Java创建图形验证码工具类

落日映苍穹つ 2021-11-29 20:20 391阅读 0赞

public class RandomValidateCodeUtil { 
    
    	public static final String RANDOMCODEKEY = "RANDOMVALIDATECODEKEY";// 放到session中的key
    	private String randString = "0123456789";// 随机产生只有数字的字符串 private String
    	// private String randString = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生只有字母的字符串
    	// private String randString =
    	// "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生数字与字母组合的字符串
    	private int width = 95;// 图片宽
    	private int height = 25;// 图片高
    	private int lineSize = 40;// 干扰线数量
    	private int stringNum = 4;// 随机产生字符数量
    
    	private static final Logger logger = LoggerFactory.getLogger(RandomValidateCodeUtil.class);
    
    	private Random random = new Random();
    
    	/** * 获得字体 */
    	private Font getFont() { 
    		return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
    	}
    
    	/** * 获得颜色 */
    	private Color getRandColor(int fc, int bc) { 
    		if (fc > 255)
    			fc = 255;
    		if (bc > 255)
    			bc = 255;
    		int r = fc + random.nextInt(bc - fc - 16);
    		int g = fc + random.nextInt(bc - fc - 14);
    		int b = fc + random.nextInt(bc - fc - 18);
    		return new Color(r, g, b);
    	}
    
    	/** * 生成随机图片 */
    	public void getRandcode(HttpServletRequest request, HttpServletResponse response) { 
    		HttpSession session = request.getSession();
    		// BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
    		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
    		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
    		g.fillRect(0, 0, width, height);// 图片大小
    		g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));// 字体大小
    		g.setColor(getRandColor(110, 133));// 字体颜色
    		// 绘制干扰线
    		for (int i = 0; i <= lineSize; i++) { 
    			drowLine(g);
    		}
    		// 绘制随机字符
    		String randomString = "";
    		for (int i = 1; i <= stringNum; i++) { 
    			randomString = drowString(g, randomString, i);
    		}
    		logger.info(randomString);
    		// 将生成的随机字符串保存到session中
    		session.removeAttribute(RANDOMCODEKEY);
    		session.setAttribute(RANDOMCODEKEY, randomString);
    		g.dispose();
    		try { 
    			// 将内存中的图片通过流动形式输出到客户端
    			ImageIO.write(image, "JPEG", response.getOutputStream());
    		} catch (Exception e) { 
    			logger.error("将内存中的图片通过流动形式输出到客户端失败>>>> ", e);
    		}
    
    	}
    
    	/** * 绘制字符串 */
    	private String drowString(Graphics g, String randomString, int i) { 
    		g.setFont(getFont());
    		g.setColor(new Color(random.nextInt(101), random.nextInt(111), random.nextInt(121)));
    		String rand = String.valueOf(getRandomString(random.nextInt(randString.length())));
    		randomString += rand;
    		g.translate(random.nextInt(3), random.nextInt(3));
    		g.drawString(rand, 13 * i, 16);
    		return randomString;
    	}
    
    	/** * 绘制干扰线 */
    	private void drowLine(Graphics g) { 
    		int x = random.nextInt(width);
    		int y = random.nextInt(height);
    		int xl = random.nextInt(13);
    		int yl = random.nextInt(15);
    		g.drawLine(x, y, x + xl, y + yl);
    	}
    
    	/** * 获取随机的字符 */
    	public String getRandomString(int num) { 
    		return String.valueOf(randString.charAt(num));
    	}
    
    	public static Boolean checkVerify(String verifiCode, HttpSession httpSession) { 
    		if (StringUtils.isEmpty(verifiCode)) { 
    			return false;
    		}
    		String random = (String) httpSession.getAttribute("RANDOMVALIDATECODEKEY");
    		if (StringUtils.isEmpty(random)) { 
    			return false;
    		}
    		if (!random.equals(verifiCode)) { 
    			return false;
    		}
    		return true;
    	}
    }