orderlineitembean.java

一本关于ＥＪＢ的书

package examples;

import javax.naming.*;
import javax.ejb.*;
import java.util.*;

/**
 * This is a container-managed persistent entity bean.  It
 * represents an order line-item.  A line-item is an order
 * for a quantity of a single product.  Many line-items
 * together form an entire order.
 */
public abstract class OrderLineItemBean implements EntityBean {

	protected EntityContext ctx;

	//------------------------------------------------
	// Begin business methods
	//------------------------------------------------

	public OrderLineItemBean() {
	  System.out.println("OrdrLineItem created.");
	}

	/*
	 * The id number of this line item.  This is our
	 * primary key as well.
     * Returns the id of the customer
	 */
	public abstract String getOrderLineItemID();
    
    /**
     * Sets the id of the customer
     */
	public abstract void setOrderLineItemID(String id);

	/**
	 * Returns the Order entity bean that this line item is part of.
	 */
	public abstract Order getOrder();
    
    /**
     * Sets the Order entity bean that this line item is part of.
     */
	public abstract void setOrder(Order order);

	/**
	 * The Product entity bean that has been purchased.
	 */
	public abstract Product getProduct();
    
    /**
     * Sets the associated product EJB Object
     */
    
	public abstract void setProduct(Product product);

	/**
	 * The quantity of this product to be ordered
	 */
	public abstract int getQuantity();
    /**
     * Sets the number of items
     */
	public abstract void setQuantity(int quantity);	
	
    /*
	 * The discount of this product to be ordered
	 */
	public abstract double getDiscount();
    
    /**
     * Sets the discount of  this product
     */
	public abstract void setDiscount(double discount);	
	
	//------------------------------------------------
	// End business methods
	//------------------------------------------------

	//------------------------------------------------
	// Begin EJB-required methods.
	//------------------------------------------------

	/**
	 * Associates this Bean instance with a particular
	 * context.  Once done, we can query the Context
	 * for environment info, such as Bean
	 * customizations via properties.
	 */
	public void setEntityContext(EntityContext ctx) {
		System.out.println("OrderLineItem.setEntityContext called");
		this.ctx = ctx;
	}

	/**
	 * Disassociates this Bean instance with a
	 * particular context environment.
	 */
	public void unsetEntityContext() {
		System.out.println("OrderLineItem.unsetEntityContext called");
		this.ctx = null; 
	}

	/**
	 * Called directly after activating this bean
	 * instance.  You should acquire needed
	 * resources in this method.
	 */
	public void ejbActivate() {
		System.out.println("OrderLineItem.ejbActivate() called.");
	}

	/**
	 * Called directly before passivating this bean
	 * instance.  Release any resources you acquired
	 * in ejbActivate() in this method.
	 */
	public void ejbPassivate() {
		System.out.println("OrderLineItem.ejbPassivate () called.");
	}

	/**
	 * Updates the database to reflect the current
	 * values of this object.
	 *
	 * Since we're using Container-Managed
	 * Persistence, the Container will automatically
	 * save our public container-managed fields into
	 * the database.  We should perform any
	 * necessary pre-processing here.
	 */
	public void ejbStore() {
		System.out.println("OrderLineItem.ejbStore() called.");
	}

	/**
	 * Updates this object to reflect any changes to
	 * the database data.
	 *
	 * Since we're using Container-Managed
	 * Persistence, the Container will automatically
	 * set our public fields to the correct values.
	 * We then do post-processing here.
	 */
	public void ejbLoad() {
		System.out.println("OrderLineItem.ejbLoad() called.");
	}

	/**
	 * Called when new database data is created.
	 *
	 * When the client calls the Home Object's
	 * create() method, the Home Object then calls
	 * this ejbCreate() method.
	 *
	 * We need to initialize our Bean's container-
	 * managed fields with the parameters passed
	 * from the client, so that the Container can
	 * inspect our Bean and create the corresponding
	 * database entries.
	 */
	public String ejbCreate(String orderLineItemID, Order order, Product product, int quantity, double discount) throws CreateException {
		System.out.println("OrderLineItem.ejbCreate(" + orderLineItemID + ") called.");

                setOrderLineItemID(orderLineItemID);
		setQuantity(quantity);
                setDiscount(discount);
		/*
		 * CMP entity beans' ejbCreate() always return null.
		 * The ejbCreate() method has a non-void return signature so
		 * that the ejbCreate() signature matches that of a
		 * BMP entity bean, allowing you to create a BMP entity bean
		 * that subclasses a CMP entity bean.
		 */
		return null;
	}

	/**
	 * The Container calls this after ejbCreate().
	 * At this point in time, the bean instance is
         *
         *
	 * associated with its own EJB Object.  You can
	 * get a reference to that EJB Object by querying
	 * the context.  You'd use that EJB Object
	 * reference when calling an external module, and
	 * you'd like to pass a reference to yourself.
	 */
	public void ejbPostCreate(String orderLineItemID, Order order, Product product, int quantity,double discount) throws CreateException {
		System.out.println("OrderLineItem.ejbPostCreate() called");
        setProduct(product);
		setOrder(order);
		
	}

	/**
	 * Called before the container removes entity
	 * bean data from the database.  Corresponds to
	 * when client calls home.remove().
	 */
	public void ejbRemove() {
		System.out.println("OrderLineItem.ejbRemove() called.");
	}

	// No finder methods - they are implemented by Container

	//------------------------------------------------
	// End EJB-required methods
	//------------------------------------------------
}