java生成随机图片验证码
一、创建图片验证码生成工具类
1 /** 2 * 图片验证码生成工具类 3 */ 4 public class validationCodeUtil { 5 6 public static final String RANDOMCODEKEY= "RANDOMREDISKEY";//放到session中的key 7 private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生数字与字母组合的字符串 8 private int width = 95;// 图片宽 9 private int height = 25;// 图片高 10 private int lineSize = 40;// 干扰线数量 11 private int stringNum = 4;// 随机产生字符数量 12 13 private Random random = new Random(); 14 15 /** 16 * 获得字体 17 */ 18 private Font getFont() { 19 return new Font("Fixedsys", Font.CENTER_BASELINE, 18); 20 } 21 22 /** 23 * 获得颜色 24 */ 25 private Color getRandColor(int fc, int bc) { 26 if (fc > 255) 27 fc = 255; 28 if (bc > 255) 29 bc = 255; 30 int r = fc + random.nextInt(bc - fc - 16); 31 int g = fc + random.nextInt(bc - fc - 14); 32 int b = fc + random.nextInt(bc - fc - 18); 33 return new Color(r, g, b); 34 } 35 36 /** 37 * 生成随机图片 38 */ 39 public void getRandcode(HttpServletRequest request, HttpServletResponse response) { 40 HttpSession session = request.getSession(); 41 // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类 42 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR); 43 Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作 44 g.fillRect(0, 0, width, height);//图片大小 45 g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));//字体大小 46 g.setColor(getRandColor(110, 133));//字体颜色 47 // 绘制干扰线 48 for (int i = 0; i <= lineSize; i++) { 49 drowLine(g); 50 } 51 // 绘制随机字符 52 String randomString = ""; 53 for (int i = 1; i <= stringNum; i++) { 54 randomString = drowString(g, randomString, i); 55 } 56 //将生成的随机字符串保存到session中 57 session.removeAttribute(RANDOMCODEKEY); 58 session.setAttribute(RANDOMCODEKEY, randomString); 59 //设置失效时间1分钟 60 session.setMaxInactiveInterval(60); 61 g.dispose(); 62 try { 63 // 将内存中的图片通过流动形式输出到客户端 64 ImageIO.write(image, "JPEG", response.getOutputStream()); 65 } catch (Exception e) { 66 } 67 68 } 69 70 /** 71 * 绘制字符串 72 */ 73 private String drowString(Graphics g, String randomString, int i) { 74 g.setFont(getFont()); 75 g.setColor(new Color(random.nextInt(101), random.nextInt(111), random 76 .nextInt(121))); 77 String rand = String.valueOf(getRandomString(random.nextInt(randString 78 .length()))); 79 randomString += rand; 80 g.translate(random.nextInt(3), random.nextInt(3)); 81 g.drawString(rand, 13 * i, 16); 82 return randomString; 83 } 84 85 /** 86 * 绘制干扰线 87 */ 88 private void drowLine(Graphics g) { 89 int x = random.nextInt(width); 90 int y = random.nextInt(height); 91 int xl = random.nextInt(13); 92 int yl = random.nextInt(15); 93 g.drawLine(x, y, x + xl, y + yl); 94 } 95 96 /** 97 * 获取随机的字符 98 */ 99 public String getRandomString(int num) { 100 return String.valueOf(randString.charAt(num)); 101 }
二、controller层调用
1 @Controller 2 public class CodeTest { 3 /** 4 * 图片验证码测试类 5 * @param request 6 * @param response 7 * @throws Exception 8 */ 9 @RequestMapping("/createImg") 10 public void createImg(HttpServletRequest request, HttpServletResponse response) throws Exception { 11 try { 12 response.setContentType("image/jpeg");//设置相应类型,告诉浏览器输出的内容为图片 13 response.setHeader("Pragma", "No-cache");//设置响应头信息，告诉浏览器不要缓存此内容 14 response.setHeader("Cache-Control", "no-cache"); 15 response.setDateHeader("Expire", 0); 16 validationCodeUtil randomValidateCode = new validationCodeUtil(); 17 randomValidateCode.getRandcode(request, response);//输出验证码图片 18 } catch(Exception e){ 19 e.printStackTrace(); 20 } 21 //从session中取出随机验证码 22 System.out.println(request.getSession().getAttribute("RANDOMREDISKEY")); 23 } 24 }
三、运行项目访问地址
