cmdrecordpurchases2.java

一个简单的EJB实例.用DB2连接.JSP页面.很好用.供大家学习

package com.xyz.command;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Enumeration;

import javax.ejb.EJBException;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.rmi.PortableRemoteObject;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.xyz.ejb.SalesFacade;
import com.xyz.ejb.SalesFacadeHome;

/**
 * @author Mauget
 */
public class CmdRecordPurchases2 implements ICommand {

	/**
	 * @see com.xyz.command.ICommand#execute(HttpServletRequest, HttpServletResponse)
	 */
	public String execute(
		HttpServletRequest request,
		HttpServletResponse response)
		throws ServletException, IOException {

		String targetPage = "ErrorPage.jsp";
		Long[] itemIds = getItemIds(request);

		try {
			Context jndiContext = new InitialContext();

			Object ref = jndiContext.lookup(facRef);
			SalesFacadeHome home =
				(SalesFacadeHome) PortableRemoteObject.narrow(
					ref,
					SalesFacadeHome.class);

			SalesFacade facade = home.create();

			String zipcode = request.getParameter("zipcode");
			if (zipcode != null && facade.makePurchase(zipcode, itemIds))
				targetPage = "Purchases2.jsp";

		} catch (javax.naming.NamingException ex) {
			throw new EJBException();
		} catch (java.rmi.RemoteException ex) {
			throw new EJBException();
		} catch (javax.ejb.CreateException ex) {
			throw new EJBException();
		}
		return targetPage;
	}

	/**
	 * Helper method returns an array of Long Item IDs
	 * @param request java.servlet.HttpServletRequest
	 * @return Long[]
	 */
	private Long[] getItemIds(HttpServletRequest request) {

		ArrayList list = new ArrayList(20);
		Enumeration enum = request.getParameterNames();
		while (enum.hasMoreElements()) {
			String idStr = (String) enum.nextElement();
			if (idStr.startsWith("buy")) {
				String key = request.getParameter(idStr);
				Long id = new Long(Long.parseLong(key));
				list.add(id);
			}
		}
		return (Long[]) list.toArray(new Long[list.size()]);
	}

}