JSP彩色驗證碼的執行個體代碼

最後更新：2018-12-08 來源：互聯網

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image.jsp 複製代碼代碼如下:<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*" %>
<%!
Color getRandColor(int fc,int bc){//給定範圍獲得隨機顏色
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);
}
%>
<%
//設定頁面不緩衝
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
// 在記憶體中建立圖象
int width=60, height=20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
// 擷取圖形上下文
Graphics g = image.getGraphics();
//產生隨機類
Random random = new Random();
// 設定背景色
g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);
//設定字型
g.setFont(new Font("Times New Roman",Font.PLAIN,18));
//畫邊框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 隨機產生155條幹擾線，使圖象中的認證碼不易被其它程式探測到
g.setColor(getRandColor(160,200));
for (int i=0;i<155;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);
}
// 取隨機產生的認證碼(4位元字)
String sRand="";
for (int i=0;i<4;i++){
String rand=String.valueOf(random.nextInt(10));
sRand+=rand;
// 將認證碼顯示到圖象中
g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));//調用函數出來的顏色相同，可能是因為種子太接近，所以只能直接產生
g.drawString(rand,13*i+6,16);
}
// 將認證碼存入SESSION
session.setAttribute("rand",sRand);
// 圖象生效
g.dispose();
// 輸出圖象到頁面
ImageIO.write(image, "JPEG", response.getOutputStream());
%>

a.jsp------------------------------------------------------------------------------------------------------ 複製代碼代碼如下:<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%
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>
<title>認證碼輸入頁面</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="0">
</head>
<body>
<form method=post action="check.jsp">
<table>
<tr>
<td align=left>
系統產生的認證碼：
</td>
<td>
<img border=0 src="image.jsp">
</td>
</tr>
<tr>
<td align=left>
輸入上面的認證碼：
</td>
<td>
<input type=text name=rand maxlength=4 value="">
</td>
</tr>
<tr>
<td colspan=2 align=center>
<input type=submit value="提交檢測">
</td>
</tr>
</table>
</form>
</body>
</html>

check.jsp---------------------------------------------------------------------------------------------------------------------- 複製代碼代碼如下:<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<%@ page contentType="text/html; charset=gb2312" language="java"
import="java.sql.*" errorPage=""%>
<html>
<head>
<title>認證碼驗證頁面</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="0">
</head>
<body>
<%
String rand = (String) session.getAttribute("rand");
String input = request.getParameter("rand");
%>
系統產生的認證碼為：
<%=rand%>
<br>
您輸入的認證碼為：
<%=input%>
<br>
<br>
<%
if (rand.equals(input)) {
%>
<font color=green>輸入相同，認證成功！</font>
<%
} else {
%>
<font color=red>輸入不同，認證失敗！</font>
<%
}
%>
</body>
</html>

本文章原先以中文撰寫並發佈於 aliyun.com，亦設英文版本，僅作資訊用途。本網站不對文章的準確性，完整性或可靠性或其任何翻譯作出任何明示或暗示的陳述或保證。如對該文章有任何疑慮或投訴，請傳送電郵至 info-contact@alibabacloud.com 並提供相關疑慮或投訴的詳細說明。職員會於 5 個工作天內與您聯絡，一經驗證之後，即會刪除該侵權內容。

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