1 ```
  2 Java验证码案例（基于springMVC方式）
  3 
  4 验证码工具类
  5 package com.ekyb.common.util;
  6 
  7 import java.awt.Color;
  8 import java.awt.Font;
  9 import java.awt.Graphics;
 10 
 11 import java.awt.image.BufferedImage;
 12 import java.util.ArrayList;
 13 import java.util.Arrays;
 14 import java.util.List;
 15 import java.util.Random;
 16 
 17 import javax.servlet.http.HttpServletRequest;
 18 
 19 import org.springframework.beans.factory.annotation.Value;
 20 import org.springframework.stereotype.Component;
 21 
 22 /**
 23  * 图片验证码生成类
 24  * 
 25  * @author gx
 26  */
 27 @Component("imageCode")
 28 public class ImageCode {
 29     /*
 30      * Spring 3支持@value注解的方式获取properties文件中的配置值，大简化了读取配置文件的代码。
 31      * 在applicationContext.xml文件中配置properties文件,在bean中使用@value注解获取配置文件的值
 32      * 即使给变量赋了初值也会以配置文件的值为准。
 33      */
 34     @Value("${ImageCode.width}")
 35     private int width;
 36 
 37     @Value("${ImageCode.height}")
 38     private int height;
 39 
 40     @Value("${ImageCode.codeLength}")
 41     private int codeLength;
 42 
 43     @Value("${ImageCode.randomString}")
 44     private String randomString;
 45 
 46     @Value("${ImageCode.sessionKey}")
 47     private String sessionKey;
 48 
 49     @Value("${ImageCode.font.name}")
 50     private String fontName;
 51 
 52     @Value("${ImageCode.font.style}")
 53     private int fontStyle;
 54 
 55     @Value("${ImageCode.font.size}")
 56     private int fontSize;
 57 
 58     public BufferedImage getImage(HttpServletRequest request) {
 59         // 在内存中创建图片
 60         BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
 61         // 获取图片上下文
 62         Graphics g = image.getGraphics();
 63         // 生成随机类
 64         Random random = new Random();
 65         // 设定背景颜色
 66         g.setColor(getRandColor(100, 250));
 67         g.fillRect(0, 0, width, height);
 68         // 设定字体
 69         g.setFont(new Font(fontName, fontStyle, fontSize));
 70         g.setColor(getRandColor(160, 200));
 71         for (int i = 0; i < 155; i++) {
 72             int x = random.nextInt(width);
 73             int y = random.nextInt(height);
 74             int xl = random.nextInt(12);
 75             int yl = random.nextInt(12);
 76             g.drawLine(x, y, xl, y + yl);
 77         }
 78         // 取随机产生的认证码
 79         String sRand = randomRand(codeLength);
 80         int strWidth = width / 2 - g.getFontMetrics().stringWidth(sRand) / codeLength - fontSize;
 81         int strHeight = height / 2 + g.getFontMetrics().getHeight() / 4;
 82         for (int i = 0; i < codeLength; i++) {
 83             String rand = sRand.substring(i, i + 1);
 84             g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
 85             g.drawString(rand, 13 * i + 6 + strWidth, strHeight);
 86         }
 87         //System.out.println(sRand);
 88         request.getSession().setAttribute(sessionKey, sRand);
 89         request.setAttribute("sRand", sRand);
 90         g.dispose();
 91         return image;
 92     }
 93 
 94     public static String randomResult(int length) {
 95         String[] i = { "1", "2", "3", "4", "5", "6", "7", "8", "9", "0" };
 96         List<String> l = new ArrayList<String>();
 97         l.addAll(Arrays.asList(i));
 98         Random ran = new Random();
 99         String s = "";
100         while (l.size() > 10 - length)
101             s += l.remove(ran.nextInt(l.size()));
102         s = s.replaceAll("^(0)(\\d)", "$2$1");
103         return s;
104     }
105 
106     // 给定范围获取随机颜色
107     public Color getRandColor(int fc, int bc) {
108         Random random = new Random();
109         if(fc > 255) {
110             fc = 255;
111         }
112         if(bc > 255) {
113             bc = 255;
114         }
115         int r = fc + random.nextInt(bc - fc);
116         int g = fc + random.nextInt(bc - fc);
117         int b = fc + random.nextInt(bc - fc);
118         return new Color(r, g, b);
119 
120     }
121 
122     private String randomRand(int n) {
123         String rand = "";
124         int len = randomString.length() - 1;
125         double r;
126         for (int i = 0; i < n; i++) {
127             r = ((Math.random())) * len;
128             rand = rand + randomString.charAt((int) r);
129         }
130         return rand;
131     }
132 
133     public int getWidth() {
134         return width;
135     }
136 
137     public void setWidth(int width) {
138         this.width = width;
139     }
140 
141     public int getHeight() {
142         return height;
143     }
144 
145     public void setHeight(int height) {
146         this.height = height;
147     }
148 
149     public int getCodeLength() {
150         return codeLength;
151     }
152 
153     public void setCodeLength(int codeLength) {
154         this.codeLength = codeLength;
155     }
156 
157     public String getRandomString() {
158         return randomString;
159     }
160 
161     public void setRandomString(String randomString) {
162         this.randomString = randomString;
163     }
164 
165     public String getSessionKey() {
166         return sessionKey;
167     }
168 
169     public void setSessionKey(String sessionKey) {
170         this.sessionKey = sessionKey;
171     }
172 
173     public String getFontName() {
174         return fontName;
175     }
176 
177     public void setFontName(String fontName) {
178         this.fontName = fontName;
179     }
180 
181     public int getFontStyle() {
182         return fontStyle;
183     }
184 
185     public void setFontStyle(int fontStyle) {
186         this.fontStyle = fontStyle;
187     }
188 
189     public int getFontSize() {
190         return fontSize;
191     }
192 
193     public void setFontSize(int fontSize) {
194         this.fontSize = fontSize;
195     }
196 
197 }
198 
199 -----------------------------------------------
200 读取config.properties配置的验证码和图片设置
201 
202 #ImageCode生成器配置  
203 ImageCode.width=120  
204 ImageCode.height=38  
205 ImageCode.codeLength=4  
206 ImageCode.randomString=ABCDEFGHIJKLMNPQRSTUVWXYZ1234567890abcdefghijkmnpqrstuvwxyz  
207 ImageCode.sessionKey=SESSIONCODE  
208 ImageCode.font.name=Times New Roman  
209 ImageCode.font.style=0  
210 ImageCode.font.size=18 
211 -------------------------------------------------
212 springMVC action中的代码
213 package com.ekyb.common.auContract.action;
214 
215 import java.io.IOException;
216 
217 import javax.annotation.Resource;
218 import javax.imageio.ImageIO;
219 import javax.servlet.ServletOutputStream;
220 import javax.servlet.http.HttpServletRequest;
221 import javax.servlet.http.HttpServletResponse;
222 
223 import org.springframework.stereotype.Controller;
224 import org.springframework.web.bind.annotation.RequestMapping;
225 
226 import com.ekyb.common.util.ImageCode;
227 
228 @Controller
229 @RequestMapping(value="http://www.mamicode.com/yanZhen")
230 public class YanZhenMaAction {
231     /*
232      * @Resource默认按 byName 自动注入,是J2EE提供的， 需导入Package: javax.annotation.Resource;
233      * 
234      * @Resource有两个中重要的属性：name和type ，而Spring将@Resource注解的name属性解析为bean的
235      * 名字，而type属性则解析为bean的类型。所以如果使用name属性，则使用byName的自动注入策略，而使用 type属性时则使用
236      * byType自动注入策略。如果既不指定name也不指定type属性，这时将通过反射机制使用by Name自动注入策略。
237      */
238     @Resource
239     ImageCode imageCode;
240     
241     private static String sRand;
242 
243     @RequestMapping(value = "http://www.mamicode.com/openLoginPage")
244     public String openLoginPage(HttpServletRequest request, HttpServletResponse response) {
245         String msg=request.getParameter("msg");
246         if(msg==null&& msg.isEmpty()){
247             //得到用户读入框信息，如果没有输入或者为空，直接跳转到验证失败页面
248             return "error";
249         }else{
250             if(sRand.equalsIgnoreCase((msg))){
251                 //得到用户输入的验证码匹配成功，跳转到验证通过页面
252                 return "ok";
253             }else{
254                 //得到用户输入的验证码匹配失败，跳转到验证失败页面
255                 return "error";
256             }
257         }
258     }
259 
260     @RequestMapping(value = "http://www.mamicode.com/getImage")
261     public void getImage(HttpServletRequest request, HttpServletResponse response
262             ) throws IOException {
263         // 禁止图片缓存
264         response.setHeader("Pragma", "no-cache");
265         response.setHeader("Cache-Control", "no-cache");
266         response.setDateHeader("Expires", 0);
267         response.setContentType("image/jpeg");
268         // 将图像输出到servlet输出流中
269         ServletOutputStream sos = response.getOutputStream();
270         ImageIO.write(imageCode.getImage(request), "jpeg", sos);
271         sos.close();
272         sRand=(String)request.getAttribute("sRand");
273         String result="ok";
274     
275     }
276 }
277 -------------------------------------------------
278 前端登录页面代码
279 <%@ page language="java" pageEncoding="utf-8"%>
280 <%
281     String path = request.getContextPath();
282     String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
283 %>
284 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
285 <html>
286 <head>
287 <base href="http://www.mamicode.com/">
288 <title>登录</title>
289 </head>
290 <script type="text/javascript" src="http://www.mamicode.com/js/jquery-easyui/jquery.min.js"></script>
291 <body>
292     <!-- cursor: pointer;鼠标放上显示手;   title:鼠标放上时显示的文字 -->
293     <img id="imageCode"  src="" onclick="checkcode()" style="cursor: pointer;" title="点我更换验证码" />
294     <br>
295     <form action="<%=basePath%>yanZhen/openLoginPage" method="post">
296         <input type="text" value="" name="msg">
297         <input type="submit" value="http://www.mamicode.com/提交">
298     </form>
299 </body>
300 <script type="text/javascript">
301     var basePath = "<%=basePath%>";
302     $(function() {
303         checkcode();
304     });
305     function checkcode() {
306         var XMLHttp = null;
307         if (window.XMLHttpRequest) {
308             XMLHttp = new XMLHttpRequest();
309         } else if (window.ActiveXObject) {
310             XMLHttp = new ActiveXObject("Microsoft.XMLHTTP");
311         }
312         XMLHttp.onreadystatechange = function() {
313             if (XMLHttp.readyState == 4) {
314                 //改变验证码图片
315                 $("#imageCode").attr("src",(basePath + "/yanZhen/getImage?" + new Date()));
316             }
317         };
318         //将请求发送出去
319         //加上 new Date()防止浏览器缓存，不重新发送请求
320         XMLHttp.open("GET", basePath + "/yanZhen/getImage?" + new Date(), true);
321         XMLHttp.send(null);
322     }
323 </script>
324 </html>
325 -----------------------------------------------------
326 登录成页面ok.jsp
327 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
328 <%
329     String path = request.getContextPath();
330     String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort()
331             + path + "/";
332 %>
333 
334 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
335 <html>
336 <head>
337 <base href="http://www.mamicode.com/">
338 
339 <title>验证通过</title>
340 </head>
341 <body>
342     <h2>验证通过</h2>
343 </body>
344 </html>
345 -------------------------------------------------
346 登录失败页面error.jsp
347 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
348 <%
349     String path = request.getContextPath();
350     String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort()
351             + path + "/";
352 %>
353 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
354 <html>
355 <head>
356 <base href="http://www.mamicode.com/">
357 
358 <title>验证失败</title>
359 </head>
360 
361 <body>
362     <h2>验证失败</h2>
363 </body>
364 </html>
365 --------------------
366 ==****注意个别路径根据自己的文件路劲更改==
如果有误请多指教
367 ```