1.如何保证同一浏览器保存的内容相同
请求图片验证码之前判断SessionStorage是否有KEY,如果没就创建,然后保存SessionStorage,如果有自己直接作为参数发送Ajax请求获取图片验证码
- 前端通过ajax发送一个图片验证码请求,携带者KEY
- 后端收到请求,生成图片验证码的值
- 把图片验证码的值存储到Redis,以前段传入的key作为Redis的key
- 把图片验证码的值合并到一个图片中
- 把图片基于Base64编码层字符串,响应给前端
- 前端拿到base64字符串,进行图片的展示,用户输入图片验证码
- 前台提交注册请求 ,验证图片验证码(key也要携带),后端把前端传入的图片验证码的值和Redis中的图片验证码的值做比
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@Override public String imageCode(String key) { if(StringUtils.isEmpty(key)){ throw new RuntimeException("验证码获取失败,请刷新页面重试"); } //1.请求图片验证码之前判断SessionStorage是否有KEY, // 如果没就创建,然后保存SessionStorage,如果有自己直接作为参数发送Ajax请求获取图片验证码 //2.前端通过ajax发送一个图片验证码请求,携带者KEY //3.后端收到请求,生成图片验证码的值 //4.把图片验证码的值存储到Redis,以前段传入的key作为Redis的key //生成随机数 String randomString = StrUtils.getComplexRandomString(4); try { String verifyCode = VerifyCodeUtils.VerifyCode(150, 50, randomString); AjaxResult setex = redisFegin.setex(key, 10000, randomString); if (!setex.isSuccess()){ throw new RuntimeException("图片保存失败"); } return verifyCode; } catch (IOException e) { throw new RuntimeException("图片保存Redis失败"); } }
还有两个工具类
一个生成随机数
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package cn.jiedada.hrm.util; import java.util.ArrayList; import java.util.List; import java.util.Random; /** * @author yaohuaipeng * @date 2018/10/26-16:16 */ public class StrUtils { /** * 把逗号分隔的字符串转换字符串数组 * * @param str * @return */ public static String[] splitStr2StrArr(String str,String split) { if (str != null && !str.equals("")) { return str.split(split); } return null; } /** * 把逗号分隔字符串转换List的Long * * @param str * @return */ public static List<Long> splitStr2LongArr(String str) { String[] strings = splitStr2StrArr(str,","); if (strings == null) return null; List<Long> result = new ArrayList<>(); for (String string : strings) { result.add(Long.parseLong(string)); } return result; } /** * 把逗号分隔字符串转换List的Long * * @param str * @return */ public static List<Long> splitStr2LongArr(String str,String split) { String[] strings = splitStr2StrArr(str,split); if (strings == null) return null; List<Long> result = new ArrayList<>(); for (String string : strings) { result.add(Long.parseLong(string)); } return result; } public static String getRandomString(int length) { String str = "0123456789"; Random random = new Random(); StringBuffer sb = new StringBuffer(); for (int i = 0; i < length; i++) { int number = random.nextInt(10); sb.append(str.charAt(number)); } return sb.toString(); } public static String getComplexRandomString(int length) { String str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; Random random = new Random(); StringBuffer sb = new StringBuffer(); for (int i = 0; i < length; i++) { int number = random.nextInt(62); sb.append(str.charAt(number)); } return sb.toString(); } public static String convertPropertiesToHtml(String properties){ //1:容量:6:32GB_4:样式:12:塑料壳 StringBuilder sBuilder = new StringBuilder(); String[] propArr = properties.split("_"); for (String props : propArr) { String[] valueArr = props.split(":"); sBuilder.append(valueArr[1]).append(":").append(valueArr[3]).append("<br>"); } return sBuilder.toString(); } }
一个生成图片的工具类(这里也可以接入第三方)
前端不可以接收String转化为图片但可以通过base64的String转为图片,这里我们工具类里面就可以生成前端能够直接转化为图片的参数
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package cn.jiedada.hrm.util; import sun.misc.BASE64Encoder; import javax.imageio.ImageIO; import java.awt.*; import java.awt.geom.AffineTransform; import java.awt.image.BufferedImage; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStream; import java.util.Arrays; import java.util.Random; /** * Created by Wzy * on 2018/5/11 */ 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(); } /** * 输出指定验证码图片流 * */ 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); } } } /** * 获取随机验证码及其加密图片 * 使用BASE64编码 * 返回一个BASE64 */ public static String VerifyCode(int w, int h, int size) throws IOException { BASE64Encoder encoder = new BASE64Encoder(); String code = generateVerifyCode(size).toLowerCase(); ByteArrayOutputStream data = new ByteArrayOutputStream(); outputImage(w, h, data, code); return encoder.encode(data.toByteArray()); } /** * 传入参数获得对应的图片验证 * */ public static String VerifyCode(int w, int h, String code) throws IOException { BASE64Encoder encoder = new BASE64Encoder(); ByteArrayOutputStream data = new ByteArrayOutputStream(); outputImage(w, h, data, code); return encoder.encode(data.toByteArray()); } public static void main(String[] args) throws Exception{ System.out.println(VerifyCode(100, 30, 6)); } }