Calling a Servlet Programmatically

First, identify which servlet to call by specifying a URI. This is normally a path relative to the current application. For example, if your servlet is part of an application with a context root called OfficeFrontEnd, the URL to a servlet called ShowSupplies from a browser is as follows:

http://server:port/OfficeApp/OfficeFrontEnd/servlet/ShowSupplies?name=value

You can call this servlet programmatically from another servlet in one of two ways, as described below.

• To include another servlet's output, use the include() method from the RequestDispatcher interface. This method calls a servlet by its URI and waits for it to return before continuing to process the interaction. The include() method can be called multiple times within a given servlet.

  For example:

   RequestDispatcher dispatcher =
       getServletContext().getRequestDispatcher("/ShowSupplies");
    dispatcher.include(request, response);

         

• To hand interaction control to another servlet, use the RequestDispatcher interface's forward() method with the servlet's URI as a parameter.

  This example shows a servlet using forward():

   RequestDispatcher dispatcher =
       getServletContext().getRequestDispatcher("/ShowSupplies");
    dispatcher.forward(request, response);