java 验证码生成
验证码效果图
import java.awt.Color; import java.awt.Font; import java.io.IOException; import java.io.OutputStream; import java.util.ArrayList; import java.util.List; import javax.imageio.ImageIO; import javax.servlet.Servlet; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.lang.math.RandomUtils; import nl.captcha.Captcha; import nl.captcha.Captcha.Builder; import nl.captcha.gimpy.BlockGimpyRenderer; import nl.captcha.text.producer.ChineseTextProducer; import nl.captcha.text.producer.DefaultTextProducer; import nl.captcha.text.renderer.DefaultWordRenderer; import nl.captcha.text.renderer.WordRenderer; public class CaptchaServlet extends HttpServlet implements Servlet { private static final long serialVersionUID = 1L; private static final String PARAM_HEIGHT = "height"; // 高度 默认为50 private static final String PARAM_WIDTH = "width";// 宽度 默认为200 private static final String PAEAM_NOISE = "noise";// 干扰线条 默认是没有干扰线条 private static final String PAEAM_TEXT = "text";// 文本 protected int _width = 150; protected int _height = 40; protected boolean _noise = false; protected String _text = "number:1,word:1,number:1,number:1,word:1"; /** * 初始化过滤器.将配置文件的参数文件赋值 * * @throws ServletException */ @Override public void init() throws ServletException { if (getInitParameter(PARAM_HEIGHT) != null) { _height = Integer.valueOf(getInitParameter(PARAM_HEIGHT)); } if (getInitParameter(PARAM_WIDTH) != null) { _width = Integer.valueOf(getInitParameter(PARAM_WIDTH)); } if (getInitParameter(PAEAM_NOISE) != null) { _noise = Boolean.valueOf(getInitParameter(PAEAM_NOISE)); } if (getInitParameter(PAEAM_NOISE) != null) { _text = String.valueOf(getInitParameter(PAEAM_TEXT)); } } /** * 因为获取图片只会有get方法 */ @Override public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { Builder builder = new Captcha.Builder(_width, _height); // 增加边框 // builder.addBorder(); // 是否增加干扰线条 if (_noise == true) { builder.addNoise(); } // ----------------自定义字体大小----------- // 自定义设置字体颜色和大小 最简单的效果 多种字体随机显示 List<Font> fontList = new ArrayList<Font>(); fontList.add(new Font("微软 雅黑", Font.LAYOUT_NO_START_CONTEXT, 30));// 可以设置斜体之类的 DefaultWordRenderer dwr = new DefaultWordRenderer(getRandomColor(), fontList); // 加入多种颜色后会随机显示 字体空心 WordRenderer wr = dwr; // 增加文本，默认为5个随机字符. if (_text == null) { builder.addText(); } else { String[] ts = _text.split(","); for (int i = 0; i < ts.length; i++) { String[] ts1 = ts[i].split(":"); if ("chinese".equals(ts1[0])) { builder.addText(new ChineseTextProducer(Integer.parseInt(ts1[1])), wr); } else if ("number".equals(ts1[0])) { // 这里没有0和1是为了避免歧义 和字母I和O char[] numberChar = new char[] { '2', '3', '4', '5', '6', '7', '8' }; builder.addText(new DefaultTextProducer(Integer.parseInt(ts1[1]), numberChar), wr); } else if ("word".equals(ts1[0])) { // 原理同上 char[] numberChar = new char[] { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'k', 'm', 'n', 'p', 'r', 'w', 'x', 'y' }; builder.addText(new DefaultTextProducer(Integer.parseInt(ts1[1]), numberChar), wr); } else { builder.addText(new DefaultTextProducer(Integer.parseInt(ts1[1])), wr); } } } // --------------添加背景------------- // 设置背景渐进效果 以及颜色 form为开始颜色，to为结束颜色 // GradiatedBackgroundProducer gbp=new GradiatedBackgroundProducer(); // gbp.setFromColor(Color.yellow); // gbp.setToColor(Color.red); // 无渐进效果，只是填充背景颜色 // FlatColorBackgroundProducer fbp=new // FlatColorBackgroundProducer(Color.red); // 加入网纹--一般不会用 // SquigglesBackgroundProducer sbp=new SquigglesBackgroundProducer(); // 没发现有什么用,可能就是默认的 // TransparentBackgroundProducer tbp = new // TransparentBackgroundProducer(); // builder.addBackground(gbp); // ---------装饰字体--------------- // 字体边框齿轮效果 默认是3 builder.gimp(new BlockGimpyRenderer(1)); // 波纹渲染 相当于加粗 // builder.gimp(new RippleGimpyRenderer()); // 修剪--一般不会用 // builder.gimp(new ShearGimpyRenderer(Color.red)); // 加网--第一个参数是横线颜色，第二个参数是竖线颜色 // builder.gimp(new FishEyeGimpyRenderer(Color.red,Color.yellow)); // 加入阴影效果 默认3，75 // builder.gimp(new DropShadowGimpyRenderer()); // 创建对象 Captcha captcha = builder.build(); req.getSession().setAttribute("simpleCaptcha", captcha); resp.setHeader("Cache-Control", "private,no-cache,no-store"); resp.setContentType("image/png"); try { OutputStream os = resp.getOutputStream(); ImageIO.write(captcha.getImage(), "png", os); os.close(); } catch (IOException e) { e.printStackTrace(); } } public Color getRandomColor() { int n = RandomUtils.nextInt(100); if (n % 3 == 1) { return Color.RED; } else if (n % 3 == 2) { return Color.BLUE; } return Color.GREEN; } }