Sun Java System Web Server 7.0 Developer's Guide to Java Web Applications

Delivering Client Results

The final user interaction activity is to provide a response page to the client. The response page can be delivered by creating a servlet response page or JSP response page.

Creating a Servlet Response Page

Generate the output page within a servlet by writing to the output stream. The recommended generation method depends on the output type.

Always specify the output MIME type using setContentType() before any output commences, as follows


Creating a JSP Response Page

Servlets can invoke JSP files in two ways, the include() method and the forward() method.

RequestDispatcher dispatcher =
 dispatcher.include(request, response);
   ... //processing continues

Note –

You cannot use the forward() method if you have already defined a PrintWriter or ServletOutputStream object.

This example shows a JSP page using forward():

RequestDispatcher dispatcher =
 dispatcher.forward(request, response);

You identify which JSP noun to call by specifying a Universal Resource Identifier (URI). The path is a String describing a path within the ServletContext scope. You can also use the getRequestDispatcher() method in the request object that takes a String argument indicating a complete path.

Note –


RequestDispatcher dispatcher = req.getRequestDispatcher(“foo/bar”);

Note –

In the previous example getRequestDispatcher does not start with “/”. In Web Server 6.1, this syntax resulted in a URI such as /webapp/foo/bar. In Sun Java System Web Server 7.0, the URI appears as /webapp/current_servlet_path/foo/bar

For more information about JSP pages, see Chapter 5, Developing JavaServer Pages.