package edu.rice.rubis.beans;
import java.rmi.RemoteException;
import javax.ejb.MessageDrivenBean;
import javax.ejb.MessageDrivenContext;
import javax.ejb.EJBException;
import javax.jms.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.rmi.PortableRemoteObject;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.io.Serializable;
/**
* This is a stateless session bean used to build the html form to buy an item.
*
* @author Emmanuel Cecchet and Julie Marguerite
* @version 1.1
*/
public class MDB_BuyNow implements MessageDrivenBean, MessageListener
{
private DataSource dataSource;
private MessageDrivenContext messageDrivenContext;
private TopicConnectionFactory connectionFactory;
private TopicConnection connection;
private Topic topic;
private TopicSession session;
private TopicPublisher replier;
private Context initialContext = null;
public MDB_BuyNow()
{
}
public void onMessage(Message message)
{
try
{
MapMessage request = (MapMessage)message;
String correlationID = request.getJMSCorrelationID();
int itemId = request.getInt("itemId");
String username = request.getString("username");
String password = request.getString("password");
// Retrieve the connection factory
connectionFactory = (TopicConnectionFactory) initialContext.lookup(BeanConfig.TopicConnectionFactoryName);
// get the post comment form
String html = getBuyNowForm(itemId, username, password);
// send the reply
TemporaryTopic temporaryTopic = (TemporaryTopic) request.getJMSReplyTo();
if (temporaryTopic != null)
{
// create a connection
connection = connectionFactory.createTopicConnection();
// create a session: no transaction, auto ack
session = connection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
TextMessage reply = session.createTextMessage();
reply.setJMSCorrelationID(correlationID);
reply.setText(html);
replier = session.createPublisher(null); // unidentified publisher
connection.start();
replier.publish(temporaryTopic, reply);
replier.close();
session.close();
connection.stop();
connection.close();
}
}
catch (Exception e)
{
throw new EJBException("Message traitment failed for MDB_BuyNow: " +e);
}
}
/**
* Authenticate the user and get the information to build the html form.
*
* @return a string in html format
* @since 1.1
*/
public String getBuyNowForm(int itemId, String username, String password) throws RemoteException
{
int userId = -1;
StringBuffer html = new StringBuffer();
PreparedStatement stmt = null;
ResultSet rs = null;
Connection conn = null;
// Authenticate the user who want to buy
if ((username != null && !username.equals("")) || (password != null && !password.equals("")))
{
TopicConnection authConnection;
TopicSession authSession;
Topic authTopic;
try
{
// create a connection
authConnection = connectionFactory.createTopicConnection();
// lookup the destination
authTopic = (Topic) initialContext.lookup(BeanConfig.PrefixTopicName+"topicAuth");
// create a session
authSession = authConnection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE); // no transaction and auto ack
}
catch (Exception e)
{
throw new EJBException("Cannot connect to message bean MDB_Auth : " +e+"
");
}
try
{
// create a requestor to receive the reply
TopicRequestor requestor = new TopicRequestor(authSession, authTopic);
// create a message
MapMessage m = authSession.createMapMessage();
// set parameters
m.setStringProperty("nickname", username);
m.setStringProperty("password", password);
m.setJMSCorrelationID("auth");
// send the message and receive the reply
authConnection.start(); // allows message to be delivered (default is connection stopped)
MapMessage authReply = (MapMessage)requestor.request(m);
authConnection.stop();
// read the reply
userId = authReply.getInt("userId");
// close connection and session
requestor.close(); // also close the session
authConnection.close();
}
catch (Exception e)
{
throw new EJBException("user authentication failed: " +e+"
");
}
if (userId == -1)
{
html.append("You don't have an account on RUBiS!
You have to register first.
");
return html.toString();
}
}
// Try to find the Item corresponding to the Item ID
String itemName = null, description = null;
String startDate = null, endDate = null, sellerName = null;
int quantity = 0, sellerId = -1;
float buyNow = 0;
try
{
conn = dataSource.getConnection();
stmt = conn.prepareStatement("SELECT * FROM items WHERE id=?");
stmt.setInt(1, itemId);
rs = stmt.executeQuery();
if (rs.first())
{
itemName = rs.getString("name");
description = rs.getString("description");
startDate = rs.getString("start_date");
endDate = rs.getString("end_date");
buyNow = rs.getFloat("buy_now");
quantity = rs.getInt("quantity");
sellerId = rs.getInt("seller");
}
stmt.close();
}
catch (Exception e)
{
try
{
if (stmt != null) stmt.close();
if (conn != null) conn.close();
}
catch (Exception ignore)
{
}
throw new RemoteException("Failed to execute Query for item: " +e);
}
try
{
stmt = conn.prepareStatement("SELECT nickname FROM users WHERE id=?");
stmt.setInt(1, sellerId);
ResultSet srs = stmt.executeQuery();
if (srs.first())
{
sellerName = srs.getString("nickname");
}
stmt.close();
conn.close();
}
catch (SQLException s)
{
try
{
if (stmt != null) stmt.close();
if (conn != null) conn.close();
}
catch (Exception ignore)
{
}
throw new RemoteException("Failed to execute Query for seller: " +s);
}
// Display the form for buying the item
html.append("\n| You are ready to buy this item: "+itemName+" |
\n
\n");
try
{
html.append(printItemDescriptionToBuyNow(itemId, itemName, description, buyNow, quantity, sellerId, sellerName, startDate, endDate, userId));
}
catch (Exception e)
{
throw new RemoteException("Unable to print Item description: " +e);
}
return html.toString();
}
/**
* Display item information for the Buy Now servlet
*
* @return a String containing HTML code
* @exception RemoteException if an error occurs
* @since 1.0
*/
public String printItemDescriptionToBuyNow(int itemId, String itemName, String description, float buyNow, int quantity, int sellerId, String sellerName, String startDate, String endDate, int userId) throws RemoteException
{
StringBuffer result = new StringBuffer("
"+
"\n"+
"| Item description |
\n"+
"
\n"+description+"
\n"+
"
\n"+
"