今天學習了cookie小功能,這個主要應用在登錄時,在你第一次登陸後,下次就可以自動登錄等;
首先是登錄頁面:
<%@ 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">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%//獲取用戶名和密碼cookie,判斷cookie是否爲空,爲空的情況就是第一次登錄,跳到登錄頁面,不爲空就直接跳轉到登陸後的頁面。
String name=null;
String password=null;
Cookie[] cookies=request.getCookies();
if(cookies!=null){
for(Cookie cookie:cookies){
if(cookie.getName().equals("username")){
name=cookie.getValue();
}
if(cookie.getName().equals("pwd")){
password=cookie.getValue();
}
}
if(name!=null&&password!=null){
response.sendRedirect("LoginServlet?username="+name+"&pwd="+password);
}
}
%>
<h1>歡迎來到動物園</h1>
<form action="<%=request.getContextPath()%>/LoginServlet" method="get">
<p>請輸入口令:<input type="text" name="username"></p>
<p>請輸入密碼:<input type="password" name="pwd"></p>
<p><input type="checkbox" name="box" value="ck">自動登錄</p>
<p><input type="submit" value="歡迎進入"></p>
</form>
</body>
</html>
下面是servlet
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
接收請求參數的值
String username=request.getParameter("username");
String password=request.getParameter("pwd");
if(username.equals("yyy")&&password.equals("123")) {
//如果沒有選中自動登錄,則要輸入賬號登錄,否則就會執行cookie,實現自動登錄
if(request.getParameter("box")==null) {
request.getRequestDispatcher("SearchAllServlet").forward(request, response);
}else {
Cookie name=new Cookie("username", username);
Cookie pwd=new Cookie("pwd", password);
response.addCookie(name);
response.addCookie(pwd);
name.setMaxAge(60*60);
pwd.setMaxAge(60*60);
request.getRequestDispatcher("SearchAllServlet").forward(request, response);
}
}