java前后端图形验证码源码

import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.LinearGradientPaint; import java.awt.Paint; 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; 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{ //字符串的长度 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 + (6.2831853