1.
<%@ page pageEncoding="UTF-8"%>
<%@ page import="java.io.*"%>
<%@ page import="java.util.*"%>
<%@ page import="java.math.*"%>
<html>
<head><title>网站计数器</title></head>
<body>
<%!
BigInteger count = null ; //定义一个
%>
<%!
public BigInteger load(File file){
BigInteger count = null ; // 接收数据
try{ //判断是否有存储数据的文件
if(file.exists()){
Scanner scan = new Scanner(new FileInputStream(file)) ;
if(scan.hasNext()){
count = new BigInteger(scan.next()) ;//将内容放到BigInteger类中
}
scan.close() ;
} else {
count = new BigInteger("0") ; // 从0开始
save(file,count) ; // 保存为一个新的文件
}
}catch(Exception e){
e.printStackTrace() ;
}
return count ;
}
public void save(File file,BigInteger count){ //保存计数文件
try{
PrintStream ps = null ;
ps = new PrintStream(new FileOutputStream(file)) ;
ps.println(count) ;
ps.close() ;
}catch(Exception e){
e.printStackTrace() ;
}
}
%>
<%
String fileName = this.getServletContext().getRealPath("/") + "count.txt"; // 保存所有的计数结果
File file = new File(fileName) ;
if(session.isNew()){ //同一次会话不重复计数
synchronized(this){
count = load(file) ;
count = count.add(new BigInteger("1")) ; // 再原本的基础上增加1。
save(file,count) ;
}
}
%>
<h2>您是第<%=count==null?0:count%>位访客！</h2>
</body>
</html> 2.
<%@ page language="java"
contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
</head>
<body>
<%
String username = "";
String password = "";
// 获取cookie
Cookie[] cookies = request.getCookies();
// 如果为空，则停留在该页面
if(cookies == null){
return ;
// 不为空则获取用户名和密码
}else{
for(int i = 0; i < cookies.length; i++){
if("username".equals(cookies[i].getName())){
username = cookies[i].getValue();
}
if("password".equals(cookies[i].getName())){
password = cookies[i].getValue();
}
}
// 验证用户名和密码
if("admin".equals(username) && "123".equals(password)){
session.setAttribute("username", username);
session.setAttribute("password", password);
}
}
%>
<form action="test" method="post">
用户名：<input type="text" name="username"/><br/>
密 码：<input type="password" name="password" /><br />
<input type="submit" value="登陆" />
</form>
</body>
</html>3.
Index.jsp
<%@ page pageEncoding="utf-8"%>
<html>
<body>
<iframe src="content.jsp" name="content" width="100%" height="80%"></iframe>
<form action="addinfo.jsp" target="content" id="chatform" method="post">
昵称：<input type="text" name="nicheng" id="nicheng">
发言：<input type="text" name="info" id="info">
<input type="button" value="确定" onclick="check()">
</form>
<script>
function check(){
var nicheng=document.getElementById("nicheng").value;
var info=document.getElementById("info").value;
if(nicheng==''||info==''){
alert("昵称或留言内容不能为空");
}
else{
document.getElementById("chatform").submit();
}
}
</script>
</body>
</html>Content.jsp
<%@ page pageEncoding="utf-8" import="java.util.*"%>
<%@ page import="org.apache.commons.lang3.StringUtils"%>
<html>
<head>
<meta http-equiv="refresh" content="10">
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
</head>
<body>
<%
request.setCharacterEncoding("UTF-8");
%>
<%=application.getAttribute("infoList1") %>
</body>
</html>Addinfo.jsp
<%@ page pageEncoding="utf-8" import="java.util.*,java.text.*"%>
<%@ page import="org.apache.commons.lang3.StringUtils"%>
<html>
<body>
<%
request.setCharacterEncoding("UTF-8");
String nicheng=request.getParameter("nicheng");
String info=request.getParameter("info");
String time=new SimpleDateFormat("yy-MM-dd kk:mm:ss").format(new Date());//当前时间
List<String> infoList=new ArrayList<String>();
String s=(String)application.getAttribute("infoList1");
if(s==null){
//第一次存储信息
s="";
}
else{
String[] a=s.split("<br>");
int b=a.length;
if(b==30){
//够30条
s="";
}
infoList.add(nicheng+"在"+time+"说:"+info+"<br>");
s=s+StringUtils.strip(infoList.toString(),"[]");
//添加
}
application.setAttribute("infoList1", s);
response.sendRedirect("content.jsp");
//重定向到content.jsp
%>
</body>
</html>- 否
GetNumer.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
</head>
<body>
程序随机产生了一个0-100间的整数，请猜一猜<br>
<%
int n=(int)(Math.random()*100)+1;
session.setAttribute("save", new Integer(n));
%>
<form action="caishu.jsp" method="post">
<input type="text" name="t1"/>
<input type="submit" value="guess"/>
</form>
</body>
</html>Caishu.jsp
<%@ page pageEncoding="UTF-8" %>
<html>
<body>
<body>
程序随机产生了一个0-100间的整数，请猜一猜<br>
<form action="caishu.jsp" method="get">
<input type="text" name="t1"/>
<input type="submit" value="guess"/>
</form>
<%
String t1=request.getParameter("t1");
Integer integer=(Integer)session.getAttribute("save");
int realnumber=integer.intValue();
if(t1!=null){
int t=Integer.parseInt(t1);
if(t==realnumber){
out.print("right,<a href='getNumber.jsp'>再来一次</a>");
}
else if(t<realnumber){
out.print("too small");
out.println(realnumber);
}
else{
out.print("too large");
out.println(realnumber);
}
}
%>
</body>
</html>
