JAVA產生驗證碼代碼

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產生base64格式圖片驗證碼

 

  1  /**  2      * 產生驗證碼  3      * 改造產生驗證碼的方式，將圖片base64形式傳到前台，而不是直接傳驗證碼到前台  4      * @return  5      * @throws IOException  6      */  7     public void imageCode() throws IOException {  8         HttpServletResponse resp = CommandContext.getResponse();  9         HttpServletRequest req = CommandContext.getRequest(); 10         String method= req.getMethod(); 11         if("OPTIONS".equals(method)){ 12             return ; 13         } 14         Map map=new HashMap(); 15  16         // 在記憶體中建立圖象 17         int width = 65, height = 38; 18         BufferedImage image = new BufferedImage(width, height, 19                 BufferedImage.TYPE_INT_RGB); 20         // 擷取圖形上下文 21         Graphics g = image.getGraphics(); 22         // 產生隨機類 23         Random random = new Random(); 24         // 設定背景色 25         g.setColor(getRandColor(230, 255)); 26         g.fillRect(0, 0, 100, 40); 27         // 設定字型 28         g.setFont(new Font("Arial", Font.CENTER_BASELINE | Font.ITALIC, 20)); 29         // 產生0條幹擾線， 30         g.drawLine(0, 0, 0, 0); 31  32         //存放驗證碼 33         StringBuffer sRand = new StringBuffer(); 34         for (int i = 0; i < charCount; i++) { 35             String singleCode = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]); 36             sRand.append(singleCode); 37             // 將認證碼顯示到圖象中 38             g.setColor(getRandColor(100, 150));// 調用函數出來的顏色相同，可能是因為種子太接近，所以只能直接產生 39             g.drawString(singleCode, 14 * i + 5, 25); 40         } 41         for(int i=0;i<(random.nextInt(5)+5);i++){ 42             g.setColor(new Color(random.nextInt(255)+1,random.nextInt(255)+1,random.nextInt(255)+1)); 43             g.drawLine(random.nextInt(70),random.nextInt(40),random.nextInt(70),random.nextInt(40)); 44             g.drawLine(random.nextInt(70),random.nextInt(40),random.nextInt(70),random.nextInt(40)); 45         } 46  47         HttpSession session = req.getSession(); 48         //擷取clientid 49         String clientId= SystemUtil.getClientId(req); 50         if(StringUtils.isEmpty(clientId)){ 51             //產生clientid 52             String userAgent=req.getHeader("User-Agent"); 53             String sessionId=session.getId(); 54             String cip= IpPolicy.getClientIP(req); 55             clientId=CodeUtil.genClientId(sessionId,cip,userAgent); 56         } 57         map.put("clientId", clientId); 58         if (isValidateCodeCaseSensitive) { 59             session.setAttribute("randomCode", sRand.toString()); 60             SystemUtil.push2Cache(clientId, sRand.toString()); 61         } else { 62             session.setAttribute("randomCode", sRand.toString().toLowerCase()); 63             SystemUtil.push2Cache(clientId, sRand.toString().toLowerCase()); 64         } 65         // 圖象生效 66         g.dispose(); 67         try{ 68  69             ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); 70             ImageIO.write(image, "jpg", outputStream); 71             BASE64Encoder encoder = new BASE64Encoder(); 72             String base64Img = encoder.encode(outputStream.toByteArray()); 73             base64Img="data:image/jpg;base64, "+base64Img.replaceAll("\n", "").replaceAll("\r", "");//刪除 \r\n; 74             map.put("verCode", base64Img); 75             Object jsonObj = JSONSerializer.toJSON(map); 76             byte[] json = jsonObj.toString().getBytes("UTF-8"); 77             resp.setContentType("text/plain;chartset=utf-8"); 78             resp.setHeader("Cache-Control", "no-cache"); 79             resp.setHeader("Expires", "0"); 80             resp.setIntHeader("Content-Length", json.length); 81             ServletOutputStream responseOutputStream = resp.getOutputStream(); 82             responseOutputStream.write(json); 83             // 以下關閉輸入資料流！ 84             responseOutputStream.flush(); 85             responseOutputStream.close(); 86             // 獲得頁面key值 87             return ; 88         } catch (IOException e) { 89             logger.error("生產驗證碼出錯",e); 90             throw new SystemException("生產驗證碼出錯",e); 91         } 92     } 93  94  95     /** 96      * 給定範圍獲得隨機顏色 97      * 98      * @param fc 99      * @param bc100      * @return101      */102     Color getRandColor(int fc, int bc) {103         Random random = new Random();104         if (fc > 255)105             fc = 255;106         if (bc > 255)107             bc = 255;108         int r = fc + random.nextInt(bc - fc);109         int g = fc + random.nextInt(bc - fc);110         int b = fc + random.nextInt(bc - fc);111         return new Color(r, g, b);112     }

 

JAVA產生驗證碼代碼