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工具类

package com.liginfo.app.util;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.ByteArrayOutputStream;import java.io.IOException;import java.security.SecureRandom;import java.util.Arrays;import java.util.Random;import javax.imageio.ImageIO;import org.apache.tomcat.util.codec.binary.Base64;import sun.misc.BASE64Encoder;/* * 返回base64验证码的工具类 */public class RandomGraphic {
     // 默认验证码6位  private static int DEFAULT_CODE_NUMBERS = 6;  private static Random random = new SecureRandom();  public static String generateCode(){
       StringBuffer sb = new StringBuffer();    for (int i = 0; i< DEFAULT_CODE_NUMBERS; i++){
         sb.append(random.nextInt(10));    }    return sb.toString();  }  public static String generateCode(int numbers){
       StringBuffer sb = new StringBuffer();    for (int i = 0; i< numbers; i++){
         sb.append(random.nextInt(10));    }    return sb.toString();  }  /**   * 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 final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";  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();  }  /**   * 输出指定验证码图片流   *   * @param w   * @param h   * @param code   * @throws IOException   */  public static String outputImage(int w, int h, 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();    String result = null;    ByteArrayOutputStream out = new ByteArrayOutputStream();    boolean flag = ImageIO.write(image, "GIF", out);    byte[] b = out.toByteArray();    BASE64Encoder base64Encoder = new BASE64Encoder();//    result = base64Encoder.encode(b);    result = Base64.encodeBase64String(b);    return result;  }  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 arg[]){
       for (int i =0;i<2000;i++){
         String s = RandomGraphic.generateCode();      System.out.println(s);    }  }}

使用方法

String code = RandomGraphic.generateVerifyCode(4);		  String data = "";		  try {
   		  		data = RandomGraphic.outputImage(100,30,code);		  		j.setAttributes(map);		  } catch (IOException e) {
   			  j.setSuccess(false);			  j.setMsg("获取验证码失败");		  		// TODO Auto-generated catch block			  e.printStackTrace();		  }

摘自 感谢

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