JSP登入頁面包括驗證碼的驗證
阿新 • • 發佈：2019-01-26
login.jsp，程式碼如下：
- <%@ 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 'login.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">
- <!--
- <link rel="stylesheet" type="text/css" href="styles.css">
- -->
- </head>
- <%
-
String incode = (String)request.getParameter("code");
- String rightcode = (String)session.getAttribute("rCode");
- if(incode != null && rightcode != null){
- if(incode.equals(rightcode)){
- out.println("驗證碼輸入正確！");
- }else{
- out.println("驗證碼輸入不正確，請重新輸入！");
- }
- }
- %>
- <body>
- <form action="login.jsp" method="post">
- 使用者名稱：
- <input type="text" name="username"/><br/>
- 密碼：
- <input type="password" name="password"/><br/>
- 驗證碼：
- <img src="number.jsp"/>
- <input type="text" name="code"/>
- <input type="submit" value="登入"/>
- </form>
- </body>
- </html>
number.jsp提供了驗證碼的提取功能，如下：
[plain] view plain copy print?
- <%@ page contentType="image/jpeg" language="java" import="java.util.*,java.awt.*,java.awt.image.*,javax.imageio.*" pageEncoding="utf-8"%>
- <%!
- Color getRandColor(int fc,int bc){
- 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);
- }
- %>
- <%
- //設定頁面不快取
- response.setHeader("Pragma","no-cache");
- response.setHeader("Cache-Control","no-catch");
- response.setDateHeader("Expires",0);
- //在記憶體中建立圖象
- int width = 60;
- int height = 20;
- BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
- //建立圖象
- Graphics g = image.getGraphics();
- //生成隨機物件
- 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("Tines Nev Roman",Font.PLAIN,18));
- //隨機產生干擾線
- g.setColor(getRandColor(160,200));
- for(int i = 0; i < 255; i++){
- int x = random.nextInt(width);
- int y = random.nextInt(height);
- int xl = random.nextInt(12);
- int yl = random.nextInt(12);
- }
- //隨機產生認證碼,4位數字
- 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)));
- g.drawString(rand,13*i+6,16);
- }
- session.setAttribute("rCode",sRand);
- //影象生效
- g.dispose();
- //輸出影象到頁面
- ImageIO.write(image,"JPEG",response.getOutputStream());
- out.clear();
- out = pageContext.pushBody();
- %>
