www.pudn.com > bookstore2.rar > BookDBAO.java

/* 
 * Copyright (c) 2005 Sun Microsystems, Inc.  All rights reserved.  U.S. 
 * Government Rights - Commercial software.  Government users are subject 
 * to the Sun Microsystems, Inc. standard license agreement and 
 * applicable provisions of the FAR and its supplements.  Use is subject 
 * to license terms. 
 * 
 * This distribution may include materials developed by third parties. 
 * Sun, Sun Microsystems, the Sun logo, Java and J2EE are trademarks 
 * or registered trademarks of Sun Microsystems, Inc. in the U.S. and 
 * other countries. 
 * 
 * Copyright (c) 2005 Sun Microsystems, Inc. Tous droits reserves. 
 * 
 * Droits du gouvernement americain, utilisateurs gouvernementaux - logiciel 
 * commercial. Les utilisateurs gouvernementaux sont soumis au contrat de 
 * licence standard de Sun Microsystems, Inc., ainsi qu'aux dispositions 
 * en vigueur de la FAR (Federal Acquisition Regulations) et des 
 * supplements a celles-ci.  Distribue par des licences qui en 
 * restreignent l'utilisation. 
 * 
 * Cette distribution peut comprendre des composants developpes par des 
 * tierces parties. Sun, Sun Microsystems, le logo Sun, Java et J2EE 
 * sont des marques de fabrique ou des marques deposees de Sun 
 * Microsystems, Inc. aux Etats-Unis et dans d'autres pays. 
 */ 
 
 
package database; 
 
import java.sql.*; 
import javax.sql.*; 
import javax.naming.*; 
import java.util.*; 
import exception.*; 
import cart.*; 
 
 
public class BookDBAO { 
    private ArrayList books; 
    Connection con; 
 
    public BookDBAO() throws Exception { 
        try { 
            InitialContext ic = new InitialContext(); 
            Context envCtx = (Context) ic.lookup("java:comp/env"); 
            DataSource ds = (DataSource) envCtx.lookup("jdbc/BookDB"); 
            con = ds.getConnection(); 
        } catch (Exception ex) { 
            throw new Exception("Couldn't open connection to database: " + 
                ex.getMessage()); 
        } 
    } 
 
    public void remove() { 
        try { 
            con.close(); 
        } catch (SQLException ex) { 
            System.out.println(ex.getMessage()); 
        } 
    } 
 
    public List getBooks() throws BooksNotFoundException { 
        books = new ArrayList(); 
 
        try { 
            String selectStatement = "select * " + "from books"; 
            PreparedStatement prepStmt = con.prepareStatement(selectStatement); 
            ResultSet rs = prepStmt.executeQuery(); 
 
            while (rs.next()) { 
                BookDetails bd = 
                    new BookDetails(rs.getString(1), rs.getString(2), 
                        rs.getString(3), rs.getString(4), rs.getFloat(5), 
                        rs.getBoolean(6), rs.getInt(7), rs.getString(8), 
                        rs.getInt(9)); 
 
                if (rs.getInt(9) > 0) { 
                    books.add(bd); 
                } 
            } 
 
            prepStmt.close(); 
        } catch (SQLException ex) { 
            throw new BooksNotFoundException(ex.getMessage()); 
        } 
 
        Collections.sort(books); 
 
        return books; 
    } 
 
    public BookDetails getBookDetails(String bookId) 
        throws BookNotFoundException { 
        try { 
            String selectStatement = "select * " + "from books where id = ? "; 
            PreparedStatement prepStmt = con.prepareStatement(selectStatement); 
            prepStmt.setString(1, bookId); 
 
            ResultSet rs = prepStmt.executeQuery(); 
 
            if (rs.next()) { 
                BookDetails bd = 
                    new BookDetails(rs.getString(1), rs.getString(2), 
                        rs.getString(3), rs.getString(4), rs.getFloat(5), 
                        rs.getBoolean(6), rs.getInt(7), rs.getString(8), 
                        rs.getInt(9)); 
                prepStmt.close(); 
 
                return bd; 
            } else { 
                prepStmt.close(); 
                throw new BookNotFoundException("Couldn't find book: " + 
                    bookId); 
            } 
        } catch (SQLException ex) { 
            System.err.println(ex.getMessage()); 
            throw new BookNotFoundException("Couldn't find book: " + bookId + 
                " " + ex.getMessage()); 
        } 
    } 
 
    public void buyBooks(ShoppingCart cart) throws OrderException { 
        Collection items = cart.getItems(); 
        Iterator i = items.iterator(); 
 
        try { 
            con.setAutoCommit(false); 
 
            while (i.hasNext()) { 
                ShoppingCartItem sci = (ShoppingCartItem) i.next(); 
                BookDetails bd = (BookDetails) sci.getItem(); 
                String id = bd.getBookId(); 
                int quantity = sci.getQuantity(); 
                buyBook(id, quantity); 
            } 
 
            con.commit(); 
            con.setAutoCommit(true); 
        } catch (Exception ex) { 
            try { 
                con.rollback(); 
                throw new OrderException("Transaction failed: " + 
                    ex.getMessage()); 
            } catch (SQLException sqx) { 
                throw new OrderException("Rollback failed: " + 
                    sqx.getMessage()); 
            } 
        } 
    } 
 
    public void buyBook(String bookId, int quantity) throws OrderException { 
        try { 
            String selectStatement = "select * " + "from books where id = ? "; 
            PreparedStatement prepStmt = con.prepareStatement(selectStatement); 
            prepStmt.setString(1, bookId); 
 
            ResultSet rs = prepStmt.executeQuery(); 
 
            if (rs.next()) { 
                int inventory = rs.getInt(9); 
                prepStmt.close(); 
 
                if ((inventory - quantity) >= 0) { 
                    String updateStatement = 
                        "update books set inventory = inventory - ? where id = ?"; 
                    prepStmt = con.prepareStatement(updateStatement); 
                    prepStmt.setInt(1, quantity); 
                    prepStmt.setString(2, bookId); 
                    prepStmt.executeUpdate(); 
                    prepStmt.close(); 
                } else { 
                    throw new OrderException("Not enough of " + bookId + 
                        " in stock to complete order."); 
                } 
            } 
        } catch (Exception ex) { 
            throw new OrderException("Couldn't purchase book: " + bookId + 
                ex.getMessage()); 
        } 
    } 
}