
java后台返回base64图形编码
发布日期:2022-02-23 07:42:35
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分类:技术文章
本文共 6874 字,大约阅读时间需要 22 分钟。
文章目录
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(); }
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初次前来,多多关照!
[***.217.46.12]2023年05月28日 13时15分00秒
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