struts2实现图片验证码

生成图片验证码的主要工具类方法为：

 package com.yeting.fc.util;

 import java.awt.Color;

 import java.awt.Font;

 import java.awt.Graphics;

 import java.awt.image.BufferedImage;

 import java.io.ByteArrayInputStream;

 import java.io.ByteArrayOutputStream;

 import java.util.Random;

 import javax.imageio.ImageIO;

 import javax.imageio.stream.ImageOutputStream;

 public class ImageCodeUtil {

     /**

      * 生成随机验证码字符串

      *

      * @return

      */

     public static String getImageCodeStr() {

         Random random = new Random();

         String code[] = { "A", "a", "B", "b", "C", "c", "D", "d", "E", "e",

                 "F", "f", "G", "g", "H", "h", "I", "i", "J", "j", "K", "k",

                 "L", "l", "M", "m", "N", "n", "O", "o", "P", "p", "Q", "q",

                 "R", "r", "S", "s", "T", "t", "U", "u", "V", "v", "W", "w",

                 "X", "x", "Y", "y", "Z", "z", "0", "1", "2", "3", "4", "5",

                 "6", "7", "8", "9", "0", "1", "2", "3", "4", "5", "6", "7",

                 "8", "9", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9",

                 "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "0", "1",

                 "2", "3", "4", "5", "6", "7", "8", "9", "0", "1" };

         // 取随机产生的认证码(4位字符)

         StringBuffer codeStr = new StringBuffer("");

         for (int i = 0; i < 4; i++) {

             String cStr = code[random.nextInt(104)];

             codeStr.append(cStr);

         }

         return codeStr.toString();

     }

     /**

      * 生成带随机验证码的图片

      *

      * @param codeStr

      * @return

      */

     public static BufferedImage createImage(String codeStr) {

         int width = 60, height = 20;

         BufferedImage image = new BufferedImage(width, height,

                 BufferedImage.TYPE_INT_RGB);

         // 获取图形上下文

         Graphics g = image.getGraphics();

         // 生成随机类

         Random random = new Random();

         // 设定背景色

         g.setColor(getRandColor(200, 250));

         g.fillRect(0, 0, width, height);

         // 设定字体

         g.setFont(new Font("Times New Roman", Font.PLAIN, 18));

         // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到

         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);

         }

         for (int i = 0; i < codeStr.length(); i++) {

             String cStr = codeStr.charAt(i) + "";

             g.setColor(new Color(random.nextInt(125), random.nextInt(125),

                     random.nextInt(125)));

             g.setFont(new Font("", Font.PLAIN, 20 + random.nextInt(5)));

             g.drawString(cStr, 15 * i + random.nextInt(5),

                     20 - random.nextInt(5));

         }

         g.dispose();

         return image;

     }

     /**

      * 返回验证码图片的流格式

      *

      * @param codeStr

      * @return

      */

     public static ByteArrayInputStream getImageAsInputStream(String codeStr) {

         BufferedImage image = createImage(codeStr);

         return convertImageToStream(image);

     }

     private static ByteArrayInputStream convertImageToStream(BufferedImage image) {

         ByteArrayInputStream inputStream = null;

         ByteArrayOutputStream output = null;

         ImageOutputStream imageOut = null;

         try {

             output = new ByteArrayOutputStream();

             imageOut = ImageIO.createImageOutputStream(output);

             ImageIO.write(image, "JPEG", imageOut);

             inputStream = new ByteArrayInputStream(output.toByteArray());

         } catch (Exception e) {

             e.printStackTrace();

         } finally{

             try {

                 if(imageOut!=null){

                     imageOut.close();

                 }

             } catch (Exception e2) {

                 e2.printStackTrace();

             }

         }

         return inputStream;

     }

     /*

      * 给定范围获得随机颜色

      */

     private static 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);

     }

 }

Action中主要代码为：

package com.yeting.fc.action;

import java.io.ByteArrayInputStream;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

import com.yeting.fc.util.ImageCodeUtil;

public class ImageCodeAction extends ActionSupport{

    private static final long serialVersionUID = 1L;

    private ByteArrayInputStream inputStream;

    public String getImageCode() throws Exception{

        //获取图片字符串

        String codeStr = ImageCodeUtil.getImageCodeStr();

        ActionContext.getContext().getSession().put("rand",codeStr);

        //System.out.println(codeStr);

        inputStream = ImageCodeUtil.getImageAsInputStream(codeStr);

        return SUCCESS;

    }

    public void setInputStream(ByteArrayInputStream inputStream) {

        this.inputStream = inputStream;

    }

    public ByteArrayInputStream getInputStream() {

        return inputStream;

    }

}

struts.xml文件中配置如下:

 <!-- 验证码Action -->

    <action name="imageCode" class="imageCodeAction" method="getImageCode">

         <result type="stream">

             <param name="contentType">image/jpeg</param>

             <param name="inputName">inputStream</param>

         </result>

    </action>

登陆页面：主要代码。

 <!--刷新请求，更换验证码内容。-->

 <script type="text/javascript">

     function imageCode(){

         document.getElementById("imageCode").src="${pageContext.request.contextPath }/yeting/imageCode.action?st="+new Date();

     }

 </script>

 <!--验证码主要html文件-->

     验证码:<input style="width:50px;" type="text" name="imageCode"/>

           <a href="javascript:imageCode()">

                 <img style="margin-top: 5px;" id="imageCode" src="${pageContext.request.contextPath }/yeting/imageCode.action"/>

           </a>

           <a href="javascript:imageCode()"><input style="width:35px;" type="button" value="更换"/></a>