前端调用
<li> <lable>验证码:</lable> <input type="text" name="yzm"> <img alt="" src="/getCode" onclick="refreshCode(this);"> <script type="text/javascript"> //刷新验证码 function refreshCode(obj){ obj.src = "/getCode?time=" + new Date().getTime(); } </script> </li>
显示效果
实现验证码类
package tool; import java.awt.*; import java.awt.image.BufferedImage; import java.util.Random; public class ImageUtil { public static Object[] createImage() { Object[] obj = new Object[2]; int width = 100; // 验证码图片的高度。 int height = 30; // 验证码字符个数 int codeCount = 4; int x = 0; // 字体高度 int fontHeight; int codeY; x = width / (codeCount + 1); fontHeight = height - 2; codeY = height - 4; char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y','3', '4', '5', '6', '7', '8', '9','a','b','c','d','e','f','g','h', 'j','k','m','n','r','s','t','u','v','w','x','y'}; //定义图像buffer BufferedImage buffImg = new BufferedImage( width, height,BufferedImage.TYPE_INT_RGB); Graphics2D g = buffImg.createGraphics(); //创建一个随机数生成器类 Random random = new Random(); //将图像填充为白色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); //创建字体,字体的大小应该根据图片的高度来定。 Font font = new Font("Fixedsys", Font.PLAIN, fontHeight-5); //设置字体。 g.setFont(font); //画边框 g.setColor(Color.WHITE); g.drawRect(0, 0, width - 2, height - 2); //随机产生干扰线,使图象中的认证码不易被其它程序探测到。 g.setColor(Color.BLACK); for(int i = 0; i < 5; i++) { int xx = random.nextInt(width); int yy = random.nextInt(height); int xxl = random.nextInt(12); int yyl = random.nextInt(12); g.drawLine(xx, yy, xx + xxl, yy + yyl); } //randomCode用于保存随机产生的验证码,以便用户登录后进行验证。 StringBuffer randomCode = new StringBuffer(); int red = 0, green = 0, blue = 0; //随机产生codeCount数字的验证码。 for (int i = 0; i < codeCount; i++) { //得到随机产生的验证码数字。 String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]); //产生随机的颜色分量来构造颜色值,这样输出的每位数字的颜色值都将不同。 red = random.nextInt(255); green = random.nextInt(255); blue = random.nextInt(255); //用随机产生的颜色将验证码绘制到图像中。 g.setColor(new Color(red, green, blue)); g.drawString(strRand, (i + 1) * x, codeY-2); //将产生的四个随机数组合在一起。 randomCode.append(strRand); } obj[0] = randomCode.toString(); obj[1] = buffImg; return obj; } }
控制器调用:
package com.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.ResponseBody; import tool.ImageUtil; import javax.imageio.ImageIO; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.awt.image.BufferedImage; import java.io.OutputStream; @Controller public class GetValiadateCode { //生成验证码图片 @ResponseBody @RequestMapping(value = "/getCode", method = RequestMethod.GET) public void validateCode(HttpServletRequest request, HttpServletResponse response) throws Exception{ //第一个参数是生成的验证码,第二个参数是生成的图片 Object[] objs = ImageUtil.createImage(); //将验证码存入Session request.getSession(true).setAttribute("validateCode",objs[0]); //将图片输出给浏览器 BufferedImage image = (BufferedImage) objs[1]; // 禁止图像缓存。 response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); response.setContentType("image/jpeg"); OutputStream os = response.getOutputStream(); ImageIO.write(image, "jpeg", os); os.flush(); } }