traderbean.java

java ejb----html jsp

package com.genuitec.traderx.ejb;

import javax.ejb.CreateException;
import javax.ejb.EJBException;
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;
import javax.naming.InitialContext;
import javax.naming.NamingException;

/**
 * XDoclet-based stateless session bean.  The class must be declared
 * <code>public</code>, according to the EJB specification.<br>
 * 
 * To generate code:  
 * <br>
 * <ul>
 * <li> Add Standard EJB module to XDoclet project properties
 * <li> Customize XDoclet configuration
 * <li> Run XDoclet
 * </ul>
 * <br>
 * Please see the included XDoclet Overview 
 * and the XDoclet Reference in the help system for details
 * 
 * @ejb.bean name = "Trader"
 *           type = "Stateless"
 *           display-name = "Trader"
 *           description = "Trader EJB"
 *           view-type = "remote"
 *           jndi-name = "ejb/com/genuitec/trader/ejb/TraderHome"
 * @ejb.env-entry name = "tradeLimit" value = "500" type = "java.lang.Integer"
 * @weblogic.enable-call-by-reference True
 * @jonas.bean ejb-name = "Trader"
 *             jndi-name = "ejb/com/genuitec/trader/ejb/TraderHome"
 * @oc4j.bean ejb-name = "Trader"
 *             jndi-name = "ejb/com/genuitec/trader/ejb/TraderHome"
 */
public class TraderBean implements SessionBean {

	/** The SessionContext */
	private SessionContext context;

	private int tradeLimit;

	
	private void log(String s) {
		System.out.println(s);
	} 

	/**
	 * An <code>ejbCreate</code> method as required by the EJB specification. <br>
	 * 
	 * The container calls the instance抯 <code>ejbCreate</code> method whose 
	 * signature matches the signature of the <code>create</code> method invoked 
	 * by the client. The input parameters sent from the client are passed to
	 * the <code>ejbCreate</code> method. Each session bean class must have at
	 * least one <code>ejbCreate</code> method. The number and signatures
	 * of a session bean抯 <code>create</code> methods are specific to each 
	 * session bean class.
	 * 
	 * @throws CreateException Thrown if the instance could not perform 
	 * the function requested by the container because of an system-level error.
	 * 
	 * @ejb.create-method
	 */
	public void ejbCreate() throws CreateException {
		log("ejbCreate called");

		try {
		  InitialContext ic = new InitialContext();

		  Integer tl = (Integer) ic.lookup("java:comp/env/tradeLimit");
    
		  tradeLimit = tl.intValue();
		} catch (NamingException ne) {
		  throw new CreateException("Failed to find environment value "+ne);
		}
	}

	/**
	 * The <code>ejbActivate()</code> method as required by the EJB specification.<br>
	 *
	 * The activate method is called when the instance is activated from its 
	 * passive" state. The instance should acquire any resource that it has 
	 * released earlier in the <code>ejbPassivate()</code> method. <br>
	 * 
	 * This method is called with no transaction context. 
	 * 
	 * @throws EJBException Thrown if the instance could not perform 
	 * the function requested by the container because of an system-level error.
	 */
	public void ejbActivate() throws EJBException {
	}

	/**
	 * The <code>ejbPassivate()</code> method as required by the EJB specification.<br>
	 *
	 * The activate method is called when the instance is activated from 
	 * its "passive" state. The instance should acquire any resource that 
	 * it has released earlier in the <code>ejbActivate()</code> method.  <br>
	 * 
	 * This method is called with no transaction context. 
	 * 
	 * @throws EJBException Thrown if the instance could not perform 
	 * the function requested by the container because of an system-level error.
	 */
	public void ejbPassivate() throws EJBException {
	}

	/**
	 * The <code>ejbRemove()</code> method as required by the EJB specification.<br>
	 *
	 * A container invokes this method before it ends the life of the 
	 * session object. This happens as a result of a client's invoking 
	 * a remove operation, or when a container decides to terminate the 
	 * session object after a timeout.   <br>
	 * 
	 * This method is called with no transaction context. 
	 * 
	 * @throws EJBException Thrown if the instance could not perform 
	 * the function requested by the container because of an system-level error.
	 */
	public void ejbRemove() throws EJBException {
	}

	/**
	 * Set the associated session context. The container calls this method 
	 * after the instance creation.  <br>
	 * 
	 * The enterprise bean instance should store the reference to the context 
	 * object in an instance variable. <br>
	 * 
	 * This method is called with no transaction context. 
	 * 
	 * @throws EJBException Thrown if the instance could not perform 
	 * the function requested by the container because of an system-level error.
	 */
	public void setSessionContext(SessionContext newContext)
		throws EJBException {
		context = newContext;
	}


	/**
	 * Buys shares of a stock for a named customer.
	 *
	 * @param customerName      String Customer name
	 * @param stockSymbol       String Stock symbol
	 * @param shares            int Number of shares to buy
	 * @return                  TradeResult Trade Result
	 *                          if there is an error while buying the shares
	 * 
	 * @ejb.interface-method 
	 */
	public TradeResult buy(String stockSymbol, int shares) {

	  if (shares > tradeLimit) {
		log("Attempt to buy "+shares+" is greater than limit of "+tradeLimit + ".");
		shares = tradeLimit;
	  }

	  log("Buying "+shares+" shares of "+stockSymbol + ". Great move.");

	  return new TradeResult(shares, stockSymbol);
	}

	/**
	 * Sells shares of a stock for a named customer.
	 *
	 * @param customerName      String Customer name
	 * @param stockSymbol       String Stock symbol
	 * @param shares            int Number of shares to buy
	 * @return                  TradeResult Trade Result
	 *                          if there is an error while selling the shares
	 * 
	 * @ejb.interface-method 
	 */
	public TradeResult sell(String stockSymbol, int shares) {

	  if (shares > tradeLimit) {
		log("Attempt to sell "+shares+" is greater than limit of "+tradeLimit);
		shares = tradeLimit;
	  }

	  log("Selling "+shares+" shares of "+stockSymbol);

	  return new TradeResult(shares, stockSymbol);
	}
}