一、驗證碼工具類
public class CheckCodeUtil { private BufferedImage image; // 圖像 private String str; // 驗證碼 private RandomNumUtil () { init(); } // 獲取實例 public static RandomNumUtil Instance() { return new RandomNumUtil(); } // 獲取圖片 public RenderedImage getImage() { return this.image; } // 獲取6位隨機驗證碼 public String getStr() { return this.str; } private void init() { // 在內存中創建圖象,設置圖像的寬高 int width = 120, height = 30; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 獲取圖形上下文 Graphics g = image.getGraphics(); // 生成隨機類 Random random = new Random(); // 設定背景色 g.setColor(getRandColor(200, 250)); g.fillRect(0, 0, width, height); // 設定字體 g.setFont(new Font("Times New Roman", Font.PLAIN, height - 4)); // 隨機產生155條干擾線,使圖象中的認證碼不易被其它程序探測到 g.setColor(getRandColor(160, 200)); for (int i = 0; i < 155; i++) { int x = random.nextInt(width); int y = random.nextInt(height); int xl = random.nextInt(12); int yl = random.nextInt(12); g.drawLine(x, y, x + xl, y + yl); } // 取隨機產生的認證碼(4位數字) String sRand = ""; for (int i = 0; i < 4; i++) { String rand = String.valueOf(random.nextInt(10)); sRand += rand; // 將認證碼顯示到圖象中 g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110))); // 調用函數出來的顏色相同,可能是因為種子太接近,所以只能直接生成 g.drawString(rand, 13 * i + 26, 25); } // 賦值驗證碼 this.str = sRand; // 圖象生效 g.dispose(); this.image = image; } // 給定范圍獲得隨機顏色 private Color getRandColor(int fc, int bc) { Random random = new Random(); if (fc > 255) fc = 255; if (bc > 255) bc = 255; int r = fc + random.nextInt(bc - fc); int g = fc + random.nextInt(bc - fc); int b = fc + random.nextInt(bc - fc); return new Color(r, g, b); } }
二、獲取驗證碼
@RequestMapping(value = "/check/code") public void init(HttpServletRequest request, HttpServletResponse response) { try { // 生成驗證碼實例 CheckCodeUtil util = ChecoCodeUtil.Instance(); request.getSession().setAttribute("sessionCode", util.getStr()); ServletOutputStream stream = response.getOutputStream(); ImageIO.write(util.getImage(), "JPEG", stream); stream.flush(); stream.close(); } catch (IOException e) { System.out.println("驗證碼生成失敗"); } }
三、頁面
<img src="check/code" id="imgObj" alt="驗證碼">
四、效果