Servlet實現驗證碼圖片（一）

時間 2019-11-10

原文原文鏈接

Servlet實現數字字母驗證碼圖片（一）：javascript

生成驗證碼圖片主要用到了一個BufferedImage類，以下：html

一、引入jquery-1.10.2.js文件，建立verifyCode.jspjava

 1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 3 <html>
 4 <head>
 5 
 6 <title>Java驗證碼</title>
 7 </head>
 8 
 9 <body>
10     <table width="100%" border="0" cellspacing="0" cellpadding="0">
11         <tr>
12             <td width="100"></td>
13             <td width="100">驗證碼：</td>
14             <td width="150"><input id="veryCode" name="veryCode" type="text"
15                 class="yzm" value="" onmouseout="isRightCode()" /></td>
16             <td width="135"><img id="imgObj" alt="" src="${pageContext.request.contextPath}/DrawImage"
17                 onclick="changeImg()" /></td>
18             <td><a href="javascript:void(0);" onclick="changeImg()">看不清，換一張</a></td>
19             <td></td>
20         </tr>
21         <tr>
22             <td style="line-height: 38px; color: #FF0000; text-align: center;"
23                 colspan="4" id="info"></td>
24             <td></td>
25         </tr>
26     </table>
27 </body>
28 <script type="text/javascript"    src="js/jquery-1.10.2.js"></script>
29 <script type="text/javascript">
30         /** 
31          * 驗證code-js 
32          */
33 
34         // 點擊換一張驗證碼  
35         function changeImg() {
36             var imgSrc = $("#imgObj");
37             var src = imgSrc.attr("src");
38             //時間戳 ,爲了使每次生成圖片不一致，即不讓瀏覽器讀緩存，因此須要加上時間戳  
39             var timestamp = (new Date()).valueOf();
40             src =src +"?timestamp=" + timestamp;;
41             imgSrc.attr("src", src);
42             $("#info").html("");
43         }
44         // 驗證碼驗證  
45         function isRightCode() {
46             var code = $("#veryCode").val();
47             alert("code="+code);  
48             code = "c=" + code;
49             $.ajax({
50                 type : "POST",
51                 url : "resultServlet",
52                 data : code,
53                 success :function callback(data) {// 驗證之後處理提交信息或錯誤信息  
54                     if (data.toString() == 1) {
55                         $("#info").html("提示您：驗證成功了！");
56                         return;
57                     } else {
58                         $("#info").html(data);
59                         return;
60                     }
61                 }
62             });
63         }
64 </script>
65 </html>

2.建立畫圖servlet，DrawImage.javajquery

  1 package com.utils;
  2 
  3 import java.awt.Color;
  4 import java.awt.Font;
  5 import java.awt.Graphics;
  6 import java.awt.Graphics2D;
  7 import java.awt.image.BufferedImage;
  8 import java.io.IOException;
  9 import java.util.Random;
 10 
 11 import javax.imageio.ImageIO;
 12 import javax.servlet.ServletException;
 13 import javax.servlet.annotation.WebServlet;
 14 import javax.servlet.http.HttpServlet;
 15 import javax.servlet.http.HttpServletRequest;
 16 import javax.servlet.http.HttpServletResponse;
 17 
 18 /**
 19  * 生成隨機驗證碼圖片
 20  * 
 21  * @author huang
 22  * 
 23  */
 24 @WebServlet("/DrawImage")
 25 public class DrawImage extends HttpServlet {
 26     private static final long serialVersionUID = 1L;
 27     public static final int WIDTH = 120;
 28     public static final int HEIGHT = 30;
 29 
 30     // 在報java.lang.NoClassDefFoundError: Could not initialize class
 31     // javax.imageio.ImageIO錯的時候加上這個很管用。
 32     static {
 33         ImageIO.scanForPlugins();
 34     }
 35 
 36     public void doGet(HttpServletRequest request, HttpServletResponse response)
 37             throws ServletException, IOException {
 38         this.doPost(request, response);
 39     }
 40 
 41     public void doPost(HttpServletRequest request, HttpServletResponse response)
 42             throws ServletException, IOException {
 43         request.setCharacterEncoding("utf-8");
 44         response.setContentType("text/html;charset=utf-8");
 45         // 建立緩存
 46         BufferedImage bi = new BufferedImage(WIDTH, HEIGHT,
 47                 BufferedImage.TYPE_INT_RGB);
 48         // 得到畫布
 49         Graphics g = bi.getGraphics();
 50         // 設置背影色
 51         setBackGround(g);
 52         // 設置邊框
 53         setBorder(g);
 54         // 畫干擾線
 55         drawRandomLine(g);
 56         // 寫隨機數
 57         String random = drawRandomNum((Graphics2D) g);
 58         // 將隨機漢字存在session中
 59         request.getSession().setAttribute("checkcode", random);
 60         // 將圖形寫給瀏覽器
 61         response.setContentType("image/jpeg");
 62         // 發頭控制瀏覽器不要緩存
 63         response.setDateHeader("expries", -1);
 64         response.setHeader("Cache-Control", "no-cache");
 65         response.setHeader("Pragma", "no-cache");
 66         // 將圖片寫給瀏覽器
 67         ImageIO.write(bi, "jpg", response.getOutputStream());
 68     }
 69 
 70     /**
 71      * 設置背景色
 72      * 
 73      * @param g
 74      */
 75     private void setBackGround(Graphics g) {
 76         // 設置顏色
 77         g.setColor(new Color(249, 249, 249));
 78         // 填充區域
 79         g.fillRect(0, 0, WIDTH, HEIGHT);
 80 
 81     }
 82 
 83     /**
 84      * 設置邊框
 85      * 
 86      * @param g
 87      */
 88     private void setBorder(Graphics g) {
 89         // 設置邊框顏色
 90         // RGB
 91         g.setColor(new Color(210, 209, 205));
 92         // 邊框區域
 93         g.drawRect(1, 1, WIDTH - 2, HEIGHT - 2);
 94     }
 95 
 96     /**
 97      * 畫隨機線條
 98      * 
 99      * @param g
100      */
101     private void drawRandomLine(Graphics g) {
102         // 設置顏色
103         g.setColor(Color.GRAY);
104         // 設置線條個數並畫線
105         for (int i = 0; i < 5; i++) {
106             int x1 = new Random().nextInt(WIDTH);
107             int y1 = new Random().nextInt(HEIGHT);
108             int x2 = new Random().nextInt(WIDTH);
109             int y2 = new Random().nextInt(HEIGHT);
110             g.drawLine(x1, y1, x2, y2);
111         }
112     }
113 
114     /**
115      * 畫隨機漢字
116      * 
117      * @param g
118      * @return
119      */
120     private String drawRandomNum(Graphics2D g) {
121         StringBuffer sb = new StringBuffer();
122         // 設置字體
123         g.setFont(new Font("宋體", Font.BOLD, 20));
124         // 準備經常使用漢字集
125         // String base =
126         // "\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6";
127         // String base =
128         // "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6";
129         // 準備經常使用字符集
130         String base = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
131         int x = 5;
132         // 控制字數
133         for (int i = 0; i < 4; i++) {
134             // 生成0-255的隨機數
135             int R = new Random().nextInt(256);
136             int G = new Random().nextInt(256);
137             int B = new Random().nextInt(256);
138             // 設置每一個隨機數的顏色
139             g.setColor(new Color(R, G, B));
140             // 設置字體旋轉角度
141             int degree = new Random().nextInt() % 30;
142             // 截取漢字
143             String ch = base.charAt(new Random().nextInt(base.length())) + "";
144             sb.append(ch);
145             // 正向角度
146             g.rotate(degree * Math.PI / 180, x, 20);
147             g.drawString(ch, x, 20);
148             // 反向角度
149             g.rotate(-degree * Math.PI / 180, x, 20);
150             x += 30;
151         }
152         return sb.toString();
153     }
154 }

3.建立驗證結果servlet，ResultServlet.javaajax

 1 package com.utils;
 2 
 3 import java.io.IOException;  
 4 import java.io.PrintWriter;  
 5   
 6 
 7 import javax.servlet.ServletException;  
 8 import javax.servlet.annotation.WebServlet;
 9 import javax.servlet.http.HttpServlet;  
10 import javax.servlet.http.HttpServletRequest;  
11 import javax.servlet.http.HttpServletResponse;  
12   
13 /** 
14  * 結果驗證Servlet 
15  * @author huang 
16  * 
17  */  
18 @WebServlet("/resultServlet")
19 public class ResultServlet extends HttpServlet {  
20   
21     /** 
22      *  
23      */  
24     private static final long serialVersionUID = 1L;  
25   
26     public void doGet(HttpServletRequest request, HttpServletResponse response)  
27             throws ServletException, IOException {  
28   
29         doPost(request, response);  
30     }  
31   
32     /**   
33      * 後臺驗證輸入 
34      */  
35     public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
36         response.setContentType("text/html;charset=utf-8");  
37         String validateC = (String) request.getSession().getAttribute("checkcode");  
38         //從前臺傳來的用戶輸入的驗證碼  
39         String veryCode = request.getParameter("c");  
40         System.out.println("veryCode:"+veryCode);
41         PrintWriter out = response.getWriter();  
42         if (veryCode == null || "".equals(veryCode)) {  
43             out.println("請輸入驗證碼！");  
44         } else {  
45 //          if (validateC.equals(veryCode)) {  
46             // 忽略大小寫處理：
47             if (validateC.equalsIgnoreCase(veryCode)) {  
48                 out.println(1);  
49             } else {  
50                 out.println("驗證碼輸入錯誤！");  
51             }  
52         }  
53         out.flush();  
54         out.close();  
55     }  
56   
57 }