标签：访问 null imageio fill i++ font tin python random
编写一个JSP页面，实现统计该页面被访问的次数
定义一个全局变量counter 用application对象的属性存储
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>统计页面访问次数</title>
</head>
<body>
<%
int counter = 1;
if(application.getAttribute("counter") != null){
counter = ((Integer) application.getAttribute("counter")).intValue()+1;
}
out.print("访问量："+counter+"<br/>");
application.setAttribute("counter", counter);
%>
</body>
</html>
编写绘制验证码图片的JSP
Random设置随机数 Graphics new一个图 设置背景色 字体色和输出数字
<body>
<p>
<%
String s="";
int intCount = 0;
intCount = (new Random()).nextInt(9999);
if(intCount < 1000){
intCount += 1000;
}
s = intCount + "";
session.setAttribute("validateCode",s);
response.setContentType("image/jpeg");
BufferedImage image = new BufferedImage(35,14,BufferedImage.TYPE_INT_RGB);
Graphics gra = image.getGraphics();
gra.setColor(Color.yellow);
gra.fillRect(1, 1, 33, 12);
gra.setColor(Color.black);
gra.setFont(new Font("宋体",Font.PLAIN,12));
char c;
for(int i=0;i<4;i++){
c = s.charAt(i);
gra.drawString(c+" ", i*7+4, 11);
}
gra.dispose();
try{
ImageIO.write(image,"jpeg",response.getOutputStream());
}catch (Exception e){
}
out.clear();
out = pageContext.pushBody();
%>
</body>
标签：访问 null imageio fill i++ font tin python random
原文地址：http://www.cnblogs.com/bingo2-here/p/6083515.html
