import java.util.regex.*;
 
class Main
{
  public static void main (String[] args) throws java.lang.Exception
  {
    Pattern p = Pattern.compile("/[^/]+\\.(.*)");
    String[] tests = { "/var/www.dir/file.tar.gz", "/var/www.dir/file.exe" };
    for (String s : tests) {
	    String lastPart = s.substring(s.lastIndexOf("/"));
	    String file = s.substring(s.lastIndexOf("/"));
	    String extension = file.substring(file.indexOf(".")); // .tar.gz
	    System.out.println(extension);
    }
  }
}

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