验证码生成

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;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class AuthCodeUtil

{

  private static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";

  private static final String SESSION_KEY_BM_CODE = "SESSION_KEY_BM_CODE";

  private static Random random = new Random();

  public static void createAuthCodeAndOutput(int wide, int high, int size, HttpServletRequest request, HttpServletResponse response)

    throws IOException

  {

    response.setHeader("Pragma", "no-cache");

    response.setHeader("Cache-Control", "no-cache");

    response.setDateHeader("Expires", 0L);

    response.setContentType("image/gif");

    String authCode = createAuthCode(size);

    SessionManager.setAttribute(request, "SESSION_KEY_BM_CODE", authCode);

    OutputStream os = null;

    try {

      os = response.getOutputStream();

    } catch (IOException e) {

      e.printStackTrace();

    }

    outputImage(wide, high, os, authCode);

  }

  public static boolean checkAuthCode(String authCode, HttpServletRequest request, HttpServletResponse response)

    throws IOException

  {

    String sessionAuthCode = (String)SessionManager.getAttribute(request, "SESSION_KEY_BM_CODE");

    return authCode.equalsIgnoreCase(sessionAuthCode);

  }

  public static String createAuthCode(int authSize)

  {

    return createAuthCode(authSize, "23456789ABCDEFGHJKLMNPQRSTUVWXYZ");

  }

  public static String createAuthCode(int authSize, String sources)

  {

    if ((sources == null) || (sources.length() == 0)) {

      sources = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";

    }

    int codesLen = sources.length();

    Random rand = new Random(System.currentTimeMillis());

    StringBuilder authCode = new StringBuilder(authSize);

    for (int i = 0; i < authSize; ++i) {

      authCode.append(sources.charAt(rand.nextInt(codesLen - 1)));

    }

    return authCode.toString();

  }

  public static void outputImage(int wide, int high, 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(wide, high, fos, code);

      fos.close();

    } catch (IOException e) {

      throw e;

    }

  }

  public static void outputImage(int wide, int high, OutputStream os, String code)

    throws IOException

  {

    int w = wide;

    int h = high;

    int authSize = code.length();

    BufferedImage image = new BufferedImage(w, h, 1);

    Random rand = new Random();

    Graphics2D g2 = image.createGraphics();

    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

    Color[] colors = new Color[5];

    Color[] colorSpaces = { 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);

    g2.fillRect(0, 0, w, h);

    Color c = getRandColor(200, 250);

    g2.setColor(c);

    g2.fillRect(0, 2, w, h - 4);

    Random random = new Random();

    g2.setColor(getRandColor(160, 200));

    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);

    }

    float yawpRate = 0.05F;

    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);

    g2.setColor(getRandColor(100, 160));

    int fontSize = h - 4;

    Font font = new Font("Fixedsys", 1, fontSize);

    g2.setFont(font);

    char[] chars = code.toCharArray();

    for (int i = 0; i < authSize; ++i) {

      AffineTransform affine = new AffineTransform();

      affine.setToRotation(0.7853981633974483D * rand.nextDouble() * ((rand.nextBoolean()) ? 1 : -1), w / authSize * i + fontSize / 2, h / 2);

      g2.setTransform(affine);

      g2.drawChars(chars, i, 1, (w - 10) / authSize * 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 <<= 8;

      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 = (period >> 1) * Math.sin(i / period + 6.283185307179586D * phase / 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;

    boolean borderGap = true;

    int frames = 20;

    int phase = 7;

    for (int i = 0; i < w1; ++i) {

      double d = (period >> 1) * Math.sin(i / period + 6.283185307179586D * phase / 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("D:/verifies");

    int w = 300; int h = 80;

    for (int i = 0; i < 50; ++i) {

      String authCode = createAuthCode(4);

      File file = new File(dir, new StringBuilder().append(authCode).append(".jpg").toString());

      outputImage(w, h, file, authCode);

    }

  }

}