servlet生成图形验证码

生成验证码的工具类

package com.prosysoft.biz.lhk.img;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.RenderingHints;import java.awt.geom.AffineTransform;import java.awt.image.BufferedImage;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.util.Arrays;import java.util.Random;import javax.imageio.ImageIO;//图片验证码public class VerifyCodeUtils {      // 使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符      public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";      private static Random random = new Random();      /**      * 使用系统默认字符源生成验证码      *       * @param verifySize      *            验证码长度      * @return      */      public static String generateVerifyCode(int verifySize) {          return generateVerifyCode(verifySize, VERIFY_CODES);      }      /**      * 使用指定源生成验证码      *       * @param verifySize      *            验证码长度      * @param sources      *            验证码字符源      * @return      */      public static String generateVerifyCode(int verifySize, String sources) {          if (sources == null || sources.length() == 0) {              sources = VERIFY_CODES;          }          int codesLen = sources.length();          Random rand = new Random(System.currentTimeMillis());          StringBuilder verifyCode = new StringBuilder(verifySize);          for (int i = 0; i < verifySize; i++) {              verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));          }          return verifyCode.toString();      }      /**      * 生成随机验证码文件,并返回验证码值      *       * @param w      * @param h      * @param outputFile      * @param verifySize      * @return      * @throws IOException      */      public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {          String verifyCode = generateVerifyCode(verifySize);          outputImage(w, h, outputFile, verifyCode);          return verifyCode;      }      /**      * 输出随机验证码图片流,并返回验证码值      *       * @param w      * @param h      * @param os      * @param verifySize      * @return      * @throws IOException      */      public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException {          String verifyCode = generateVerifyCode(verifySize);          outputImage(w, h, os, verifyCode);          return verifyCode;      }      /**      * 生成指定验证码图像文件      *       * @param w      * @param h      * @param outputFile      * @param code      * @throws IOException      */      public static void outputImage(int w, int h, File outputFile, String code) throws IOException {          if (outputFile == null) {              return;          }          File dir = outputFile.getParentFile();          if (!dir.exists()) {              dir.mkdirs();          }          try {              outputFile.createNewFile();              FileOutputStream fos = new FileOutputStream(outputFile);              outputImage(w, h, fos, code);              fos.close();          } catch (IOException e) {              throw e;          }      }      /**      * 输出指定验证码图片流      *       * @param w      * @param h      * @param os      * @param code      * @throws IOException      */      public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {          int verifySize = code.length();          BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);          Random rand = new Random();          Graphics2D g2 = image.createGraphics();          g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);          Color[] colors = new Color[5];          Color[] colorSpaces = new Color[] { Color.WHITE, Color.CYAN, Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE, Color.PINK, Color.YELLOW };          float[] fractions = new float[colors.length];          for (int i = 0; i < colors.length; i++) {              colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];              fractions[i] = rand.nextFloat();          }          Arrays.sort(fractions);          g2.setColor(Color.GRAY);// 设置边框色          g2.fillRect(0, 0, w, h);          Color c = getRandColor(200, 250);          g2.setColor(c);// 设置背景色          g2.fillRect(0, 2, w, h - 4);          // 绘制干扰线          Random random = new Random();          g2.setColor(getRandColor(160, 200));// 设置线条的颜色          for (int i = 0; i < 20; i++) {              int x = random.nextInt(w - 1);              int y = random.nextInt(h - 1);              int xl = random.nextInt(6) + 1;              int yl = random.nextInt(12) + 1;              g2.drawLine(x, y, x + xl + 40, y + yl + 20);          }          // 添加噪点          float yawpRate = 0.05f;// 噪声率          int area = (int) (yawpRate * w * h);          for (int i = 0; i < area; i++) {              int x = random.nextInt(w);              int y = random.nextInt(h);              int rgb = getRandomIntColor();              image.setRGB(x, y, rgb);          }          shear(g2, w, h, c);// 使图片扭曲          g2.setColor(getRandColor(100, 160));          int fontSize = h - 4;          Font font = new Font("Algerian", Font.ITALIC, fontSize);          g2.setFont(font);          char[] chars = code.toCharArray();          for (int i = 0; i < verifySize; i++) {              AffineTransform affine = new AffineTransform();              affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);              g2.setTransform(affine);              g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);          }          g2.dispose();          ImageIO.write(image, "jpg", os);      }      private static Color getRandColor(int fc, int bc) {          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);      }      private static int getRandomIntColor() {          int[] rgb = getRandomRgb();          int color = 0;          for (int c : rgb) {              color = color << 8;              color = color | c;          }          return color;      }      private static int[] getRandomRgb() {          int[] rgb = new int[3];          for (int i = 0; i < 3; i++) {              rgb[i] = random.nextInt(255);          }          return rgb;      }      private static void shear(Graphics g, int w1, int h1, Color color) {          shearX(g, w1, h1, color);          shearY(g, w1, h1, color);      }      private static void shearX(Graphics g, int w1, int h1, Color color) {          int period = random.nextInt(2);          boolean borderGap = true;          int frames = 1;          int phase = random.nextInt(2);          for (int i = 0; i < h1; i++) {              double d = (double) (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);              g.copyArea(0, i, w1, 1, (int) d, 0);              if (borderGap) {                  g.setColor(color);                  g.drawLine((int) d, i, 0, i);                  g.drawLine((int) d + w1, i, w1, i);              }          }      }      private static void shearY(Graphics g, int w1, int h1, Color color) {          int period = random.nextInt(40) + 10; // 50;          boolean borderGap = true;          int frames = 20;          int phase = 7;          for (int i = 0; i < w1; i++) {              double d = (double) (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);              g.copyArea(i, 0, 1, h1, 0, (int) d);              if (borderGap) {                  g.setColor(color);                  g.drawLine(i, (int) d, i, 0);                  g.drawLine(i, (int) d + h1, i, h1);              }          }      }      /*      * public static void main(String[] args) throws IOException { File dir =      * new File("F:/verifies"); int w = 200, h = 80; for (int i = 0; i < 50;      * i++) { String verifyCode = generateVerifyCode(4); File file = new      * File(dir, verifyCode + ".jpg"); outputImage(w, h, file, verifyCode); } }      */  }  

程序中进行调用

//生成图片    @RequestMapping(value = "/getImage2")    public void getService2(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {          response.setHeader("Pragma", "No-cache");          response.setHeader("Cache-Control", "no-cache");          response.setDateHeader("Expires", 0);          response.setContentType("image/jpeg");          // 生成随机字串          String verifyCode = VerifyCodeUtils.generateVerifyCode(4);          // 存入会话session          HttpSession session = request.getSession(true);          // 删除以前的          session.removeAttribute("verifyCode");          session.setAttribute("verifyCode", verifyCode.toLowerCase());          // 生成图片          int w = 100, h = 30;          VerifyCodeUtils.outputImage(w, h, response.getOutputStream(), verifyCode);    }

图形效果