Requesting More - Java

Now that the basics are done with, it's time to begin applyingthat theory to Web development. This week, The JSP Files investigates theJSP Request object, and demonstrates how it can be used to process formdata. Learn about JSP's array variables, find out what chocolate chipcookies and couch potatoes have in common, and explore a very unusualpharmacy.

TABLE OF CONTENTS:

By: Vikram Vaswani, (c) Melonfire

Poor Best

Rating:

/ 6

March 07, 2001

print this article

SEARCH DEV SHED

TOOLS YOU CAN USE

The Request object also comes with a bunch of other useful methods - the following example demonstrates some of them

<html>
<head>
<basefont face="Arial">
</head>
<body>
<table border="1" cellspacing="5" cellpadding="5">
<tr>
<td><b>Variable</b></td>
<td><b>Value</b></td>
</tr>
<tr>
<td>Request protocol</td>
<td>
<%
// protocol
out.println(request.getProtocol());
%>
</td>
</tr>
<tr>
<td>Hostname</td>
<td>
<%
// server name
out.println(request.getServerName());
%>
</td>
</tr>
<tr>
<td>Port</td>
<td>
<%
// server port
out.println(request.getServerPort());
%>
</td>
</tr>
<tr>
<td>Remote username</td>
<td>
<%
// username if using HTTP authentication
// null if no authentication
out.println(request.getRemoteUser());
%>
</td>
</tr>
<tr>
<td>Remote address</td>
<td>
<%
// get IP address of client
out.println(request.getRemoteAddr());
%>
</td>
</tr>
<tr>
<td>Client browser</td>
<td>
<%
// client browser identification
out.println(request.getHeader("User-Agent"));
%>
</td>
</tr>
</table>
</body>
</html>

And when you view the file in your browser, you'll probably see something like this:


Variable  Value
Request protocol HTTP/1.0Hostname localhostPort 80Remote username nullRemote address 192.168.0.143Client browser  Mozilla/4.0 (compatible; MSIE 5.5; Windows 95)

All these variables come in handy if you need to make decisions on the basis of remote variables - as the following example demonstrates:

<%
String browser = request.getHeader("User-Agent");if(browser.indexOf("MSIE") >= 0){ // IE-specific code}else if(browser.indexOf("Mozilla") >= 0){ // Mozilla-specific code}else{ // any other browser}%>

Note our usage of the indexOf() method - you may remember this from previous articles in this series.

Next: Taking Some Medication >>