【java提高】---patchca生成验证码

2023-07-18 12:05:34

Java使用patchca生成验证码

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();  

            // 填充为灰色背景

            graphics.setColor(Color.GRAY);

            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();

    }

}

本文是转载，同时自己亲自测试可行，上面的验证码截图就是实际效果参考链接：http://blog.csdn.net/zhyh1986/article/details/7741244

同时需要patchca架包：http://download.csdn.net/download/caoniquanjiaariniday/7607495

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Java使用patchca生成验证码

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