XX需求分析系統每日進度（一）

添加驗證碼的更新和驗證功能

思路：後臺隨機生成四位數字或字母組合的字符串，並保存在Session域中，爲保證安全以圖片的形式返回給前臺，通過比對前臺傳遞的驗證碼內容和Session域是否一致進行校驗

• 主要代碼如下

1. 生成驗證碼工具類

public class RandomValidateCodeUtil {
    public static final String RANDOMCODEKEY= "RANDOMVALIDATECODEKEY";//放到session中的key
//    private String randString = "0123456789";//隨機產生只有數字的字符串 private String
    //private String randString = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";//隨機產生只有字母的字符串
    private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";//隨機產生數字與字母組合的字符串
    private int width = 95;// 圖片寬
    private int height = 25;// 圖片高
    private int lineSize = 40;// 干擾線數量
    private int stringNum = 4;// 隨機產生字符數量

    private static final Logger logger = LoggerFactory.getLogger(RandomValidateCodeUtil.class);

    private Random random = new Random();

    /**
     * 獲得字體
     */
    private Font getFont() {
        return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
    }

    /**
     * 獲得顏色
     */
    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);
    }

    /**
     * 生成隨機圖片
     */
    public void getRandcode(HttpServletRequest request, HttpServletResponse response) {
        HttpSession session = request.getSession();
        // BufferedImage類是具有緩衝區的Image類,Image類是用於描述圖像信息的類
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        Graphics g = image.getGraphics();// 產生Image對象的Graphics對象,改對象可以在圖像上進行各種繪製操作
        g.fillRect(0, 0, width, height);//圖片大小
        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));//字體大小
        g.setColor(getRandColor(110, 133));//字體顏色
        // 繪製干擾線
        for (int i = 0; i <= lineSize; i++) {
            drowLine(g);
        }
        // 繪製隨機字符
        String randomString = "";
        for (int i = 1; i <= stringNum; i++) {
            randomString = drowString(g, randomString, i);
        }
        logger.info(randomString);
        //將生成的隨機字符串保存到session中
        session.removeAttribute(RANDOMCODEKEY);
        session.setAttribute(RANDOMCODEKEY, randomString);
        g.dispose();
        try {
            // 將內存中的圖片通過流動形式輸出到客戶端
            ImageIO.write(image, "JPEG", response.getOutputStream());
        } catch (Exception e) {
            logger.error("將內存中的圖片通過流動形式輸出到客戶端失敗>>>>   ", e);
        }

    }

    /**
     * 繪製字符串
     */
    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;
    }

    /**
     * 繪製干擾線
     */
    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);
    }

    /**
     * 獲取隨機的字符
     */
    public String getRandomString(int num) {
        return String.valueOf(randString.charAt(num));
    }
}

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2. 後臺返回驗證碼給前臺

/**
     * 生成驗證碼
     */
    @RequestMapping(value = "/getVerify")
    public void getVerify(HttpServletRequest request, HttpServletResponse response) {
        try {
            response.setContentType("image/jpeg");//設置相應類型,告訴瀏覽器輸出的內容爲圖片
            response.setHeader("Pragma", "No-cache");//設置響應頭信息，告訴瀏覽器不要緩存此內容
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expire", 0);
            RandomValidateCodeUtil randomValidateCode = new RandomValidateCodeUtil();
            randomValidateCode.getRandcode(request, response);//輸出驗證碼圖片方法
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

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3. 後臺校驗驗證碼

 /**
     * 校驗驗證碼
     */
    @RequestMapping("/checkVerify")
    @ResponseBody
    public boolean checkVerify(@RequestBody Map<String, Object> requestMap, HttpServletRequest request) {
        try{
            HttpSession session = request.getSession();
            //從session中獲取隨機數
            System.out.println("requestMap = " + requestMap.toString());
            String inputStr = requestMap.get("inputStr").toString();
            System.out.println(inputStr);

            String random = (String) session.getAttribute("RANDOMVALIDATECODEKEY");
            if (random == null) {
                return false;
            }
            if (random.equals(inputStr)) {
                return true;
            } else {
                return false;
            }
        }catch (Exception e){
            e.printStackTrace();
            return false;
        }
    }

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明天任務：學習樹形結構，並嘗試將學科分類替換爲樹形結構