struts2实现验证码还是很方便的。struts确实给我们带来了很多的方便之处。
1：AuthCode.java是用来生成验证码图片的：
public class AuthCode { private ByteArrayInputStream input; private ByteArrayOutputStream output; private String code;// 验证码 private int codeNum;// 验证码字符数量 private int width; private int height; // 构造器 private AuthCode(int width, int height, int codeNum) { this.width = width; this.height = height; this.codeNum = codeNum; if (width < 15 * codeNum + 6) { this.width = 13 * codeNum + 6; } if (height < 20) { this.height = 20; } buildImage(); } // 以字符串形式返回验证码 public String getCode() { return code; } // 以输入流的形式返回验证图片 public ByteArrayInputStream getIamgeAsInputStream() { return input; } // 以输出流的形式返回验证图片 public ByteArrayOutputStream getImageAsOuputStream() { return output; } // 创建默认大小的验证码 public static AuthCode createInstance() { return new AuthCode(85, 20, 4); } // 创建指定大小的验证码 public static AuthCode createInstance(int width, int height, int codeNum) { return new AuthCode(width, height, codeNum); } // 生成验证码图片 private void buildImage() { 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150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 < 150; 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 String codes = "ABCDEFGHJKLMNOPQRSTUVWXYZ23456789"; String sRand = ""; for (int i = 0; i < codeNum; i++) { String rand = codes.charAt(random.nextInt(codes.length())) + ""; 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))); // 将字符串绘制到图片上 g.drawString(rand, i * (width / codeNum) + 6, (int)((height+12)/2)); } /* 验证码赋值 */ this.code = sRand; // 图象生效 g.dispose(); try { output = new ByteArrayOutputStream(); ImageOutputStream imageOut = ImageIO .createImageOutputStream(output); ImageIO.write(image, "JPEG", imageOut); imageOut.close(); input = new ByteArrayInputStream(output.toByteArray()); } catch (Exception e) { System.out.println("验证码图片产生出现错误：" + e.toString()); } } // 获取随机颜色 private 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); } }下面的是action中的调用方法：
public InputStream getInputStream(){ AuthCode code = AuthCode.createInstance(); HttpServletRequest request = ServletActionContext.getRequest(); HttpSession seesion = request.getSession(); // session.put("authCode", code.getCode()); seesion.setAttribute("authcode", code.getCode()); return code.getIamgeAsInputStream(); } public String execute(){ return "success"; }上面代码将生成的code放入session中了，这样在验证的时候就可以进行equals了。在action对应的.xml文件中得设置struts提供的stream模式来处理result
<action name="authcode" class="project.action.ImageAction" method="execute"> <result name="success" type="stream"> <param name="contentType">image/jpeg</param> </result> </action>然后还要在使用验证码图片的页面上添加链接：
<tr> <td width="13%" height="35" ><span class="login_txt">验证码</span></td> <td height="35" colspan="2" class="top_hui_text"> <input class="wenbenkuang" name="authCode" type="text" value="" maxLength="4" size="10"> <img src="authcode.action" alt="验证码" style="cursor:hand" title="看不清楚?换一张" οnclick="changeImage(this)"/> <label class="login_txt_bt">${authcode_msg }</label> </td> </tr>这样就可以显示随机验证码图片了。
当然在做登录的时候需要验证码图片，这个用struts2真是so easy啊：下面的是登录的action，因为写的比较赶，就很随便了：
public String login(){ String flag = ""; HttpServletRequest request = ServletActionContext.getRequest(); HttpSession session = request.getSession(); String code = (String) session.getAttribute("authcode"); if(authCode != null & authCode.toUpperCase().equals(code)){ if(pd.queryLogin(power.getUserName(), power.getPassword()) == true){ // session.put("power",power); power = pd.queryByName(power.getUserName()); session.setAttribute("power", power); System.out.println(pd.queryByName(power.getUserName()).getPowerset()); if((pd.queryByName(power.getUserName()).getPowerset()).equals("1111")){ flag = "admin"; System.out.println(flag); }else{ flag = "adminlimit"; System.out.println(flag); } }else{ flag = "fail"; } }else{ authcode_msg = "验证码错误"; flag = "error"; } return flag; }
相关资源：敏捷开发V1.0.pptx
