Технология Enterprise Java Beans. Часть 1

public interface CommoditiesListRemote extends EJBObject  
{
public List getAvailableCommodities()   throws RemoteException,
SQLException;
public Commodity getCommodityById(int id)   throws RemoteException, SQLException;
}

public interface CommoditiesListHome extends EJBHome
{
public CommoditiesListRemote create()   throws RemoteException, CreateException;
}

public class CommoditiesListBean implements SessionBean  
{
private static final long serialVersionUID = -8641939595462379799L;
private DataSource dataSource = null;
public List getAvailableCommodities()   throws SQLException  
	{ 
	if (dataSource == null)
	throw new SQLException("Datasource not loaded");
	Connection conn = dataSource.getConnection();
	PreparedStatement p = conn.prepareStatement("SELECT * FROM " + "  COMMODITIES_LIST");
	ResultSet r = p.executeQuery();
	List arrayList = new ArrayList();
	while   (r.next())   
		{
		Commodity commodity = new Commodity();
		commodity.setId(r.getInt("ID"));
		commodity.setName(r.getString("NAME"));
		commodity.setDescription(r.getString("DESCRIPTION"));
		commodity.setPrice(r.getDouble("PRICE"));
		commodity.setImagePath(r.getString("IMAGEPATH"));
		arrayList.add(commodity);
		}
	conn.close(); 
	return arrayList;
	}
/*
Во втором методе выполняется поиск товара по его ID. Если такой товар найден, то возвращается 
созданный по ResultSet объект Commodity.
*/

public Commodity getCommodityById(int id)   throws SQLException  
	{ 
	if   (dataSource == null)
	throw new SQLException("Datasource not loaded");
	Connection conn = dataSource.getConnection();
	PreparedStatement p = conn.prepareStatement
		("SELECT * FROM " + "  COMMODITIES_LIST WHERE ID=?");
	p.setInt(1,  id);
	ResultSet r = p.executeQuery();
	Commodity commodity = new Commodity();
	if   (r.next())   
		{
		commodity.setId(r.getInt("ID"));
		commodity.setName(r.getString("NAME"));
		commodity.setDescription(r.getString("DESCRIPTION"));
		commodity.setPrice(r.getDouble("PRICE"));
		commodity.setImagePath(r.getString("IMAGEPATH"));
		}
	conn.close(); return commodity;
	}

public void ejbCreate()   
	{
	}

public void ejbActivate()   throws EJBException,   RemoteException  
	{
	}
public void ejbPassivate()   throws EJBException,   RemoteException  
	{
	}
public void ejbRemove()   throws EJBException,   RemoteException  
	{
	}
public void setSessionContext(SessionContext arg0)   throws EJBException, RemoteException  
	{
	try 
		{
		InitialContext ctx = new InitialContext(); 
		if   (dataSource == null)
		dataSource =   (DataSource)   ctx.lookup("java:/OracleDS"); 
		}   
	catch   (NamingException ex)   
		{
		throw new EJBException(ex);
		}
	}
}

public class TestClient  
{
public static void main(String args[])   
	{
	try 
		{
		Context jndiContext = createJBossContext();
		Object ref = jndiContext.lookup("CommoditiesListBean"); 
		CommoditiesListHome home =   
			(CommoditiesListHome) PortableRemoteObject.narrow(ref, CommoditiesListHome.class);
		CommoditiesListRemote remote = home.create();
		System.out.println("There are following items available " +" in stock:");
		List list = remote.getAvailableCommodities(); 
		Iterator iter = list.iterator();
		while   (iter.hasNext())   
			{
			Commodity commodity = (Commodity) iter.next(); 
			System.out.println(commodity.toString());
			}
		Commodity commodity = remote.getCommodityById(2); 
		System.out.println("Single commotidy -  " + commodity.toString());
		}   
	catch   (RemoteException e)   
		{
		e.printStackTrace(); 
		}   
	catch   (NamingException e)   
		{
		e.printStackTrace(); 
		}   
	catch   (CreateException e)   
		{
		e.printStackTrace(); 
		}   
	catch   (SQLException e)   
		{
		e.printStackTrace();
		}
	}
public static Context createJBossContext()   throws NamingException  
	{
	Properties p = new Properties();
	p.put("java.naming.factory.initial",
	"org.jnp.interfaces.NamingContextFactory");
	p.put("java.naming.provider.url",   "jnp://127.0.0.1:1099");
	p.put("java.naming.factory.url.pkgs", "org.jboss.naming:org.jnp.interfaces");
	
	Context jndiContext = new InitialContext(p);
	return jndiContext;
	}
}