structureset.java

一个关于java 的常用工具包

package org.jutil.structure;
import org.jutil.java.collections.Visitor;
import java.util.HashSet;
import java.util.Set;
/**
 * <p><b>DEPRECATED</b>A class of "components" for inplementing a 1-n binding.
 * This class is the 1 side of the binding (the side where the "n"
 * is in a UML diagram).</p>
 *
 * <p>This is actually a lightweight version of the APSet-APElement combination
 * of the <a href="http://www.beedra.org">Beedra</a> framework of Jan Dockx.</p>
 *
 * <p>This class is typically using in the following way.
 * See class StructureElement for class B.</p>
 * <pre><code>
public class A {

  public A() {
    $b= new StructureSet(this);
  }

  public Set getBs() {
    return $b.getOtherEnds();
  }

  public void addB(B b) {
    $b.add(b.getALink());
  }

  public void removeB(B b) {
    $b.remove(b.getALink());
  }

  private StructureSet $b;
}
 * </code></pre>
 * @path    $Source: /cvsroot/org-jutil/jutil.org/src/org/jutil/structure/StructureSet.java,v $
 * @version $Revision: 1.7 $
 * @date    $Date: 2002/07/21 10:30:35 $
 * @state   $State: Exp $
 * @author  Marko van Dooren
 * @release $Name:  $
 *
 * @deprecated
 */
public class StructureSet {
  
	/* The revision of this class */
	public final static String CVS_REVISION ="$Revision: 1.7 $";

 //@ public invariant contains(null) == false;
 //@ public invariant getObject() != null;
 
 /*@ 
   @ public invariant (\forall StructureElement e; contains(e);
   @                    e.getStructureSet() == this);
   @*/

  /**
   * Initialize an empty StructureSet for the given object.
   *
   * @param object
   *        The 1 side of the 1-n binding
   */
 /*@
   @ public behavior
   @
   @ pre object != null;
   @
   @ post getObject() == object;
   @ post (\forall StructureElement s;; !contains(s));
   @*/
  public StructureSet(Object object) {
    _object = object;
    _elements = new HashSet();
  }
  
  /**
   * Return the object at the 1 side of the 1-n binding.
   */
  public Object getObject() {
    return _object;
  }

  /**
   * Add the given StructureElement to this StructureSet.
   *
   * @param element
   *        The StructureElement to be added.
   */
 /*@
   @ public behavior
   @
   @ post contains(element) ==> element.getStructureSet() == null;
   @ post contains(element) ==> ! contains(element);
   @*/  
  public void remove(StructureElement element) {
    if (contains(element)) {
      element.connectTo(null);
    }
  }

  /**
   * Remove the given StructureElement from this StructureSet.
   *
   * @param element
   *        The StructureElement to be removed.
   */
 /*@
   @ public behavior
   @
   @ pre element != null;
   @
   @ post element.getStructureSet() == this;
   @ post \old(element.getStructureSet()) != null &&
   @      \old(element.getStructureSet()) != this ==>
   @      ! \old(element.getStructureSet()).contains(element);
   @ post contains(element);
   @*/  
  public void add(StructureElement element) {
    element.connectTo(this);
  }
  
    
  /**
   * Return a set containing the objects at the
   * n side of the 1-n binding.
   */
 /*@
   @ public behavior
   @
   @ post (\forall Object o;;
   @       \result.contains(o) <==> 
   @       (\exists StructureElement s; contains(s);
   @         s.getObject().equals(o)));
   @ post \result != null;
   @*/
  public Set getOtherEnds() {
    final HashSet result = new HashSet();
    new Visitor() {
      public void visit(Object element) {
        result.add(((StructureElement)element).getObject());
      }
    }.applyTo(_elements);
    return result;
  }
  
  
  /**
   * Return a set containing the StructureElements at the
   * n side of the 1-n binding.
   */
 /*@
   @ public behavior
   @
   @ post (\forall StructureElement s;;
   @       contains(s) <==> \result.contains(s));
   @ post \result != null;
   @*/
  public Set getStructureElements() {
    return new HashSet(_elements);
  }
  
  /**
   * Remove the given StructureElement from this StructureSet
   *
   * @param element
   *        The element to be removed.
   */
 /*@
   @ behavior
   @
   @ pre element != null;
   @
   @ post ! contains(element);
   @*/
  void unregister(StructureElement element) {
    _elements.remove(element);
  }
    
  
  /**
   * Add the given StructureElement to this StructureSet
   *
   * @param element
   *        The element to be added.
   */
 /*@
   @ behavior
   @
   @ pre element != null;
   @
   @ post contains(element);
   @*/
  void register(StructureElement element) {
    _elements.add(element);
  }
  
	/**
	 * Return the size of the StructureSet
	 */
 /*@
	 @ public behavior
	 @
	 @ post \result == (\num_of StructureElement e; contains(e);true);
	 @*/
	public int size() {
		return _elements.size();
  }
	
  /**
   * Check whether or not the given element is connected to
   * this StructureSet.
   *
   * @param element
   *        The element of which one wants to know if it is in
   *        this StructureSet.
   */
  public boolean contains(StructureElement element) {
    return _elements.contains(element);
  }
  
  /**
   * The set containing the StructureElements at the n side of the 1-n binding.
   */
 /*@
   @ private invariant ! _elements.contains(null);
   @ private invariant (\forall Object o; _elements.contains(o);
   @                      o instanceof StructureElement);
   @*/
  private HashSet _elements;
  
  /**
   * The object at the 1 side of the 1-n binding.
   */
 /*@
   @ private invariant _object != null;
   @*/
  private Object _object;
}
/*<copyright>Copyright (C) 1997-2001. This software is copyrighted by 
the people and entities mentioned after the "@author" tags above, on 
behalf of the JUTIL.ORG Project. The copyright is dated by the dates 
after the "@date" tags above. All rights reserved.
This software is published under the terms of the JUTIL.ORG Software
License version 1.1 or later, a copy of which has been included with
this distribution in the LICENSE file, which can also be found at
http://org-jutil.sourceforge.net/LICENSE. This software is distributed WITHOUT 
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
or FITNESS FOR A PARTICULAR PURPOSE. See the JUTIL.ORG Software 
License for more details.
For more information, please see http://org-jutil.sourceforge.net/</copyright>*/