager;import java.sql.resultset;import Javax.servlet.servletexception;import Javax.servlet.annotation.webservlet;import Javax.servlet.http.HttpServlet; Import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;import Javax.servlet.http.httpsession;import Com.mysql.jdbc.connection;import com.mysql.jdbc.statement;/** * servlet Implementation class Logintestservlet */@WebServlet ("/logintestservlet") public class Logintestservlet extends           HttpServlet {private static final long serialversionuid = 1L;            /** * @see httpservlet#httpservlet () */public Logintestservlet () {super (); }/** * @see Httpservlet#doget (httpservletrequest request, httpservletresponse response) */protected void Doget ( HttpServletRequest request, HttpServletResponse response) throws Servletexception, IOException {doPost (Request, Response);} /** * @see Httpservlet#dopost (HttpServletRequest reQuest, httpservletresponse response) */protected void DoPost (HttpServletRequest request, httpservletresponse response) Throws Servletexception, IOException {response.setcontenttype ("text/heml;charset=gb2312"); Request.setcharacterencoding ("gb2312"); String result = ""; String username = request.getparameter ("username"); String PSW = request.getparameter ("password"); if (username = = "" | | Username = = NULL | | Username.length () >20) {try {result = "Please enter a user name (cannot exceed 20 characters)"; Request.setattribute ("message", result); Response.sendredirect ("login.jsp"); return;} catch (Exception e) {e.printstacktrace ();}} if (PSW = = "" | | PSW = = NULL | | Psw.length () >) {try {result = "Please enter a password (cannot exceed 20 characters)"; Request.setattribute ("message", result); Response.sendredirect ("login.jsp"); return;} catch (Exception e) {e.printstacktrace ();}} Enlist the JDBC driver try {class.forname ("Com.mysql.jdbc.Driver"),} catch (Exception e) {System.out.print ("Class not Found Exception ");} Link urlstring url = "Jdbc:mysql://localhost:3306/demo"; Connection Conn = NULL; Statement stmt = null; ResultSet rs = null;try {conn = (Connection) drivermanager.getconnection (URL, "root", "root"); stmt = (Statement) Conn.createstatement (); String sql = "SELECT * from UserInfo where username= '" +username+ "' and userpsw= '" +psw+ "'"; rs = stmt.executequery (sql);} catch (Exception e) {e.printstacktrace ();}    HttpSession session = Request.getsession (); Session.setattribute ("username", username); try {if (Rs.next ()) {    Session.setattribute ("Age", rs.getstring ("Age"));    Session.setattribute ("Sex", rs.getstring ("Sex"));    Session.setattribute ("Weight", rs.getstring ("weight"));    Response.sendredirect ("success.jsp"); return;} else{session.setattribute ("message", "User name or password does not match.")    ");    Response.sendredirect ("fail.jsp"); return;}} catch (Exception e) {e.printstacktrace ();}}}

login.jsp Content

<%@ page language= "java" contenttype= "text/html; Charset=utf-8 "pageencoding=" UTF-8 "%><! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >
success.jsp Content
<%@ page language= "java" contenttype= "text/html; Charset=utf-8 "pageencoding=" UTF-8 "%><! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >
fail.jsp Content
<%@ page language= "java" contenttype= "text/html; Charset=utf-8 "pageencoding=" UTF-8 "%><! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >

-------------------------------------------------------Configuration Database------------------------------------------------------
The MySQL database needs to create a database demo, where the CREATE TABLE UserInfo table statement is:
CREATE Databasedemo;
Use demo
CREATE TABLE userInfo (ID int not NULL primary key,username char (a) not NULL,USERPSW char (a), age int, weight int, Sex enum (' M ', ' F '));
  
need to place the MySQL-connected jar package in the project's Lib directory
---------------------------------------------Gorgeous split-line----------------------------------------

Last web. XML content
<?xml Version= "1.0" encoding= "UTF-8"? ><web-app xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance" xmlns= "http ://java.sun.com/xml/ns/javaee "xsi:schemalocation=" Http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/ Javaee/web-app_3_0.xsd "id=" webapp_id "version=" 3.0 "><display-name>webDemo</display-name>< welcome-file-list><welcome-file>index.html</welcome-file><welcome-file>index.htm</ welcome-file><welcome-file>index.jsp</welcome-file><welcome-file>default.html</ welcome-file><welcome-file>default.htm</welcome-file><welcome-file>default.jsp</ Welcome-file></welcome-file-list> 
<servlet><servlet-name>LoginTestServlet</servlet-name><servlet-class> Com.test.logintestservlet</servlet-class></servlet><servlet-mapping><servlet-name> logintestservlet</servlet-name><url-pattern>/logintestservlet</url-pattern></ Servlet-mapping></web-app>


Java Jsp+servlet+mysql Implementation Login Web Design