我准备写个jsp生成验证码的例子,在网上找了个:
hehe.jsp
<%@ page contentType="text/html;charset=GBK"
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"
pageEncoding="GBK"%>
<html>
<body>
<%!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);
}%><%
//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
int width = 60, height = 20;
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("Times New Roman", Font.PLAIN, 18));
//画边框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 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 < 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;
// 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(rand, 13 * i + 6, 16);
}
// 将认证码存入SESSION
session.setAttribute("code", sRand);
// 图象生效
g.dispose();
// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());
%> </body>
</html> validatecode.jsp
<%@ page contentType="text/html;charset=GBK"%><html>
<body>
<%@ include file="hehe.jsp"%>
<br /><br /><br /><br />
<center>
<form name="f1" action="?type=validate" method="post" >
<br />
请输入上面的验证码:<input type="text" name="t1" value="" /><br />
<input type="submit" value="提交" />
</form>
</center>
</body>
</html>两个页面单独访问都是没有问题的,但是当validatecode.jsp包含hehe.jsp时,validatecode.jsp中表单里的text和submit都不显示了,谁能指点下
hehe.jsp
<%@ page contentType="text/html;charset=GBK"
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"
pageEncoding="GBK"%>
<html>
<body>
<%!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);
}%><%
//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
int width = 60, height = 20;
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("Times New Roman", Font.PLAIN, 18));
//画边框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 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 < 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;
// 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(rand, 13 * i + 6, 16);
}
// 将认证码存入SESSION
session.setAttribute("code", sRand);
// 图象生效
g.dispose();
// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());
%> </body>
</html> validatecode.jsp
<%@ page contentType="text/html;charset=GBK"%><html>
<body>
<%@ include file="hehe.jsp"%>
<br /><br /><br /><br />
<center>
<form name="f1" action="?type=validate" method="post" >
<br />
请输入上面的验证码:<input type="text" name="t1" value="" /><br />
<input type="submit" value="提交" />
</form>
</center>
</body>
</html>两个页面单独访问都是没有问题的,但是当validatecode.jsp包含hehe.jsp时,validatecode.jsp中表单里的text和submit都不显示了,谁能指点下
ImageIO.write(image, "JPEG", response.getOutputStream()); 这句注释上之后 换成out.println("汉字内容,不加图片的");
就好用了,被包含进去validatecode.jsp里面的东西也正常显示了。
帮帮忙啊着急.
例:<html:img src="validateCode.jsp" width="50" height="20"/>
网上这方面很多的.