roomvaluefactory.java

来自「100多M的J2EE培训内容」· Java 代码 · 共 78 行

package com.borland.training.meetings.sessions;

import java.util.*;
import javax.ejb.*;
import javax.naming.*;
import com.borland.training.meetings.entities.*;

class RoomValueFactory {

  private static RoomValueFactory instance = null;
  private EJBHomeFactory homeFactory;

  private RoomValueFactory() throws NamingException {
    homeFactory = EJBHomeFactory.getInstance();
  }

  public static RoomValueFactory getInstance() throws NamingException {
    if(instance == null) {
      instance = new RoomValueFactory();
    }
    return instance;
  }

  public RoomValue getRoom(String name)
    throws FinderException, NamingException {

    Room room = findRoom(name);
    return createValue(room);
  }

  public Collection getAllRooms()
    throws FinderException, NamingException {

    Collection rooms = findAllRooms();
    Collection roomValues = new Vector(rooms.size());
    Iterator iterator = rooms.iterator();
    Room room = null;
    while(iterator.hasNext()) {
      room = (Room) iterator.next();
      roomValues.add(createValue(room));
    }
    return roomValues;
  }
  // Helper method used by the factory or a manager
  public Room findRoom(String name)
    throws FinderException, NamingException {

    RoomHome home = (RoomHome) homeFactory.lookupByLocalEJBReference("Room");
    return home.findByPrimaryKey(name);
  }

  // Helper method used by the factory or a manager
  public Collection findAllRooms()
    throws FinderException, NamingException {

    RoomHome home = (RoomHome) homeFactory.lookupByLocalEJBReference("Room");
    return home.findAll();
  }

  // Helper method used by the factory
  private RoomValue createValue(Room room) {
    return new RoomValue(room.getName(),
      room.getCapacity(),
      getMeetingIds(room));
  }

  // Helper method used by the factory
  private Collection getMeetingIds(Room room) {
    Collection meetings = room.getMeetings();
    Collection meetingIds = new Vector(meetings.size());
    Iterator iterator = meetings.iterator();
    while(iterator.hasNext()) {
      Meeting meeting = (Meeting) iterator.next();
      meetingIds.add(meeting.getId());
    }
    return meetingIds;
  }
}