5577l1.txt 0100664 0002046 0000330 00000005503 07371542435 011462 0 ustar jill ljedit 5577l1
Listing 1. BookBean.java, the bean class for our entity bean. This is
the code that actually does the work. In most simple cases (as with
this example), the bean class does little more than implement methods
to retrieve and modify instance variables.
package il.co.lerner.book;
import javax.ejb.EntityBean;
import javax.ejb.EntityContext;
import java.rmi.RemoteException;
import il.co.lerner.book.BookPK;
/**
BookBean, the bean class for our entity bean. Each instance of
BookBean represents a different book, which is represented in the
back-end database by a single row in a database table.
*/
public class BookBean implements EntityBean
{
EntityContext ctx;
public int id;
public String title;
public String author;
public String publisher;
public double usDollarPrice;
/* Each time create() is invoked on the home interface,
ejbCreate() is invoked on our object with the same
arguments. */
public BookPK ejbCreate(int newId, String newTitle,
String newAuthor, String newPublisher,
double newUsDollarPrice)
{
// Assign our instance variables based on the arguments
id = newId;
title = newTitle;
author = newAuthor;
publisher = newPublisher;
usDollarPrice = newUsDollarPrice;
// Let the system handle the rest!
return null;
}
/* After ejbCreate() is invoked, the system executes
ejbPostCreate(), once again with the same arguments as create()
and ejbCreate(). Our bean is simple enough that it doesn't
need to do anything in ejbPostCreate(). */
public void ejbPostCreate(int newId, String title,
String author, String publisher,
double usDollarPrice) { }
/* We need to write one "setter" and one "getter" for each public
instance variable. */
public int getId() { return id; }
public void setId(int newId) { id = newId; }
public String getTitle() { return title; }
public void setTitle(String newTitle) { title = newTitle; }
public String getAuthor() { return author; }
public void setAuthor(String newAuthor) { author = newAuthor; }
public String getPublisher() { return publisher; }
public void setPublisher(String newPublisher)
{
publisher = newPublisher;
}
public double getUsDollarPrice() { return usDollarPrice; }
public void setUsDollarPrice(double newUsDollarPrice)
{
usDollarPrice = newUsDollarPrice;
}
/* We must implement the following methods */
public void setEntityContext(EntityContext ctx) { this.ctx = ctx; }
public void unsetEntityContext() { ctx = null; }
/* We must implement the following methods, but will leave them
without procedure bodies. */
public void ejbActivate() { }
public void ejbPassivate() { }
public void ejbLoad() { }
public void ejbStore() { }
public void ejbRemove() { }
}
5577l2.txt 0100664 0002046 0000330 00000002017 07371542435 011460 0 ustar jill ljedit 5577l2
Listing 2. Source code for our remote interface, Book.java. This class
mirrors the public methods defined by our BookBean class.
package il.co.lerner.book;
import javax.ejb.EJBObject;
import java.rmi.RemoteException;
/* The remote interface for the Book entity bean. We declare a method
for each method in the BookBean class, with an identical signature. */
public interface Book extends EJBObject
{
public int getId() throws RemoteException;
public void setId(int newId) throws RemoteException;
public String getTitle() throws RemoteException;
public void setTitle(String newTitle) throws RemoteException;
public String getAuthor() throws RemoteException;
public void setAuthor(String newAuthor) throws RemoteException;
public String getPublisher() throws RemoteException;
public void setPublisher(String newPublisher) throws RemoteException;
public double getUsDollarPrice() throws RemoteException;
public void setUsDollarPrice(double newDollarPrice)
throws RemoteException;
}
5577l3.txt 0100664 0002046 0000330 00000002161 07403777123 011461 0 ustar jill ljedit 5577l3
Listing 3. Defining a Home Interface
package il.co.lerner.book;
import javax.ejb.EJBHome;
import javax.ejb.CreateException;
import javax.ejb.FinderException;
import java.rmi.RemoteException;
import java.util.Collection;
/* This class defines the home interface for our Book entity bean. */
public interface BookHome extends EJBHome
{
/* Create a new instance of Book */
public Book create(int newId, String newTitle,
String newAuthor, String newPublisher,
double newUsDollarPrice)
throws RemoteException, CreateException;
/* Find a Book with the specified ID. The EJB container
implements this method for us automatically. */
public Book findByPrimaryKey (int id)
throws RemoteException, FinderException;
/* Return a Collection of books that matches an author name. This
method is implemented automatically by the EJB container. */
public Collection findByAuthor (String authorName)
throws RemoteException, FinderException;
/* Return all of the Book objects in the database */
public Collection findAll() throws RemoteException, FinderException;
}
5577l4.txt 0100664 0002046 0000330 00000001120 07371542435 011454 0 ustar jill ljedit 5577l4
Listing 4. BookPK.java, the Primary Key Class for Our Entity Bean
package il.co.lerner.book;
import java.io.Serializable;
public class BookPK implements java.io.Serializable
{
public int id;
public BookPK () { }
public BookPK(int value)
{
id = value;
}
public boolean equals(Object obj)
{
if (obj == null || !(obj instanceof BookPK))
return false;
if (((BookPK)obj).id == id)
return true;
return false;
}
public int hashCode ()
{
return id;
}
public String toString()
{
return String.valueOf(id);
}
}
5577l5.txt 0100664 0002046 0000330 00000001734 07371542435 011470 0 ustar jill ljedit 5577l5
Listing 5. ejb-jar.xml, the Deployment Descriptor for Our Entity Bean
ATF Book Bean
ATF Book
Models a book
Book
il.co.lerner.book.BookHome
il.co.lerner.book.Book
il.co.lerner.book.BookBean
Container
False
il.co.lerner.book.BookPK
id
author
title
publisher
usDollarPrice
5577l6.txt 0100664 0002046 0000330 00000004612 07371542435 011467 0 ustar jill ljedit 5577l6
Listing 6. UseBook.java
package il.co.lerner.book;
/* Import our entity bean */
import il.co.lerner.book.Book;
import il.co.lerner.book.BookHome;
/* Import the RMI and JDNI items we need */
import javax.rmi.PortableRemoteObject;
import javax.naming.InitialContext;
import java.util.Properties;
import java.util.Collection;
import java.util.Iterator;
import java.io.FileInputStream;
/* This application demonstrates how we can INSERT, UPDATE, and SELECT
information from a database table using EJB's objects instead of
SQL. */
public class UseBook
{
public static void main(String[] args)
{
final int testPrimaryKey = 11;
try
{
System.out.println("(UseBook) About to get an InitialContext");
// Get a naming context
InitialContext jndiContext = new InitialContext();
System.out.println("(UseBook) About to invoke jndiContext.lookup()");
// Get a reference to a Book Bean
Object ref = jndiContext.lookup("Book");
System.out.println("(UseBook) About to use the reference from JNDI");
// Get a reference from this to the Bean's Home interface
BookHome home =
(BookHome) PortableRemoteObject.narrow (ref,
BookHome.class);
System.out.println("(UseBook) About to create a new book");
Book book = home.create(testPrimaryKey, "Book title",
"AuthorFirst AuthorLast",
"PublisherName", 10.50);
System.out.println("(UseBook) Successfully added!");
String title = book.getTitle();
String author = book.getAuthor();
System.out.println("(UseBook) The title is '"+ title + "' and the author is '" + author + "'");
// Now let's change the information
book.setTitle("New title");
book.setAuthor("New author");
// Let's retrieve and double-check the information
String checkTitle = book.getTitle();
String checkAuthor = book.getAuthor();
System.out.println("(UseBook) After changes, the title is '"+ checkTitle + "' and the author is '" + checkAuthor + "'");
// Now let's get all of the books
Collection bookCollection = home.findAll();
Iterator bookIterator = bookCollection.iterator();
while (bookIterator.hasNext())
{
Book aBook = (Book) bookIterator.next();
System.out.println("(UseBook) Retrieved book has id '"+ aBook.getId() + "', title '"+ aBook.getTitle() + "' and an author of '" + aBook.getAuthor() + "'");
}
}
catch(Exception e)
{
System.out.println(e.toString());
}
}
}
5577l7.txt 0100664 0002046 0000330 00000012561 07371542435 011472 0 ustar jill ljedit 5577l7
Listing 7. build.xml