The Java EE 5 Tutorial

The Example JSP Pages

To illustrate JSP technology, this chapter rewrites each servlet in the Duke’s Bookstore application introduced in The Example Servlets as a JSP page (see Table 5–1).

Table 5–1 Duke’s Bookstore Example JSP Pages


JSP Pages 

Enter the bookstore. 


Create the bookstore banner. 


Browse the books offered for sale. 


Add a book to the shopping cart. 

bookcatalog.jsp and bookdetails.jsp

Get detailed information on a specific book. 


Display the shopping cart. 


Remove one or more books from the shopping cart. 


Buy the books in the shopping cart. 


Receive an acknowledgment for the purchase. 


The data for the bookstore application is still maintained in a database and is accessed through tut-install/javaeetutorial5/examples/web/bookstore2/src/java/com/sun/bookstore2/database/ However, the JSP pages access BookDBAO through the JavaBeans component tut-install/javaeetutorial5/examples/web/bookstore2/src/java/com/sun/bookstore2/database/ This class allows the JSP pages to use JSP elements designed to work with JavaBeans components (see JavaBeans Component Design Conventions).

The implementation of the database bean follows. The bean has two instance variables: the current book and the data access object.

package database;
public class BookDB {
    private String bookId = "0";
    private BookDBAO database = null;

    public BookDB () throws Exception {
    public void setBookId(String bookId) {
        this.bookId = bookId;
    public void setDatabase(BookDAO database) {
        this.database = database;
    public Book getBook()
         throws Exception {
        return (Book)database.getBook(bookId);

This version of the Duke’s Bookstore application is organized along the Model-View-Controller (MVC) architecture. The MVC architecture is a widely used architectural approach for interactive applications that distributes functionality among application objects so as to minimize the degree of coupling between the objects. To achieve this, it divides applications into three layers: model, view, and controller. Each layer handles specific tasks and has responsibilities to the other layers:

Note –

When employed in a web application, the MVC architecture is often referred to as a Model-2 architecture. The bookstore example discussed in Chapter 4, Java Servlet Technology, which intermixes presentation and business logic, follows what is known as a Model-1 architecture. The Model-2 architecture is the recommended approach to designing web applications.

In addition, this version of the application uses several custom tags from the JavaServer Pages Standard Tag Library (JSTL), described in Chapter 7, JavaServer Pages Standard Tag Library:

Custom tags are the preferred mechanism for performing a wide variety of dynamic processing tasks, including accessing databases, using enterprise services such as email and directories, and implementing flow control. In earlier versions of JSP technology, such tasks were performed with JavaBeans components in conjunction with scripting elements (discussed in Chapter 9, Scripting in JSP Pages). Although still available in JSP 2.0 technology, scripting elements tend to make JSP pages more difficult to maintain because they mix presentation and logic, something that is discouraged in page design. Custom tags are introduced in Using Custom Tags and described in detail in Chapter 8, Custom Tags in JSP Pages.

Finally, this version of the example contains an applet to generate a dynamic digital clock in the banner. See Including an Applet for a description of the JSP element that generates HTML for downloading the applet.

    To deploy and run the application using NetBeans IDE, follow these steps:

  1. Perform all the operations described in Accessing Databases from Web Applications.

  2. In NetBeans IDE, select File->Open Project.

  3. In the Open Project dialog, navigate to:

  4. Select the bookstore2 folder.

  5. Select the Open as Main Project check box and the Open Required Projects check box.

  6. Click Open Project.

  7. In the Projects tab, right-click the bookstore2 project, and select Undeploy and Deploy.

  8. To run the application, open the bookstore URL http://localhost:8080/bookstore2/books/bookstore.

    To deploy and run the application using Ant, follow these steps:

  1. In a terminal window, go to tut-install/javaeetutorial5/examples/web/bookstore2/.

  2. Type ant. This command will spawn any necessary compilations, copy files to the tut-install/javaeetutorial5/examples/web/bookstore2/build/ directory, and create a WAR file and copy it to the tut-install/javaeetutorial5/examples/web/bookstore2/dist/ directory.

  3. Start the Application Server.

  4. Perform all the operations described in Creating a Data Source in the Application Server.

  5. To deploy the example, type ant deploy. The deploy target outputs a URL for running the application. Ignore this URL, and instead use the one shown in the next step.

  6. To run the application, open the bookstore URL http://localhost:8080/bookstore2/books/bookstore.

To learn how to configure the example, refer to the deployment descriptor (the web.xml file), which includes the following configurations:

Figure 5–2 shows the bookcatalog.jsp page from the Duke’s Bookstore application. This page displays a list of all the books that are available for purchase.

Figure 5–2 Book Catalog

Screen capture of Duke's Bookstore book catalog, with
titles, authors, prices, and "Add to Cart" links. Titles are links to book

See Troubleshooting Duke's Bookstore Database Problems for help with diagnosing common problems related to the database server. If the messages in your pages appear as strings of the form ??? Key ???, the likely cause is that you have not provided the correct resource bundle base name as a context parameter.