简单的 jsp验证码 代码！
第一个网页 ----------------------------------------a.html----------------------------------------------
<html>
<body>
<form method=post action="c.jsp">
<input type=text name=input maxlength=4>
<img border=0 src="b.jsp">
<input type="submit" value="submit">
</form>
</body>
</html>
第二个网页 --------------------- b.jsp -----------------------------------------------------
<%@ page contentType="image/JPEG"
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"
pageEncoding="GBK"%>
<%!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);
}%>
<%
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 < 100; 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++) {
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);
}
session.setAttribute("code", sRand);
g.dispose();
ImageIO.write(image, "JPEG", response.getOutputStream());
%>
第三个网页 -----------------------------c.jsp----------------------------------------------
<%@ page
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"%>
<%@ page import="java.io.OutputStream"%>
<%!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);
}%>
<%
try {
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
int width = 60, height = 16;
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
OutputStream os = response.getOutputStream();
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, 14);
}
session.setAttribute("code", sRand);
g.dispose();
ImageIO.write(image, "JPEG", os);
os.flush();
os.close();
os = null;
response.flushBuffer();
out.clear();
out = pageContext.pushBody();
} catch (IllegalStateException e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
%>
[解决办法]
jf!!!!!!!!!!!!!!!!!!!!!!!!!
[解决办法]
lz
你都没说什么问题啊
[解决办法]
不知道楼主要干什么，提交到了一个新生成的验证码页面？
[解决办法]
估计是大概在刷新的时候还是那些验证码
像问为什么没变的原因吧
[解决办法]
顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！
[解决办法]
顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！顶！
[解决办法]
顶....
