package examples.ejb.subclass.child;

import javax.ejb.*;
import javax.naming.*;
import java.io.Serializable;
import java.rmi.RemoteException;
import java.util.*;

import examples.ejb.subclass.parent.*;

/**
 * ChildBean is a stateless SessionBean. This bean illustrates:
 * <ul>
 * <li> Child class to the ParentBean class
 * <li> Using subclassing to simplify related bean classes
 * <li> Contains only methods that are either unique to the Child class
 * or overload methods in the Parent Bean
 * <li> Using JNDI to look up and call another bean from
 * within a bean (<a href="#callParentBean()"><tt>callParentBean</tt></a>)
 * </ul>
 *
 * @author Copyright (c) 1998 by WebLogic, Inc. All Rights Reserved.
 * @author Copyright (c) 1998-1999 by BEA Systems, Inc. All Rights Reserved.
 */
public class ChildBean extends examples.ejb.subclass.parent.ParentBean 
  implements SessionBean {

  /**
   * Returns a message identifying the method.
   * This method is unique to the Child bean.
   *
   * @return                  String Message
   */
  public String childSaysHello() {
    return "Hello from the ChildBean.";
  }

  /**
   * Returns a message identifying the method.
   * This method is inherited and overloaded by the Child bean.
   *
   * @return                  String Message
   */
  public String parentSaysHello() {
    return "Hello from the ChildBean overload of the \"parentSaysHello()\" method.";
  }

  /**
   * Looks up a parent bean and calls its 
   * <tt>parentMethodOnly()</tt>. Returns a message identifying the method.
   * <ul>
   * <li> Demonstrates calling one bean from another bean
   * <li> Uses <tt>SessionContext ctx</tt> to generate a new <tt>Context</tt>
   * <li> Uses that <tt>Context</tt> to find the <tt>ParentHome</tt>
   * </ul>
   * @return                  String Message
   * @exception               RemoteException if there is
   *                          a communications or systems failure
   */
  public String callParentBean() throws RemoteException {
    String message = "ChildBean calling a ParentBean method:\n";

    try {
      Context context = new InitialContext(ctx.getEnvironment());
      ParentHome parentHome = (ParentHome) context.lookup("parent.ParentHome");

      Parent parent = parentHome.create();

      message = message + parent.parentMethodOnly();
      return message;
    }
    catch (Exception e) {
      throw new RemoteException(e.getMessage());
    }
  }

}