checkcode.jsp
<%@ page contentType="image/jpeg"
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"%>
<%!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);
}%>
<%
out.clear();//è¿å¥é对resinæå¡å¨ï¼å¦ææ¯tomacatå¯ä»¥ä¸è¦è¿å¥
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
int width = 60, height = 20;
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
Random random = new Random();
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
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);
}
String sRand = "";
for (int i = 0; i < 4; i++) {
String rand = String.valueOf(random.nextInt(10));
sRand += rand;
g.setColor(new Color(20 + random.nextInt(110), 20 + random
.nextInt(110), 20 + random.nextInt(110)));
g.drawString(rand, 13 * i + 6, 16);
}
//å°è®¤è¯ç åå¥SESSION
session.setAttribute("checkcode", sRand);
g.dispose();
ImageIO.write(image, "JPEG", response.getOutputStream());
response.getOutputStream().close();
out.clear();
out = pageContext.pushBody();
%>
login.jsp
<div class="code"> 验证码:<span><input maxlength="20" size="13" name="checkcode" class="code_input" id="checkcode" onKeyUp="this.value=this.value.replace(/\D*(\d*\.?\d{0,2})\d*\D*/g,'$1')"></span>
<span><a href="#">
<img src="${ctx}/common/checkcode.jsp" width="60" height="20" border="0" class="code_img" id="checkcode_img" onclick="refreshCode();" /></a></span>
</div>
javascript:
function refreshCode(){ $("#checkcode_img").attr("src","${ctx}/common/checkcode.jsp?random="+Math.random()); }