功能强大的验证码的Java类库：Patchca
jopen
10年前
Patchca是Piotr Piastucki写的一个java验证码开源库，打包成jar文件发布，patchca使用简单但功能强大。
本例实现了自定义背景，由于生成图片较小，波动太大时会导致部分文字显示不全，所以更改了滤镜属性。
效果图：
代码如下：
package com.ninemax.cul.servlet; import java.awt.Color; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.awt.image.BufferedImageOp; import java.io.IOException; import java.io.OutputStream; import java.util.ArrayList; import java.util.List; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.patchca.background.BackgroundFactory; import org.patchca.color.ColorFactory; import org.patchca.color.RandomColorFactory; import org.patchca.filter.ConfigurableFilterFactory; import org.patchca.filter.library.AbstractImageOp; import org.patchca.filter.library.WobbleImageOp; import org.patchca.font.RandomFontFactory; import org.patchca.service.Captcha; import org.patchca.service.ConfigurableCaptchaService; import org.patchca.text.renderer.BestFitTextRenderer; import org.patchca.text.renderer.TextRenderer; import org.patchca.word.RandomWordFactory; /** * 验证码生成类 * * 使用开源验证码项目patchca生成 * 依赖jar包：patchca-0.5.0.jar * 项目网址：https://code.google.com/p/patchca/ * * @author zyh * @version 1.00 2012-7-12 New */ public class ValidationCodeServlet extends HttpServlet { private static final long serialVersionUID = 5126616339795936447L; private ConfigurableCaptchaService configurableCaptchaService = null; private ColorFactory colorFactory = null; private RandomFontFactory fontFactory = null; private RandomWordFactory wordFactory = null; private TextRenderer textRenderer = null; public ValidationCodeServlet() { super(); } /** * Servlet销毁方法,负责销毁所使用资源. <br> */ public void destroy() { wordFactory = null; colorFactory = null; fontFactory = null; textRenderer = null; configurableCaptchaService = null; super.destroy(); // Just puts "destroy" string in log } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("image/png"); response.setHeader("cache", "no-cache"); HttpSession session = request.getSession(true); OutputStream outputStream = response.getOutputStream(); // 得到验证码对象,有验证码图片和验证码字符串 Captcha captcha = configurableCaptchaService.getCaptcha(); // 取得验证码字符串放入Session String validationCode = captcha.getChallenge(); session.setAttribute("validationCode", validationCode); // 取得验证码图片并输出 BufferedImage bufferedImage = captcha.getImage(); ImageIO.write(bufferedImage, "png", outputStream); outputStream.flush(); outputStream.close(); } /** * Servlet初始化方法 */ public void init() throws ServletException { configurableCaptchaService = new ConfigurableCaptchaService(); // 颜色创建工厂,使用一定范围内的随机色 colorFactory = new RandomColorFactory(); configurableCaptchaService.setColorFactory(colorFactory); // 随机字体生成器 fontFactory = new RandomFontFactory(); fontFactory.setMaxSize(32); fontFactory.setMinSize(28); configurableCaptchaService.setFontFactory(fontFactory); // 随机字符生成器,去除掉容易混淆的字母和数字,如o和0等 wordFactory = new RandomWordFactory(); wordFactory.setCharacters("abcdefghkmnpqstwxyz23456789"); wordFactory.setMaxLength(5); wordFactory.setMinLength(4); configurableCaptchaService.setWordFactory(wordFactory); // 自定义验证码图片背景 MyCustomBackgroundFactory backgroundFactory = new MyCustomBackgroundFactory(); configurableCaptchaService.setBackgroundFactory(backgroundFactory); // 图片滤镜设置 ConfigurableFilterFactory filterFactory = new ConfigurableFilterFactory(); List<BufferedImageOp> filters = new ArrayList<BufferedImageOp>(); WobbleImageOp wobbleImageOp = new WobbleImageOp(); wobbleImageOp.setEdgeMode(AbstractImageOp.EDGE_MIRROR); wobbleImageOp.setxAmplitude(2.0); wobbleImageOp.setyAmplitude(1.0); filters.add(wobbleImageOp); filterFactory.setFilters(filters); configurableCaptchaService.setFilterFactory(filterFactory); // 文字渲染器设置 textRenderer = new BestFitTextRenderer(); textRenderer.setBottomMargin(3); textRenderer.setTopMargin(3); configurableCaptchaService.setTextRenderer(textRenderer); // 验证码图片的大小 configurableCaptchaService.setWidth(82); configurableCaptchaService.setHeight(32); } /** * 自定义验证码图片背景,主要画一些噪点和干扰线 */ private class MyCustomBackgroundFactory implements BackgroundFactory { private Random random = new Random(); public void fillBackground(BufferedImage image) { Graphics graphics = image.getGraphics(); // 验证码图片的宽高 int imgWidth = image.getWidth(); int imgHeight = image.getHeight(); // 填充为白色背景 graphics.setColor(Color.WHITE); graphics.fillRect(0, 0, imgWidth, imgHeight); // 画100个噪点(颜色及位置随机) for(int i = 0; i < 100; i++) { // 随机颜色 int rInt = random.nextInt(255); int gInt = random.nextInt(255); int bInt = random.nextInt(255); graphics.setColor(new Color(rInt, gInt, bInt)); // 随机位置 int xInt = random.nextInt(imgWidth - 3); int yInt = random.nextInt(imgHeight - 2); // 随机旋转角度 int sAngleInt = random.nextInt(360); int eAngleInt = random.nextInt(360); // 随机大小 int wInt = random.nextInt(6); int hInt = random.nextInt(6); graphics.fillArc(xInt, yInt, wInt, hInt, sAngleInt, eAngleInt); // 画5条干扰线 if (i % 20 == 0) { int xInt2 = random.nextInt(imgWidth); int yInt2 = random.nextInt(imgHeight); graphics.drawLine(xInt, yInt, xInt2, yInt2); } } } } } 由于是个Servlet所以web.xml配置如下：
<servlet> <servlet-name>validationCode</servlet-name> <servlet-class>com.ninemax.cul.servlet.ValidationCodeServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>validationCode</servlet-name> <url-pattern>/validationCodeServlet.png</url-pattern> </servlet-mapping>JSP引用(部分)：
<img id="validationCode" alt="验证码图片" title="验证码图片" src="<%=path %>/validationCodeServlet.png" onclick="refreshCode(this)" /> <a id="aRecode" href="javascript:void(0);" onclick="refreshCode()">换一张</a>JS重新载入图片方法(参考)：
/** * 刷新验证码 * @param imgObj 验证码Img元素 */ function refreshCode(imgObj) { if (!imgObj) { imgObj = document.getElementById("validationCode"); } var index = imgObj.src.indexOf("?"); if(index != -1) { var url = imgObj.src.substring(0,index + 1); imgObj.src = url + Math.random(); } else { imgObj.src = imgObj.src + "?" + Math.random(); } }