本文實(shí)例講述了jsp+ajax實(shí)現(xiàn)的局部刷新較驗(yàn)驗(yàn)證碼(onblur事件觸發(fā)較驗(yàn))。分享給大家供大家參考，具體如下：
%@ page language="java" contentType="text/html; 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>修改個(gè)人信息/title>
script>
function createXMLHttpRequest() {
//表示當(dāng)前瀏覽器不是ie,如ns,firefox
if(window.XMLHttpRequest) {
xmlHttp = new XMLHttpRequest();
} else if (window.ActiveXObject) {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
}
function validate(field) {
var div=document.getElementById("divbid");
// var reg=/[^A-Za-z0-9_]{7,10}/g;
if (field.value.length != 0) {
//創(chuàng)建XMLHttpRequest
createXMLHttpRequest();
var url = "codevalidate.jsp?authcode=" + field.value + "×tamp=" + new Date().getTime();//加時(shí)間戳防止緩存重復(fù)
xmlHttp.open("GET", url, true);
//方法地址，處理完成后自動(dòng)調(diào)用，回調(diào)
xmlHttp.onreadystatechange=function() { //匿名函數(shù)
if(xmlHttp.readyState == 4) { //Ajax引擎初始化成功
if (xmlHttp.status == 200) { //http協(xié)議成功
document.getElementById("divbid").innerHTML =xmlHttp.responseText;
}else {
alert("請(qǐng)求失敗，錯(cuò)誤碼=" + xmlHttp.status);
}
}
};
//將參數(shù)發(fā)送到Ajax引擎
xmlHttp.send(null);
}else {
div.innerHTML="div class=\"wrong\">驗(yàn)證碼不能為空/div>"
}
}
function reloadImage(imgurl){
var getimagecode=document.getElementById("codeimg");
getimagecode.src= imgurl + "?id=" + Math.random();
var code=%=session.getAttribute("code")%>;
alert(code)
}
/script>
/head>
body>
form action="authcode.jsp" method="post" name="loginform">
輸入驗(yàn)證碼：input type="text" name="authcode" id="authcode" maxlength="4" size="10" onblur="validate(this)" >span id="divbid">/span>
img id="codeimg" name="codeimg" border=0 src="authcode.jsp">
a href="javascript:reloadImage('authcode.jsp')">看不清/a>br/>
/form>
script language="javascript" type="text/javascript">
function reloadImage(imgurl){
var getimagecode=document.getElementById("codeimg");
getimagecode.src= imgurl + "?id=" + Math.random();
var code=%=session.getAttribute("code")%>;
alert(code)
}
/script>
/body>
/html>
%@ page contentType="image/JPEG"
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"
pageEncoding="GBK"%>
%!Color getRandColor(int fc, int bc) {//給定范圍獲得隨機(jī)顏色
Random random = new Random();
if (fc > 255)
fc = 255;
if (bc > 255)
bc = 255;
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}%>
%
//設(shè)置頁(yè)面不緩存
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
// 在內(nèi)存中創(chuàng)建圖象
int width = 60, height = 20;
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
// 獲取圖形上下文
Graphics g = image.getGraphics();
//生成隨機(jī)類(lèi)
Random random = new Random();
// 設(shè)定背景色
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
//設(shè)定字體
g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
//畫(huà)邊框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 隨機(jī)產(chǎn)生155條干擾線，使圖象中的認(rèn)證碼不易被其它程序探測(cè)到
g.setColor(getRandColor(160, 200));
for (int i = 0; i 100; i++) {
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x, y, x + xl, y + yl);
}
// 取隨機(jī)產(chǎn)生的認(rèn)證碼(4位數(shù)字)
String sRand = "";
for (int i = 0; i 4; i++) {
String rand = String.valueOf(random.nextInt(10));
sRand += rand;
// 將認(rèn)證碼顯示到圖象中
g.setColor(new Color(20 + random.nextInt(110), 20 + random
.nextInt(110), 20 + random.nextInt(110)));//調(diào)用函數(shù)出來(lái)的顏色相同，可能是因?yàn)榉N子太接近，所以只能直接生成
g.drawString(rand, 13 * i + 6, 16);
System.out.println(rand);
}
// 將認(rèn)證碼存入SESSION
session.setAttribute("code", sRand);
// 圖象生效
g.dispose();
// 輸出圖象到頁(yè)面
ImageIO.write(image, "JPEG", response.getOutputStream());
%>
%@ page language="java" import="java.util.*,java.util.*,java.text.*,com.neusoft.xkxt.dao.*,com.neusoft.xkxt.bean.*,com.neusoft.xkxt.util.*" pageEncoding="UTF-8"%>
%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
%
String authcode=request.getParameter("authcode");
String code=(String)session.getAttribute("code");
if(authcode.equals(code)){
out.println("div class='right'>√/div>");}
else{
out.println("div class='wrong'>驗(yàn)證碼不正確/div>");}
%>
