ordermessageejb.java

《J2EE企业级应用开发》一书的配套源代码

package com.j2eeapp.cdstore.finance;

import java.rmi.RemoteException;
import javax.ejb.*;
import javax.jms.*;
import com.j2eeapp.cdstore.util.JNDINames;
import com.j2eeapp.bank.*;
import com.j2eeapp.cdstore.servicelocator.*;
import com.j2eeapp.cdstore.order.*;

public class OrderMessageEJB implements MessageDrivenBean, MessageListener
{
    
    public static final String DRAW="draw";
    public static final String DEPOSITE="deposite";
    private BankServiceHome bankHome=null;
    /**
     * Attributes declaration
    */
    public MessageDrivenContext EJB_Context = null;
    
   
    /**
     * @J2EE_METHOD  --  ejbCreate
     * Called by the container to create an instance of a message-driven bean. Each message-driven
     * bean class must have one ejbCreate method, with no arguments.
     */
    public void ejbCreate    ()  throws ServiceLocatorException
    { 
		try
		{
				bankHome=(BankServiceHome)new EJBServiceLocator().getRemoteHome(JNDINames.BANK,BankServiceHome.class);
		}
		catch(ServiceLocatorException ex)
		{
			throw new ServiceLocatorException("could not get worker: "+ex);
		}
    }
    
    /**
     * @J2EE_METHOD  --  onMessage
     * Called by the bean's container when a message has arrived for the bean to service.
     * It contains the business logic that handles the processing of the message. Only
     * message-driven beans can asynchronously receive messages. Session and entity beans
     * are not permitted to be JMS MessageListener.
     */
    public void onMessage    (Message msg)  
    { 
		try
		{
			if(msg instanceof MapMessage)
			{
				
				MapMessage map=(MapMessage)msg;
				BankService bank=bankHome.findByPrimaryKey(map.getString("cardNumber"));
				if(bank==null) return;
				if(map.getString("action").equals(DRAW))
				{
					try
					{
						boolean re=bank.withdrawFunds(map.getFloat("amountOfMoney"),map.getString("cardPassword"));
						if(re)
						{
							setOrderStatus(map.getString("orderId"),OrderStatusLocalHome.ORDER_STATUS_CONFIRMED);
							System.out.println("orderStatus has been set to confirmed");
							return;
						}
						else
						{
							System.out.println("withdraw money occur error");
							return;
						}
					}
					catch(Exception e)
					{
						System.out.println(e.getMessage());
					}
				}//if
				else
				{
					try
					{
						boolean re=bank.addFunds(map.getFloat("amountOfMoney"));
					}
					catch(Exception e)
					{
						System.out.println(e.getMessage());
					}
				}//else
			}//if msg
		}
		catch(Exception e2)
		{
			System.out.println(e2.getMessage());
		}
	}
			
  
    public void setOrderStatus(String orderId,String status)throws ServiceLocatorException
    {
    	try
		{
    		OrderLocalHome orderHome=(OrderLocalHome)new EJBServiceLocator().getLocalHome(JNDINames.ORDER);
			OrderLocal order=orderHome.findByPrimaryKey(orderId);
			order.getOrderStatus().setStatus(status);
			
		}
		catch(Exception e)
		{
				System.out.println(e.getMessage());
		}
	}	
							
    
    
    /**
     * @J2EE_METHOD  --  ejbRemove
     * A container invokes this method before it ends the life of the message-driven object.
     * This happens when a container decides to terminate the message-driven object. This
     * method is called with no transaction context. 
     */
    public void ejbRemove    ()  
    { 

    }
    
    /**
     * @J2EE_METHOD  --  setMessageDrivenContext
     * Set the associated message-driven context. The container calls this method after the
     * instance creation. The enterprise Bean instance should store the reference to the
     * context object in an instance variable. This method is called with no transaction
     * context.
     */
    public void setMessageDrivenContext    (MessageDrivenContext ctx)  
    { 
		this.EJB_Context=ctx;
    }
}