生成验证码

<pre name="code" class="java"> import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import com.paic.pafa.web.BaseController; import com.pingan.stock.omm.http.um.constants.KeyConstants; /** * 描述: 图片验证 */ @Controller public class DynamicImgController extends BaseController { /** 候选字 */ public static final String[] word = { "a", "b", "d", "e", "f", "g", "h", "j", "k", "m", "n", "p", "q", "r", "s", "t", "u", "y", "A", "B", "D", "E", "F", "G", "H", "J", "K", "L", "M", "N", "P", "Q", "R", "S", "T", "U", "Y", "1", "2", "3", "4", "5", "6", "7", "8", "9" }; /** 图片字体 */ public static final String FONT = "Times New Roman"; /** 图片文件格式 */ public static final String JPEG = "JPEG"; /** 图片大小 */ public static final int width = 60, height = 20; /** * @标题: 生成随即的颜色 */ Color getRandColor(int fc, int bc) { // 给定范围获得随机颜色 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); } /** * @标题: 生成图形验证码图片,并通过IO输出到浏览器 */ @RequestMapping("/http/um/img") public void dynamicImg(HttpServletRequest request, HttpServletResponse response) { HttpSession httpSession = request.getSession(); // 设置页面不缓存 response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); // 在内存中创建图象 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 获取图形上下文 Graphics g = image.getGraphics(); // 生成随机类 Random random = new Random(); // 设定背景色 g.setColor(getRandColor(200, 250)); g.fillRect(0, 0, width, height); // 设定字体 g.setFont(new Font(FONT, Font.PLAIN, 18)); // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到 g.setColor(getRandColor(160, 200)); for (int i = 0; i < 200; 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); } // 取随机产生的认证码(4位数字) String sRand = ""; for (int i = 0; i < 4; i++) { int num = random.nextInt(word.length - 1); String randWord = word[num]; sRand += randWord; // 将认证码显示到图象中 g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110))); // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成 g.drawString(randWord, 13 * i + 6, 16); } // 主页获取值 httpSession.setAttribute(KeyConstants.DYNAMIC_TICKET, sRand); // 图象生效 g.dispose(); // 输出图象到页面 try { ImageIO.write(image, JPEG, response.getOutputStream()); } catch (Exception ex) { logger.info(ex.getMessage()); } } }