How do I determine the Client’s browser type and version?

The

user-agent

header can be used to determine the browser type. Be aware that the format of this header is not standardized, and the original value can get lost if the request arrives via proxy. There are numerous websites that list user-agent values for various browsers.

Here’s a simple example:

public void checkBrowserType (HttpServletRequest req)
{
   String s = req.getHeader("user-agent");
   if (s == null)
      return;
   if (s.indexOf("MSIE") > -1)
      System.out.println("using Internet Explorer");
   else if (s.indexOf("Netscape") > -1)
      System.out.println("using Netscape");
   // etc ...	
}