The complete application may provide many other objects and services. On Servlet Central, Clint Daulton offers some philosophy on how to write servlets - a kind of Zen and the Art of Servlets. It provides a large list of servlet examples and example libraries. When you download Tomcat or another servlet engine they generally come also come with a small set of examples. However, you can communicate with a servlet from any TCP client.
POST requests are generally more robust.
If your servlet does not seem to be receiving TCP parameters and requests properly, you can have the TCP client send the request to SnoopServlet. SnoopServlet displays the values of all parameters sent in your GET or POST request. Weblogic also has a SnoopServlet written in JSP called SnoopSevlet.html , BEA Systems, WebLogic Docs. Servlets do not have GUI interfaces like applets. They have an HTTP interface.