关于在S2SH框架中使用servlet的验证码进行配置

在这里我通过程序的执行顺序，将所需(配置)文件写下来~~~

①首先在jsp页面有表单验证码（src="ImageRandCode"这个servlet可以看第③步）：

<tr>        <td height="35" class="login-text02">验证图片：<br /></td>        <td>        <a href="javascript:void(0);" onclick="refreshCode();return false;"><img src="ImageRandCode" id="img" width="109" height="40" title="看不清楚？单击刷新"></a></td></tr>

②在点击事件中会执行refreshCode()方法：

<SCRIPT language=JavaScript>//刷新验证码var refreshCode = function(){$("#img").attr("src","ImageRandCode?code="+Math.random());}</SCRIPT>

③请求会被struts2的配置所拦截下来进到struts.xml配置的action中：

<!-- 验证码的解决 --><action name="ImageRandCode" class="dispatchServletAction" method="myImg"><result>/ImageRandCode</result></action> 

class="dispatchServletAction"这个在spring的配置文件applicationContext.xml中配置：

<!-- 验证码管理 -->     <bean id="dispatchServletAction" class="com.student.action.DispatchServletAction"> </bean>

④接着会进到action中DispatchServletAction.java方法为Img()代码：

package com.student.action;import com.opensymphony.xwork2.ActionSupport;public class DispatchServletAction extends ActionSupport {/**  * 转发自定义的Servlet，如验证码的生成  */ private static final long serialVersionUID = 1L;  public String myImg() {  return SUCCESS; }}

然后会到第③步的<result>/ImageRandCode</result>中，这个执行会指向servlet中如下

⑤请求会去web.xml的servlet配置（声明，确定你自己已经在web.xml中配置过S2SH的struts2和spring了，在这里我就不把配置写出来了）：

<!-- 验证码 --><servlet>      <servlet-name>ImageRandCode</servlet-name>      <servlet-class>com.students.util.ImageRandCode</servlet-class></servlet><servlet-mapping>    <servlet-name>ImageRandCode</servlet-name>    <url-pattern>/ImageRandCode</url-pattern></servlet-mapping>

⑥根据servlet的请求，会去ImageRandCode.java的类中，这样验证码就显示在页面上了：

package com.students.util;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.sun.image.codec.jpeg.JPEGCodec;import com.sun.image.codec.jpeg.JPEGImageEncoder;/** * 动态生成验证码 * @author Administrator * */public class ImageRandCode extends HttpServlet {// public static final long serialVersionUID = 1L ;// PRivate static final String CONTENT_TYPE = "text/html; charset=GBK";public Color getRandColor(int fc, int bc) { // 给定范围获得随机颜色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);}// Initialize global variablespublic void init() throws ServletException {}// Process the HTTP Get requestpublic void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {// 设置页面不缓存response.setHeader("Pragma", "No-cache");response.setHeader("Cache-Control", "no-cache");response.setDateHeader("Expires", 0);// 在内存中创建图象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));// 画边框// g.setColor(new Color());// g.drawRect(0,0,width-1,height-1);// 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);}// 取随机产生的认证码(4位数字)String sRand = "";for (int i = 0; i < 4; i++) {String rand = String.valueOf(random.nextInt(10));sRand += rand;// 将认证码显示到图象中g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));// 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成g.drawString(rand, 13 * i + 6, 16);}// 将认证码存入sessionrequest.getSession().setAttribute("rand", sRand);// 图象生效g.dispose();// 输出图象到页面// ImageIO.write(image, "JPEG", response.getOutputStream());JPEGImageEncoder encode = JPEGCodec.createJPEGEncoder(response.getOutputStream());encode.encode(image);}// Clean up resourcespublic void destroy() {}}

嗯，就是这样子了。。。
转载请标明出处，原文地址：http://blog.csdn.net/cenyi2012/article/details/8277374