/*

 *

 * Copyright 2000 Sun Microsystems, Inc. All Rights Reserved.

 * 

 * This software is the proprietary information of Sun Microsystems, Inc.  

 * Use is subject to license terms.

 * 

 */



import java.util.*;

import javax.ejb.*;

import java.sql.*;

import javax.sql.*;

import javax.naming.*;



public class WarehouseEJB implements SessionBean {



   private SessionContext context;

   private Connection con;

   private String dbName = "java:comp/env/jdbc/WarehouseDB";



   public void ship (String productId, String orderId, int quantity) {



      try {

         con.setAutoCommit(false);

         updateOrderItem(productId, orderId);

         updateInventory(productId, quantity);

         con.commit();

      } catch (Exception ex) {

          try {

             con.rollback();

             throw new EJBException("Transaction failed: " + ex.getMessage());

          } catch (SQLException sqx) {

              throw new EJBException("Rollback failed: " + sqx.getMessage());

          }

      }

   } 



   public String getStatus(String productId, String orderId) {



      try {

         return selectStatus(productId, orderId);

      } catch (SQLException ex) {

          throw new EJBException 

             ("Unable to fetch status due to SQLException: " 

             + ex.getMessage());

      }

   }



   public void ejbCreate() throws CreateException {



      try {

         makeConnection();

      } catch (Exception ex) {

          throw new CreateException(ex.getMessage());

      }

     

   }



   public void ejbRemove()  {



      try {

         con.close();

      } catch (SQLException ex) {

          throw new EJBException(ex.getMessage());

      }

   }



   public void ejbActivate()  {



      try {

         makeConnection();

      } catch (Exception ex) {

          throw new EJBException(ex.getMessage());

      }

   }



   public void ejbPassivate()  {



      try {

         con.close();

      } catch (SQLException ex) {

          throw new EJBException(ex.getMessage());

      }

   }



   public void setSessionContext(SessionContext context) {



      this.context = context;

   }



   public WarehouseEJB() {}



/********************* Database Routines ***********************/



   private String selectStatus(String productId, String orderId)

      throws SQLException {



      String result;



      String selectStatement =

            "select status " +

            "from order_item where product_id = ? " +

            "and order_id = ?";

      PreparedStatement prepStmt =

            con.prepareStatement(selectStatement);



      prepStmt.setString(1, productId);

      prepStmt.setString(2, orderId);



      ResultSet rs = prepStmt.executeQuery();



      if (rs.next()) {

         result = rs.getString(1);

      }

      else {

         result = "No rows found.";

      }



      prepStmt.close();

      return result;

   }



   private void updateOrderItem(String productId, String orderId)

      throws SQLException {



      String updateStatement =

            "update order_item set status =  'shipped' " +

            "where product_id = ? " +

            "and order_id = ?";



      PreparedStatement prepStmt = 

            con.prepareStatement(updateStatement);



      prepStmt.setString(1, productId);

      prepStmt.setString(2, orderId);

      prepStmt.executeUpdate();

      prepStmt.close();

   }



   private void updateInventory(String productId, int quantity)

      throws SQLException {



      String updateStatement =

            "update inventory " + 

            "set quantity = quantity - ? " +

            "where product_id = ?";



      PreparedStatement prepStmt =

            con.prepareStatement(updateStatement);



      prepStmt.setInt(1, quantity);

      prepStmt.setString(2, productId);

      prepStmt.executeUpdate();

      prepStmt.close();

   }



   private void makeConnection() 

      throws NamingException, SQLException {



      InitialContext ic = new InitialContext();

      DataSource ds = (DataSource) ic.lookup(dbName);

      con =  ds.getConnection();

   }



} // WarehouseEJB