salesfacadebean.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.ejb;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

import javax.ejb.EJBException;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;

import salesdb.*;

import com.xyz.data.ItemVO;
import com.xyz.data.LocationVO;

/**
 * Bean implementation class for Enterprise Bean: SalesFacade
 */
public class SalesFacadeBean implements javax.ejb.SessionBean {
	private javax.ejb.SessionContext mySessionCtx;
	/**
	 * getSessionContext
	 */
	public javax.ejb.SessionContext getSessionContext() {
		return mySessionCtx;
	}
	/**
	 * setSessionContext
	 */
	public void setSessionContext(javax.ejb.SessionContext ctx) {
		mySessionCtx = ctx;
	}
	/**
	 * ejbCreate
	 */
	public void ejbCreate() throws javax.ejb.CreateException {
	}
	/**
	 * ejbActivate
	 */
	public void ejbActivate() {
	}
	/**
	 * ejbPassivate
	 */
	public void ejbPassivate() {
	}
	/**
	 * ejbRemove
	 */
	public void ejbRemove() {
	}
	/**
	 * echo a string
	 * @param aString java.lang.String 
	 * @return java.lang.String
	 */
	public String echo(String aString) {
		return "SalesFacade: " + aString;
	}
	/**
	 * Return a LocationVO, given a ZipCode
	 * @return com.xyz.data.LocationVO, a location
	 */
	public LocationVO getLocation(String zipCode) {

		final String loRef = "java:comp/env/ejb/Location";
		LocationVO locationDO = null;

		try {
			Context jndiContext = new InitialContext();

			LocationLocalHome localHome =
				(LocationLocalHome) jndiContext.lookup(loRef);
			LocationLocal locationLocal =
				localHome.findByPrimaryKey(new LocationKey(zipCode));

			locationDO =
				new LocationVO(
					locationLocal.getCity(),
					locationLocal.getState(),
					zipCode,
					locationLocal.getAreacode());

		} catch (javax.naming.NamingException ex) {
			throw new EJBException(ex);
		} catch (javax.ejb.FinderException ex) {
			locationDO = new LocationVO("", "", "", "");
		}
		return locationDO;
	}
	/**
	 * Return array of Item data objects
	 * @return com.xyz.data.LocationVO[], an array of all locations
	 */
	public ItemVO[] getAllItems() {

		final String loRef = "java:comp/env/ejb/Item";
		ItemVO[] data = null;

		try {
			Context jndiContext = new InitialContext();

			ItemLocalHome itemLocalHome =
				(ItemLocalHome) jndiContext.lookup(loRef);

			Collection items = itemLocalHome.findAll();
			data = new ItemVO[items.size()];
			int i = 0;
			Iterator it = items.iterator();
			while (it.hasNext()) {
				ItemLocal item = (ItemLocal) it.next();
				long key =
					((ItemKey) item.getPrimaryKey()).getItemid().longValue();
				data[i++] = new ItemVO(key, item.getName());
			}

		} catch (javax.naming.NamingException ex) {
			throw new EJBException(ex);
		} catch (javax.ejb.FinderException ex) {
			data = new ItemVO[0];
		}
		return data;
	}
	/** 
	 * Create Purchase objects from list of items for a 
	 * given Zip Code
	 * @return boolean, true if and only if successful
	 */
	public boolean makePurchase(String zipCode, Long[] items) {

		final String pcRef = "java:comp/env/ejb/Purchase";
		final String loRef = "java:comp/env/ejb/Location";
		final String itRef = "java:comp/env/ejb/Item";
		long key = System.currentTimeMillis();

		try {
			Context jndiContext = new InitialContext();

			// Find local homes
			PurchaseLocalHome purchaseLocalHome =
				(PurchaseLocalHome) jndiContext.lookup(pcRef);
			LocationLocalHome locationLocalHome =
				(LocationLocalHome) jndiContext.lookup(loRef);
			ItemLocalHome itemLocalHome =
				(ItemLocalHome) jndiContext.lookup(itRef);

			// Get loop-invariant timestamp and location
			String timeStamp = new java.util.Date().toString();
			LocationLocal locationLocal =
				locationLocalHome.findByPrimaryKey(new LocationKey(zipCode));

			// Create Purchases
			for (int i = 0; i < items.length; i++) {
				ItemLocal itemLocal =
					itemLocalHome.findByPrimaryKey(new ItemKey(items[i]));

				// Create new purchase
				PurchaseLocal purchaseLocal =
					purchaseLocalHome.create(new Long(++key));

				// Set location
				purchaseLocal.setLocationfk(locationLocal);

				// Set item
				purchaseLocal.setItemfk(itemLocal);
			}

		} catch (javax.naming.NamingException ex) {
			throw new EJBException(ex);
		} catch (javax.ejb.FinderException ex) {
			return false;
		} catch (javax.ejb.CreateException ex) {
			throw new EJBException(ex);
		}
		return true;
	}
	
}