datamanager.java

A JSP Based EShop for searching books and placing Orders

package eshop.model;

import java.util.Hashtable;
import java.util.ArrayList;
import java.util.Enumeration;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

import eshop.beans.Category;
import eshop.beans.Book;
import eshop.beans.Customer;

public class DataManager {
  private String dbURL = "";
  private String dbUserName = "";
  private String dbPassword = "";

  public void setDbURL(String dbURL) {
    this.dbURL = dbURL;
    }
  public String getDbURL() {
    return dbURL;
    }

  public void setDbUserName(String dbUserName) {
    this.dbUserName = dbUserName;
    }
  public String getDbUserName() {
    return dbUserName;
    }

  public void setDbPassword(String dbPassword) {
    this.dbPassword = dbPassword;
    }
  public String getDbPassword() {
    return dbPassword;
    }

  public Connection getConnection() {
    Connection conn = null;
    try {
      conn = DriverManager.getConnection(getDbURL(), getDbUserName(),
          getDbPassword());
      }
    catch (SQLException e) {
      System.out.println("Could not connect to DB: " + e.getMessage());
      }
    return conn;
    }
  public void putConnection(Connection conn) {
    if (conn != null) {
      try { conn.close(); }
      catch (SQLException e) { }
      }
    }

  //---------- Category operations ----------
  public String getCategoryName(String categoryID) {
    Category category = CategoryPeer.getCategoryById(this, categoryID);
    return (category == null) ? null : category.getName();
    }

  public Hashtable getCategories() {
    return CategoryPeer.getAllCategories(this);
    }

  public Enumeration getCatIDs() {
    return CategoryPeer.getAllCategories(this).keys();
    }

  //---------- Book operations ----------
  public ArrayList getSearchResults(String keyword) {
    return BookPeer.searchBooks(this, keyword);
    }

  public ArrayList getBooksInCategory(String categoryID) {
    return BookPeer.getBooksByCategory(this, categoryID);
    }

  public Book getBookDetails(String bookID) {
    return BookPeer.getBookById(this, bookID);
    }

  //---------- Order operations ----------
  public long insertOrder(Customer customer, Hashtable shoppingCart) {
    long returnValue = 0L;
    long orderId = System.currentTimeMillis();
    Connection connection = getConnection();
    if (connection != null) {
      Statement stmt = null;
      try {
        connection.setAutoCommit(false);
        stmt = connection.createStatement();
        try {
          OrderPeer.insertOrder(stmt, orderId, customer);
          OrderDetailsPeer.insertOrderDetails(stmt, orderId, shoppingCart);
          try { stmt.close(); }
          finally { stmt = null; }
          connection.commit();
          returnValue = orderId;
          }
        catch (SQLException e) {
          System.out.println("Could not insert order: " + e.getMessage());
          try { connection.rollback(); }
          catch (SQLException ee) { }
          }
        }
      catch (SQLException e) {
        System.out.println("Could not insert order: " + e.getMessage());
        }
      finally {
        if (stmt != null) {
          try { stmt.close(); }
          catch (SQLException e) { }
          }
        putConnection(connection);
        }
      }
    return returnValue;
    }
  }