<分区>
这是我在这个网站上的第一个查询。希望你们能帮助完成我的项目。提前致谢。
我粘贴了我项目的完整代码。我想要一个解决方案(即)在单击注销按钮后，用户应该导航到登录页面，当他尝试单击后退按钮时，他不应该转到上一页并且应该在同一个登录页面中。
index.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Login</title>
<style type="text/css">
.header {
width: 250px;
height: 50px;
background-color: #6495ED;
font-family: verdana;
font-size: 20px;
font-weight: bold;
}
.header2 {
width: 250px;
height: 50px;
background-color: "#FFE4B5";
font-family: verdana;
font-size: 12px;
font-weight: bold;
}
</style>
<script type="text/javascript">
<%String name = (String) request.getAttribute("status");%>
var alertMsg = "<%=name%>
";
if (alertMsg != "null" && alertMsg != '') {
alert(alertMsg);
}
</script>
<script src="<%=request.getContextPath()%>/gen_validatorv4.js"
type="text/javascript"></script>
</head>
<body>
<form name="login" action="LoginServlet" method="post">
<center>
<a href="index.jsp" class="header2" style="background-color: #FFE4B5";>Home</a>
</center>
<center>
<table
style="background-color: #CAE1FF; border-color: 1px solid red;">
<tr>
<td align="center" class="header" colspan="2">Login</td>
</tr>
<tr height="50px">
<td align="" class=""
style="padding-left: 10px; font-family: tohoma;">Username</td>
<td><input type="text" name="username" style="width: 150px;" />
</td>
</tr>
<tr height="50px">
<td align="" class=""
style="padding-left: 10px; font-family: tohoma;">Password</td>
<td><input type="password" name="password"
style="width: 150px;" /></td>
</tr>
<tr height="50px">
<td></td>
<td align="center" colspan="0">
<table style="width: 100%;">
<tr>
<td align="left"><input type="submit" name="submit"
value="Login"
style="width: 60px; height: 25px; background: #436EEE; color: white !important; border: 1px solid #0000EE;; border-radius: 2;" />
</td>
<td><input type="reset" value="Cancel"
style="width: 60px; height: 25px; background: #436EEE; color: white !important; border: 1px solid #0000EE;; border-radius: 2;" />
</td>
<td><a href="register.jsp">New User?</a></td>
</tr>
</table></td>
</tr>
</table>
</center>
</form>
<script type="text/javascript">
var formValidator = new Validator("login");
formValidator.addValidation("username", "req",
"Please enter your User Name");
formValidator.addValidation("password", "req",
"Please enter your Password");
</script>
</body>
</html>
LoginServlet.java
package pack;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
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;
/**
* Servlet implementation class LoginServlet
*/
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet implements Filter {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public LoginServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
* response)
*/
@Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
* response)
*/
@Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
String loginName = null;
String loginPass = null;
String status;
HttpSession session = request.getSession();
String username = request.getParameter("username");
String password = request.getParameter("password");
String jdbcDriver = "com.mysql.jdbc.Driver";
String dbURL = "jdbc:mysql://localhost:3306/studentdetails";
String uname = "root";
String pwd = "admin";
try {
Class.forName(jdbcDriver);
Connection con = DriverManager.getConnection(dbURL, uname, pwd);
Statement stmt = con.createStatement();
ResultSet rs;
String query = "SELECT username, password FROM registration WHERE username = '"
+ username + "' AND password = '" + password + "'";
System.out.println(query);
stmt.executeQuery(query);
boolean permission = false;
rs = stmt.getResultSet();
while (rs.next()) {
permission = true;
loginName = rs.getString("username");
loginPass = rs.getString("password");
}
System.out.println(loginName);
System.out.println(loginPass);
rs.close();
stmt.close();
if (permission == true) {
request.getSession(true);
session.setAttribute("username", loginName);
RequestDispatcher redis = request
.getRequestDispatcher("/WEB-INF/pages/list.jsp");
redis.forward(request, response);
} else {
System.out.println("Permission denied");
status = "Username not yet registered";
request.setAttribute("status", status);
RequestDispatcher redis = request
.getRequestDispatcher("index.jsp");
redis.forward(request, response);
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
@Override
public void doFilter(ServletRequest req, ServletResponse res,
FilterChain chain) throws IOException, ServletException {
// TODO Auto-generated method stub
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
HttpSession session = request.getSession(false);
if (session != null && session.isNew()) {
response.setHeader("Pragma", "no-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
chain.doFilter(request, response);
} else {
response.sendRedirect("index.jsp");
}
}
@Override
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
}
}
list.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<meta http-equiv="Pragma" content="no-cache">
<meta http-equiv="Expires" content="-1">
<meta http-equiv="CACHE-CONTROL" content="NO-CACHE">
<title>Insert title here</title>
<script type="text/javascript">
function logout() {
session.removeAttribute("username");
request.getSession().invalidate();
response.sendRedirect("index.jsp");
}
</script>
</head>
<body>
<form action="LoginServlet" name = "list">
<p><%if(session.getAttribute("username")!=null){
%>
<%session.getAttribute("username");%></p>
<%} %>
<input type="button" value = "Logout" onclick="logout();"/>
</form>
</body>
</html>
web.xml
<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
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>SessionManagement</display-name>
<servlet>
<servlet-name>Session</servlet-name>
<servlet-class>pack.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
<filter>
<filter-name>noCacheFilter</filter-name>
<filter-class>pack.LoginServlet</filter-class>
</filter>
<filter-mapping>
<filter-name>noCacheFilter</filter-name>
<url-pattern>/list.jsp</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>