jmsdelegate.java

我在加拿大学习的一个比较复杂的在线银行程序.

package com.ebusiness.ebank.servicedelegate;

/**
 * <p>Title: </p>
 * <p>Description:  This class delegate all visa payment to an asynchronous JMS call. JMS
 *                  is provided by another department within eBusiness Inc.. The ePayment application
 *                  will process the request asynchronously once the message has been sent to JMS server
 *
 *                  Since the Delegate can be used either within eBank application
 *                  or by other applications, please do not use struts and Log service
 *                  within the delegate classes.
 *                  </p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: eBusiness Inc., All right reserved</p>
 * @author
 * @version 1.0
 */

import com.ebusiness.ebank.bean.StatementValue;
import com.ebusiness.ebank.exception.SystemException;

import javax.jms.QueueConnectionFactory;
import javax.jms.QueueConnection;
import javax.jms.QueueSession;
import javax.jms.Session;
import javax.jms.QueueSender;
import javax.jms.Queue;
import javax.jms.TextMessage;
import javax.naming.InitialContext;

import java.util.Calendar;
import java.math.BigDecimal;

import java.io.StringWriter;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import com.ebusiness.epayment.xmlbinding.*;

/**
 * The class is used to send messages to the queue.
 *
 */
public class JMSDelegate
{
    private static QueueConnectionFactory qconFactory;

    private static Queue queue;

    private static Marshaller m;

    private static ObjectFactory objFactory;

    /**
     * Creates all the necessary objects for sending message
     */
    static
    {
        try
        {
           //  Hashtable h = new Hashtable();
           //  h.put(Context.INITIAL_CONTEXT_FACTORY,
             //      "weblogic.jndi.WLInitialContextFactory");
             //h.put(Context.PROVIDER_URL, "iiop://localhost:9001");
             //h.put(Context.SECURITY_PRINCIPAL, "rbcJMS");
             //h.put(Context.SECURITY_CREDENTIALS, "admin1234");
             InitialContext ctx = new InitialContext();
             qconFactory = (QueueConnectionFactory) ctx.lookup("jms/ebank/QueueConnectionFactory");
             System.out.println(qconFactory == null? "QconFactory is Null" : "QconFactory is NOT Null");
             queue = (Queue) ctx.lookup("jms/ebank/Queue");
             System.out.println(queue == null? "Que is Null" : "Que is NOT Null");
              JAXBContext jc = JAXBContext.newInstance("com.ebusiness.epayment.xmlbinding");
              m = jc.createMarshaller();
              m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
              objFactory = new ObjectFactory();
        }
        catch (Exception e)
        {
            e.printStackTrace();
            System.out.println("FATAL: JMS static block" + e.getMessage());
        }
    }

    /**
     * Sends a message to a JMS queue.
     *
     * @param message  message to be sent
     * @exception JMSException if JMS fails to send message due to internal error
     */
    public static void sendPayment(StatementValue sValue) throws SystemException
    {
        QueueConnection qCon = null;
        QueueSession qSession = null;
        QueueSender qSender = null;
        try
        {
            System.out.println(qconFactory == null? "QconFactory is Null" : "QconFactory is NOT Null");
            qCon = qconFactory.createQueueConnection();
            System.out.println(qCon == null? "Qcon is Null" : "Qcon is NOT Null");
            //qCon.start();
            qSession = qCon.createQueueSession(false, Session.AUTO_ACKNOWLEDGE); //transacted
            System.out.println(qSession == null? "Que is Null" : "Que is NOT Null");
            qSender = qSession.createSender(queue);
            TextMessage msg = qSession.createTextMessage();
            msg.setText(createXMLMsg(sValue));
            qCon.start();
            qSender.send(msg);
        }
        catch (Exception e)
        {
            e.printStackTrace();
            throw new SystemException(e);
        }
        finally
        {
            try
            {
                //there is no need to close session, producer when the connnection
                //object is closed.
                if (qCon != null)
                   qCon.close();
            }
            catch(Exception e)
            {
                e.printStackTrace();
            }
        }
    }

    private static String createXMLMsg(StatementValue sValue) throws Exception
    {
       BankingValue bValue = objFactory.createBankingValue();
       StringWriter sr = new StringWriter();
       Calendar bankingDate = Calendar.getInstance();
       bankingDate.setTime(sValue.getBankingDate());
       bValue.setBankingDate(bankingDate);
       bValue.setDescription(sValue.getDescription());
       bValue.setWithdrawal(new BigDecimal(sValue.getWithdrawal()));
       bValue.setDeposit(new BigDecimal(sValue.getDeposit()));
       bValue.setAccountNo(sValue.getAccountNo());
       bValue.setClientCardNo(sValue.getClientCardNo());
       m.marshal(bValue, sr);
       return sr.toString();
    }
}