Determining Users without login page?

Question

I need some direction on a task I need to accomplish - any help or input would greatly be
appreciated.
Big Picture
I have an application that three groups are going to be using. Each group uses the same
database connection but use different tables in database.
Example:
Group1_user
GROUP2_user
GROUP3_user
Right now the table names are hardcoded. What I need to eventually accomplish is passing
the 'GROUP1' name as a variable - so when a user from Group 1 accesses the application all the
data is from the prefix GROUP1.
Trying to make the application as dynamic as possible.
Right now
I need a way to determine which group is accessing the application without using a login
page.
If user x.xx.xxx.xxx:8080/Group1/index.html is entered verses x.xx.xxx.xxx:8080/Group2/index.html
I hope you can understand this situation and offer me some resources/advice - thanks.
Crystal

Answer 1

I am able to parse the name out by how can I set that to a string and pass it to other pages now?
String[] getDiv = userURL.split("/");
int cnt = getDiv.length;
     for(int i=0;i<cnt;i++){
          idVar = getDiv[1]; // this doesnt work        
          out.println("<b>" + getDiv[1] + "</b>" );
                     }