Javaweb 实现一个简单留言板

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
    
<%
	String temp = new String();
	temp = (String) application.getAttribute("num");
	if (temp == null) {
		application.setAttribute("num", "0");
	}
%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
<style>
	p1{
		color:red;
	}
</style>
</head>
<script type="text/javascript">
	function checkuser(){
	
		var ch=true;
		var t1=document.getElementById("user").value;
		if(t1=="")
		{
			alert("用户名为空");
			ch=false;
		}
		return ch ;
	}
	function check(){
	        if(checkuser())
	        	return true ;
	        else 
	        	return false;
	}
</script>
<body>
	<form  id="form"  method="get" action="NewFile1.jsp" onsubmit="return check()" >
		<table >
			<tr>
			<td align="right"> 用户:</td>
			<td> <input type="text" name="user" id="user" onchange="checkuser()" style="width:170px;"/></td>
			</tr>
			<tr>
			<td align="right"> 留言:</td>
			<td> <input type="test" id="liuyan" name="liuyan"  style="width:170px;"/></td>
			</tr>
			<tr>
			<td colspan="2" >
			<input type="submit" name="bt1"  value="提交"/>
			</td>
			</tr>
		</table>
	</form>
</body>

</html>

<%@ page language="java" import="java.util.*" 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>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
		<%request.setCharacterEncoding("utf-8"); %>
		<%
			int n;
			String temp1 = new String();
			String temp2 = new String();
			String temp3 = new String();
			String temp =new String();
			temp1 = request.getParameter("user");
			temp2 = request.getParameter("liuyan");
			temp3 =request.getRemoteAddr();

			temp = (String)application.getAttribute("num");
			n = Integer.parseInt(temp);
			n = n + 1;
			temp = temp.valueOf(n);
			application.setAttribute("num", temp);
			application.setAttribute("xingming" + temp, temp1);
			application.setAttribute("liuyan" + temp, temp2);
			application.setAttribute("ip"+temp,temp3);
		%>
		<%
				int i;
				for (i = 1; i <= n; i++) {
					temp = temp.valueOf(i);
					temp1 = (String) application.getAttribute("xingming" + temp);
					temp2 = (String) application.getAttribute("liuyan" + temp);
					temp3 =(String) application.getAttribute("ip" + temp);
		%>
		<tr>
			<td bgcolor="#CCFFCC" height="27"><b><%=temp1%>@<%=temp3%>说:
					<%=temp2%></b></td></br>
		</tr>
		<%
			}
			
		%>

</body>
</html>