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ajax簡單登錄說明

mage odin 使用 iter doctype for 新頁面 javax 不同的

ajax 簡單登錄說明:

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//依據id查找節點
function $(id){
    return document.getElementById(id);
}
//依據id查找節點,然後返回節點的value
function $F(id){
    return $(id).value;
}



//獲得ajax對象
function getXhr(){
    var xhr = null;
    if(window.XMLHttpRequest){
        //非ie
        xhr= new XMLHttpRequest();
    }else{
        xhr= new ActiveXObject("Microsoft.XMLHttp");
    }
    return xhr;
}
<%@ page 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>
<script type="text/javascript" src="js/ajax.js"></script>
<title>Insert title here</
title> <script type="text/javascript"> function check_adminCode() { //step1.獲得ajax對象 var xhr = getXhr(); //step2.發送請求 xhr.open(‘get‘,‘check_admin.do?adminCode=‘+$F(‘adminCode‘) ,true); xhr.onreadystatechange = function(){ //step4.處理服務器返回的數據 if(xhr.readyState == 4 && xhr.status == 200){ //獲得服務器返回的數據 var txt = xhr.responseText; //更新頁面 $(‘adminCode_msg‘).innerHTML = txt; } }; xhr.send(null); }
</script> </head> <body style="font-size: 30px;"> <form action="" method="post"> 賬號:<input id="adminCode" name="adminCode" onblur="check_adminCode();"/> <span id="adminCode_msg"></span> <br/> 密碼:<input type="password" name="pwd"/><br/> <input type="submit" value="確定"/> </form> </body> </html>

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 ActionServlet extends HttpServlet{
    public void service(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException{
        System.out.println("service()");
        //獲取請求資源路徑
        //http://ip:prot/ajax-day01/check.do
        String uri = req.getRequestURI();
        System.out.println("uri:"+uri);
        //分析請求資源路徑
        String action = uri.substring(uri.lastIndexOf("/"),uri.lastIndexOf("."));
        System.out.println("action:"+action);
        res.setContentType("text/html;charset=utf-8");
        PrintWriter out = res.getWriter();
        //依據分析的結果,進行不同的處理。
        if("/check_admin".equals(action)){
            String adminCode = req.getParameter("adminCode");
            System.out.println("adminCode:"+adminCode);
            if("King".equals(adminCode)){
                out.println("賬號已經存在");
            }else{
                out.println("可以使用");
            }
        }
        
        //檢查單機查看幸運數字
        if("/click".equals(action)){
            System.out.println("action:"+action);
            int num = (int)(Math.random()*10000);
            System.out.println(num);
            out.println(num);
        }
        
    }
}

ajax簡單登錄說明