Arron Zhang

package arron;
import javax.servlet.http.HttpSessionListener;
import javax.servlet.http.HttpSessionEvent;
public class SessionCount implements HttpSessionListener {

private static int activeSessions = 0;
public static int getActiveSessions() {
return activeSessions;
}
public void sessionCreated(HttpSessionEvent e) {
activeSessions++;
}

public void sessionDestroyed(HttpSessionEvent e) {
if(activeSessions > 0) activeSessions--;
}
}

try this,
<form name="form1" action="">
<input type="hidden" name="a" value="">
</input>
<script language="javascript">
//set value of "a"
//set action of "form1"
form1.submit()
</script>

Help me!

I got it.
In my filter,write such statment:
HttpServletRequest hrequest=(HttpServletRequest)request;
then,
String url=hrequest.getRequestURI();

Sorry,
I want go get the URL in Filter.
There's no method getRequestURL() in ServletRequest.

example:
if user input:
http://www.xxxx.com/???/???.htm
How can I get "???/???.htm" in JSP

CLASSPATH=.;E:\j2sdkee1.4\lib\j2ee.jar;E:\Sun_studio_sdk\j2sdk1.4.1\lib\tools.jar

System: win2k professional
environment variable:
JAVA_HOME=E:\sun_studio\j2sdk1.4.1
J2EE_HOME=E:\j2sdkee1.4
ANT_HOME=F:\ANT1.5.1
path=%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;E:\Sun_studio_sdk\j2sdk1.4.1\bin;E:\j2sdkee1.4\bin;E:\Mysql\bin

I installed the J2EE_SDK on my computer,but it can't run with command line.
If use "j2ee -verbose",there's an exception:
java.lang.NoClassDefFoundError: Files\Common
If use the Start_J2EE in start_menu,it run successfully.

You can use the deploytool which is an additional tool in J2EE_SDK to deploy EJB on J2EE server,or you have to use another server such as Weblogic server.

I see.
Thanks.

I test the length of String from 32k to 15M(the size of memory on my computer is 384M)
the length can be any digit less than 15M,
when the length is 15M,exception:
Exception in thread "main" java.lang.OutOfMemoryError

maximum length of String = 32k ?

but when I use getString(int i)
the program run successfully!

friends,
when I use getString(String columnName) in Mysql,
Exception:
java.sql.SQLException: Column 'User' not found.
why？