java生成验证码

心已赠人 2022-07-13 06:52 259阅读 0赞

前端调用：

后台代码：

private int					w				= 70;
    
    	private int					h				= 26;
    	
    	/**
    	 * 生成验证码
    	 */
    	@RequestMapping
    	public void captcha(String width, String height, HttpServletResponse response, Model model)
    	{
    		OutputStream out = null;
    		try
    		{
    			response.setHeader("Pragma", "no-cache");
    			response.setHeader("Cache-Control", "no-cache");
    			response.setDateHeader("Expires", 0);
    			response.setContentType("image/jpeg");
    			if (StringUtils.isNumeric(width) && StringUtils.isNumeric(height))
    			{
    				w = NumberUtils.toInt(width);
    				h = NumberUtils.toInt(height);
    			}
    			BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
    			Graphics g = image.getGraphics();
    			g.setColor(getRandColor(220, 250));// 生成背景
    			g.fillRect(0, 0, w, h);
    			for (int i = 0; i < 8; i++) // 加入干扰线条
    			{
    				g.setColor(getRandColor(40, 150));
    				Random random = new Random();
    				int x = random.nextInt(w);
    				int y = random.nextInt(h);
    				int x1 = random.nextInt(w);
    				int y1 = random.nextInt(h);
    				g.drawLine(x, y, x1, y1);
    			}
    			String s = createCharacter(g);// 生成字符
    			SessionUtils.put(Constants.SESSION_KEY_CAPTCHA, s);
    			g.dispose();
    			out = response.getOutputStream();
    			ImageIO.write(image, "JPEG", out);
    			out.close();
    		}
    		catch (Exception e)
    		{
    			logger.error("Write Captcha Error", e);
    		}
    		finally
    		{
    			IOUtils.closeQuietly(out);
    		}
    	}
    
    	private Color getRandColor(int fc, int bc)
    	{
    		int f = fc;
    		int b = bc;
    		Random random = new Random();
    		if (f > 255)
    		{
    			f = 255;
    		}
    		if (b > 255)
    		{
    			b = 255;
    		}
    		return new Color(f + random.nextInt(b - f), f + random.nextInt(b - f), f + random.nextInt(b - f));
    	}
    
    	private String createCharacter(Graphics g)
    	{
    		char[] codeSeq =
    		{ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9' };
                    //字体：宋体, 新宋体, 黑体, 楷体, 隶书
    		String[] fontTypes =
    		{ "\u5b8b\u4f53", "\u65b0\u5b8b\u4f53", "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66" };
    		Random random = new Random();
    		StringBuilder s = new StringBuilder();
    		for (int i = 0; i < 4; i++)
    		{
    			String r = String.valueOf(codeSeq[random.nextInt(codeSeq.length)]);
    			g.setColor(new Color(50 + random.nextInt(100), 50 + random.nextInt(100), 50 + random.nextInt(100)));
    			g.setFont(new Font(fontTypes[random.nextInt(fontTypes.length)], Font.BOLD, 26));
    			g.drawString(r, 15 * i + 5, 19 + random.nextInt(8));
    			s.append(r);
    		}
    		return s.toString();
    	}