title: jsp to view log file (like "web tail -f")
body: <p>How would you implement a jsp site containing a text area which shows a log file on the (tomcat) server and refreshes automatically.</p>
  
  <p>I think the refresh is simple to poll to the server using setTimeout and sending an ajax request. But the problem is how to monitor the file on the server (it is a Log4J Logfile - maybe I can use an own appender?) for changes and sending only the changed lines when the ajax request arrives?</p>
  
  <p>I've no idea how to detect the changed lines in the log...</p>