Java基于springMVC的验证码案例

```  2 Java验证码案例（基于springMVC方式）  3 
验证码工具类  5 package com.ekyb.common.util;  6 
import java.awt.Color;  8 import java.awt.Font;  9 import java.awt.Graphics;  10 
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 
import javax.servlet.http.HttpServletRequest;  18 
import org.springframework.beans.factory.annotation.Value;  20 import org.springframework.stereotype.Component;  21 
/**
 * 图片验证码生成类  24  *  25  * @author gx  26  */
@Component("imageCode")  28 public class ImageCode {  29     /*
 * 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      */
    @Value("${ImageCode.width}")  35     private int width;  36 
    @Value("${ImageCode.height}")  38     private int height;  39 
    @Value("${ImageCode.codeLength}")  41     private int codeLength;  42 
    @Value("${ImageCode.randomString}")  44     private String randomString;  45 
    @Value("${ImageCode.sessionKey}")  47     private String sessionKey;  48 
    @Value("${ImageCode.font.name}")  50     private String fontName;  51 
    @Value("${ImageCode.font.style}")  53     private int fontStyle;  54 
    @Value("${ImageCode.font.size}")  56     private int fontSize;  57 
    public BufferedImage getImage(HttpServletRequest request) {  59         // 在内存中创建图片
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);  61         // 获取图片上下文
        Graphics g = image.getGraphics();  63         // 生成随机类
        Random random = new Random();  65         // 设定背景颜色
        g.setColor(getRandColor(100, 250));  67         g.fillRect(0, 0, width, height);  68         // 设定字体
        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
        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);
 request.getSession().setAttribute(sessionKey, sRand);  89         request.setAttribute("sRand", sRand);  90  g.dispose();  91         return image;  92  }  93 
    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 
    // 给定范围获取随机颜色
    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 
 } 121 
    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 
    public int getWidth() { 134         return width; 135  } 136 
    public void setWidth(int width) { 138         this.width = width; 139  } 140 
    public int getHeight() { 142         return height; 143  } 144 
    public void setHeight(int height) { 146         this.height = height; 147  } 148 
    public int getCodeLength() { 150         return codeLength; 151  } 152 
    public void setCodeLength(int codeLength) { 154         this.codeLength = codeLength; 155  } 156 
    public String getRandomString() { 158         return randomString; 159  } 160 
    public void setRandomString(String randomString) { 162         this.randomString = randomString; 163  } 164 
    public String getSessionKey() { 166         return sessionKey; 167  } 168 
    public void setSessionKey(String sessionKey) { 170         this.sessionKey = sessionKey; 171  } 172 
    public String getFontName() { 174         return fontName; 175  } 176 
    public void setFontName(String fontName) { 178         this.fontName = fontName; 179  } 180 
    public int getFontStyle() { 182         return fontStyle; 183  } 184 
    public void setFontStyle(int fontStyle) { 186         this.fontStyle = fontStyle; 187  } 188 
    public int getFontSize() { 190         return fontSize; 191  } 192 
    public void setFontSize(int fontSize) { 194         this.fontSize = fontSize; 195  } 196 
} 198 
-----------------------------------------------
读取config.properties配置的验证码和图片设置 201 
#ImageCode生成器配置 203 ImageCode.width=120  
ImageCode.height=38  
ImageCode.codeLength=4  
ImageCode.randomString=ABCDEFGHIJKLMNPQRSTUVWXYZ1234567890abcdefghijkmnpqrstuvwxyz 207 ImageCode.sessionKey=SESSIONCODE 208 ImageCode.font.name=Times New Roman 209 ImageCode.font.style=0  
ImageCode.font.size=18 
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springMVC action中的代码 213 package com.ekyb.common.auContract.action; 214 
import java.io.IOException; 216 
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 
import org.springframework.stereotype.Controller; 224 import org.springframework.web.bind.annotation.RequestMapping; 225 
import com.ekyb.common.util.ImageCode; 227 
@Controller 229 @RequestMapping(value="/yanZhen") 230 public class YanZhenMaAction { 231     /*
 * @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      */
 @Resource 239  ImageCode imageCode; 240     
    private static String sRand; 242 
    @RequestMapping(value = "/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
            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
                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
                return "error"; 256  } 257  } 258  } 259 
    @RequestMapping(value = "/getImage") 261     public void getImage(HttpServletRequest request, HttpServletResponse response 262             ) throws IOException { 263         // 禁止图片缓存
        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
        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     
 } 276 } 277 -------------------------------------------------
前端登录页面代码 279 <%@ page language="java" pageEncoding="utf-8"%>
<%
    String path = request.getContextPath(); 282     String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; 283 %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>登录</title>
</head>
<script type="text/javascript" src="js/jquery-easyui/jquery.min.js"></script>
<body>
    <!-- cursor: pointer;鼠标放上显示手;   title:鼠标放上时显示的文字 -->
    <img id="imageCode" alt="" src="" onclick="checkcode()" style="cursor: pointer;" title="点我更换验证码" />
    <br>
    <form action="<%=basePath%>yanZhen/openLoginPage" method="post">
        <input type="text" value="" name="msg">
        <input type="submit" value="提交">
    </form>
</body>
<script type="text/javascript">
    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
                $("#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
        XMLHttp.open("GET", basePath + "/yanZhen/getImage?" + new Date(), true); 321         XMLHttp.send(null); 322  } 323 </script>
</html>
-----------------------------------------------------
登录成页面ok.jsp 327 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
    String path = request.getContextPath(); 330     String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() 331             + path + "/"; 332 %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>验证通过</title>
</head>
<body>
    <h2>验证通过</h2>
</body>
</html>
-------------------------------------------------
登录失败页面error.jsp 347 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
    String path = request.getContextPath(); 350     String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() 351             + path + "/"; 352 %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>验证失败</title>
</head>

<body>
    <h2>验证失败</h2>
</body>
</html>
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==****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
```