/* * Copyright (c) 2000 David Flanagan.  All rights reserved. * This code is from the book Java Examples in a Nutshell, 2nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book (recommended), * visit http://www.davidflanagan.com/javaexamples2. */package com.davidflanagan.examples.servlet;import javax.servlet.http.*;/** * This class is a simple non-visual JavaBean that defines properties that can * be used from a JSP page with the <jsp:useBean>, <jsp:setProperty> and * <jsp:getProperty> tags.  These JSP tags allow significant chunks of Java * code to be taken out of JSP pages and placed in Java files, where they are * easier to read, edit, and maintain.  This example only defines a few * trivial properties, but the class could do much more. *  * This class is instantiated by portal.jsp and is bound in the Session object. * Therefore, it implements HttpSessionBindingListener so that it is notified  * when the session is terminated (when the user logs out or the session * times out). **/public class UserBean implements HttpSessionBindingListener {    String username;              // The name of the user we represent    String favorite = colors[0];  // The user's favorite color, with a default    static final String[] colors = { "gray", "lightblue", "pink", "yellow" };    // These are the getter and setter methods for the userName property    // In a real program, setUserName() would probably look up information     // about the user in a database of some kind.    public String getUserName() { return username; }    public void setUserName(String username) { this.username = username; }    // These are the getter and setter methods for the favoriteColor property    public String getFavoriteColor() { return favorite; }    public void setFavoriteColor(String favorite) { this.favorite = favorite; }    // Return a list of colors the user is allowed to choose from    public String[] getColorChoices() { return colors; }    // This is a getter method for the "customContent" property.  In a more    // sophisticated example, this method might query a database and return    // current news clippings or stock quotes for the user.  Not here, though.    public String getCustomContent() {	return "Your name backwards is: <tt>" + 	    new StringBuffer(username).reverse() + "</tt>";    }    // This method implements HttpSessionBindingListener.  If an instance of    // this class is bound in a HttpSession object, then this method will    // be invoked when the instance becomes unbound, which typically happens    // when the session is invalidated because the user logged out or    // was inactive for too long.  In a real example, this method would    // probably save information about the user to a file or database.    public void valueUnbound(HttpSessionBindingEvent e) {	System.out.println(username + " logged out or timed out." + 			   " Favorite color: " + favorite);    }    // Part of HttpSessionBindingListener; we don't care about it here    public void valueBound(HttpSessionBindingEvent e) {}}