reverselookupmap.java

报表设计软件,很好的

/**
 * ========================================
 * JFreeReport : a free Java report library
 * ========================================
 *
 * Project Info:  http://www.jfree.org/jfreereport/index.html
 * Project Lead:  Thomas Morgner ([e-mail]);
 *
 * (C) Copyright 2000-2003, by Simba Management Limited and Contributors.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * ------------------------------
 * ReverseLookupHashMap.java
 * ------------------------------
 * (C)opyright 2003, by Thomas Morgner and Contributors.
 *
 * Original Author:  Thomas Morgner;
 * Contributor(s):   David Gilbert (for Simba Management Limited);
 *
 * $Id: ReverseLookupMap.java,v 1.2 2004/04/20 18:54:42 taqua Exp $
 *
 * Changes
 * -------------------------
 * 21.10.2003 : Initial version
 *
 */

package org.jfree.designer.propertyeditors;

import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;

public final class ReverseLookupMap
{
  private final HashMap forward;
  private final HashMap reverse;

  public ReverseLookupMap ()
  {
    forward = new HashMap();
    reverse = new HashMap();
  }

  public final int size ()
  {
    return forward.size();
  }

  public final Iterator keys ()
  {
    return Collections.unmodifiableMap(forward).keySet().iterator();
  }

  public final Iterator values ()
  {
    return Collections.unmodifiableMap(reverse).keySet().iterator();
  }

  public final void put (final Object key, final Object value)
  {
    forward.put(key, value);
    reverse.put(value, key);
  }

  public final Object get (final Object key)
  {
    return forward.get(key);
  }

  public final Object getReverse (final Object key)
  {
    return reverse.get(key);
  }

  public final void clear ()
  {
    reverse.clear();
    forward.clear();
  }
}