1、在項目中加入MySQL對應的JDBC的驅動jar包
LoginWeb/WebRoot/WEB-INF/lib/mysql-connector-java-3.2.0-alpha-bin.jar
配置檔案
代碼
<?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">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>LoginSvlt</servlet-name>
<servlet-class>com.qdu.sun.LoginSvlt</servlet-class>
</servlet>
<servlet-mapping>
<url-pattern>/LoginSvlt</url-pattern>
</servlet-mapping>
<filter>
<filter-name>FormFilter</filter-name>
<filter-class>com.qdu.sun.FormFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>FormFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
2、前台頁面login.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>登入</title>
<meta http-equiv="content-type" content="text/html; charset=GBK">
</head>
<script type="text/javascript">
// 驗證輸入不為空的腳本代碼
function checkForm(form) {
if(form.username.value == "") {
alert("使用者名不能為空!");
form.username.focus();
return false;
}
if(form.password.value == "") {
alert("密碼不能為空!");
form.password.focus();
return true;
</script>
<body>
請登入
<br>
<form action="LoginSvlt" method="post"
onsubmit="return checkForm(this);">
使用者名：
<input type="text" name="username">
<br>
密碼：
<input type="password" name="password">
<input type="submit" value="登入" name="submit1">
<input type="reset" value="重置" name="reset1">
</form>
</body>
</html>
3、背景處理LoginSvlt.java登入處理
package com.qdu.sun;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.sql.*;
public class LoginSvlt extends HttpServlet {
private String username;
private String password;
public LoginSvlt() {
super();
}
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
/**
* The doGet method of the servlet. <br>
*
* 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 error occurred
*/
* The doPost method of the servlet. <br>
* This method is called when a form has its tag value method equals to post.
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
username=request.getParameter("username");
password=request.getParameter("password");
//先定義變量，後使用和關閉
Connection conn = null;//聲明資料庫連接配接對象
Statement stmt = null; //聲明資料庫表達式對象
ResultSet rs = null;//聲明結果集對象
try {
// 載入Mysql的驅動字元串
Class.forName("com.mysql.jdbc.Driver");
// 擷取資料庫的連接配接
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/login", "root", "123456");
// 擷取表達式對象執行個體
stmt = conn.createStatement();
rs=stmt.executeQuery("select * from user where username='"+username+"'and password='"+password+"'");
if(rs.next())
{
HttpSession session=request.getSession(true);
session.setAttribute("username", username);
response.sendRedirect("welcome.jsp");
}
else
{
response.sendRedirect("error.jsp");
}
} catch (Exception e) {
e.printStackTrace();
}
* Initialization of the servlet. <br>
* @throws ServletException if an error occurs
public void init() throws ServletException {
}
FormFilter.java中文處理
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequestWrapper;
public class FormFilter implements Filter {
* Request.java 對 HttpServletRequestWrapper 進行擴充, 不影響原來的功能并能提供所 有的
* HttpServletRequest 接口中的功能. 它可以統一的對 Tomcat 預設設定下的中文問題進行解決而隻 需要用新的 Request
* 對象替換頁面中的 request 對象即可.
class Request extends HttpServletRequestWrapper {
public Request(HttpServletRequest request) {
super(request);
/**
* 轉換由表單讀取的資料的内碼. 從 ISO 字元轉到 GBK.
*/
public String toChi(String input) {
try {
byte[] bytes = input.getBytes("ISO8859-1");
return new String(bytes, "GBK");
} catch (Exception ex) {
return null;
* Return the HttpServletRequest holded by this object.
private HttpServletRequest getHttpServletRequest() {
return (HttpServletRequest) super.getRequest();
* 讀取參數 -- 修正了中文問題.
public String getParameter(String name) {
return toChi(getHttpServletRequest().getParameter(name));
* 讀取參數清單 - 修正了中文問題.
public String[] getParameterValues(String name) {
String values[] = getHttpServletRequest().getParameterValues(name);
if (values != null) {
for (int i = 0; i < values.length; i++) {
values[i] = toChi(values[i]);
}
return values;
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest httpreq = (HttpServletRequest) request;
if (httpreq.getMethod().equals("POST")) {
request.setCharacterEncoding("GBK");
} else {
request = new Request(httpreq);
chain.doFilter(request, response);
public void init(FilterConfig filterConfig) throws ServletException {
4、成功頁面
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<head>
<base href="<%=basePath%>">
<title>My JSP 'MyJsp.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
歡迎使用者：${sessionScope.username}<br>
</body>
本文轉自linzheng 51CTO部落格，原文連結:http://blog.51cto.com/linzheng/1080838
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