javax.swing What is JFC and Swing? JFC is a loose collection of APIs for client-side graphics, graphical user interfaces (GUIs), and other related tasks.  It specifically contains: Abstract Window Toolkit (AWT 1.1 and beyond) Swing Components ("Swing") Java2D Accessibility Drag and Drop Swing is a set of mostly light-weight components built on top of AWT.  It offers a multitude of components missing in AWT, plus it has an impressive infrastructure to build real, industrial-strength GUIs.  Thus, it does not replace, but rather extends the AWT in several significant ways: Replacement of AWT's heavy-weight components with light-weight components (except JApplet, JFrame, JWindow, and JDialog) Transparent backgrounds Pluggable look and feels (plafs) Full suite of GUI building blocks Buttons, Labels, Lists, and Menus that can accommodate graphics as well as text True pop-up windows and tooltips Dockable toolbars and menu bars Default Dialog boxes and Color and File Chooser dialog boxes Tree, Table, and Tabbed Panes MDI support Swing Component Architecture Model-View-Controller (MVC) architecture Model Responsible for maintaining data and firing events to registered Views when the model changes View Responsible for providing a visual representation of some portion of the model's data Controller Handle events for the views Swing actually uses a variation of the MVC architecture by combining the View and Controller into an UI Delegate that's responsible for handling events and drawing a visual representation of the Model It is Swing's adoption of the MVC architecture that enables plaf to be easily implemented -- Models don't depend on Views or Controllers, so just plug a different View/Controller to a model to change the look and feel Practical Usage of Swing Don't mix heavy weight AWT components with light weight Swing components Swing components are not thread-safe, so only modify the model's data through the event dispatch thread Add components to the content panes and not to the containers themselves Live Example 2 Build a Java version of Windows® WordPad Additionally, it can change its look and feel on the fly JWordPad.java

javax.servlet What's a Servlet? Servlets are server-side Java applications Most popularly, they are run on web servers to dynamically generate HTML pages Analogy: Applets run in web browsers.  Servelets run in web servers. Java Servlet API is a standard Java extension Lots of web servers support the Servlet API Apache Jigsaw Why use Servlets? Better performance CGI scripts usually use one process per invocation; better implementations use processes more efficiently, but Java handles concurrency much better Better technology ASP (Active Server Pages) offers comparable features but is a hodge-podge solution from the early 90's that 's not easily portable Better bargain Servlet extensions into web servers are usually free! Quick Introduction Client Interaction When a servlet accepts a call from a client, it receives two objects: A ServletRequest, which encapsulates the communication from the client to the server.  A ServletResponse, which encapsulates the communication from the servlet back to the client. ServletRequest and ServletResponse are interfaces defined by the javax.servlet package The ServletRequest interface allows the servlet access to: Information such as the names of the parameters passed in by the client, the protocol (scheme) being used by the client, and the names of the remote host that made the request and the server that received it.  The input stream, ServletInputStream. Servlets use the input stream to get data from clients that use application protocols such as the HTTP POST and PUT methods. Interfaces that extend ServletRequest interface allow the servlet to retrieve more protocol-specific data. For example, the HttpServletRequestinterface contains methods for accessing HTTP-specific header information.  The ServletResponse interface gives the servlet methods for replying to the client. It: Allows the servlet to set the content length and MIME type of the reply  Provides an output stream, ServletOutputStream, and a Writer through which the servlet can send the reply data Interfaces that extend the ServletResponse interface give the servlet more protocol-specific capabilities. For example, the HttpServletResponseinterface contains methods that allow the servlet to manipulate HTTP-specific header information Live Example 3

public class SimpleServlet extends HttpServlet { 
	/**
	 * Handle the HTTP GET method by building a simple web page.
	 */
	public void doGet (HttpServletRequest request,
			   HttpServletResponse response)
		throws ServletException, IOException {
	PrintWriter out;
	String title = "Simple Servlet Output";

	// set content type and other response header fields first
	response.setContentType("text/html");

	// then write the data of the response
	out = response.getWriter();

	out.println("<HTML><HEAD><TITLE>");
	out.println(title);
	out.println("</TITLE></HEAD><BODY>");
	out.println("<H1>" + title + "</H1>");
	out.println("<P>This is output from SimpleServlet.");
	out.println("</BODY></HTML>");
	out.close();
    }
}