標籤：param ;; html 4.01 pre 更新 判斷 lan path 提交
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP ‘regUser.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"><script type="text/javascript">var xhr;//建立Xhr對象的函數;function createXhr(){try{//普通方式;return new XMLHttpRequest();}catch(e){//異常，則另外一種方式;return new ActiveXObject("Microsoft.XMLHTTP");}}//使用者名稱，文字框失去焦點處理函數;function checkUser(){xhr=createXhr();//得到文字框中輸入的內容；var username=document.getElementById("username").value;//設定回呼函數;xhr.onreadystatechange=callback;//alert(username);//佈建要求方式和url，因為是get方式，請求資料直接在url的後面;xhr.open("get","checkUserAction?username="+username);//發送請求;xhr.send(null);}function callback(){//判斷請求完成，並且成功返回;if(xhr.readyState==4&&xhr.status==200){var msg=document.getElementById("msg");var res=xhr.responseText;//alert(res);//根據響應返回的資料，進行頁面更新;if(res=="true"){msg.innerHTML=‘使用者名稱已經存在‘;}else{msg.innerHTML=‘使用者名稱可以註冊‘;}}}</script> </head> <body><form action="regAction" method="post"> 賬戶：<input type=‘text‘ id=‘username‘ name=‘username‘ onblur=‘checkUser()‘/><span id=‘msg‘></span><br/>密碼:<input type=‘password‘ name=‘userpwd‘><br/>郵箱：<input type=‘text‘ name=‘email‘><br/>地址:<input type=‘text‘ name=‘address‘><br/><input type=‘submit‘ value=‘註冊‘/></form> </body></html>
響應的Servlet代碼:
package web;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;public class CheckUserServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {resp.setContentType("text/html;charset=utf-8");PrintWriter out=resp.getWriter();//擷取提交資料;String username=req.getParameter("username");if("admin".equals(username)){out.print("true");}else{out.print("false");}out.close();}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {this.doGet(req, resp);}}
Jsp Ajax之類比使用者註冊
Start building with 50+ products and up to 12 months usage for Elastic Compute Service
1 on 1 presale consultation
24/7 Technical Support 6 Free Tickets per Quarter Faster Response
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.
A comprehensive suite of global cloud computing services to power your business
Payment Methods We Support
