structureelement.java

一个关于java 的常用工具包

package org.jutil.structure;

/**
 * <p><b>DEPRECATED</b>A class of "components" for inplementing a 1-n binding.
 * This class is the n 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 B {
  public B() {
    $a = new StructureElement(this);
  }

  public A getA() {
    return (A)$a.getOtherEnd();
  }

  StructureElement getALink() {
    return $a;
  }
  private StructureElement $a;
}
 * </code></pre>
 *
 * <p>The binding is controlled in class A. Of course you can add a setA(A a) method to class B.</p>
 * @path    $Source: /cvsroot/org-jutil/jutil.org/src/org/jutil/structure/StructureElement.java,v $
 * @version $Revision: 1.6 $
 * @date    $Date: 2002/07/21 10:30:35 $
 * @state   $State: Exp $
 * @author  Marko van Dooren
 * @release $Name:  $
 *
 * @deprecated
 */
public class StructureElement {

 	/* The revision of this class */
	public final static String CVS_REVISION ="$Revision: 1.6 $";

/*@ 
   @ public invariant getStructureSet() != null ==>
   @                  getStructureSet().contains(this);
   @*/
  
  /**
   * Initialize a new StructureElement for the given object.
   * The new StructureElement will be unconnected.
   *
   * @param object
   *        The object at the n side of the 1-n binding.
   */
 /*@
   @ public behavior
   @
   @ pre object != null;
   @
   @ post getObject() == object;
   @ post getStructureSet() == null;
   @*/
  public StructureElement(Object object) {
    _object = object;
  }

  /**
   * Initialize a new StructureElement for the given object,
   * connected to the given StructureSet.
   *
   * @param object
   *        The object at the n side of the 1-n binding.
   */
 /*@
   @ public behavior
   @
   @ pre object != null;
   @
   @ post getObject() == object;
   @ post getStructureSet() == structureSet;
   @ post structureSet != null ==> structureSet.contains(this);
   @*/
  public StructureElement(Object object, StructureSet structureSet) {
    _object = object;
    connectTo(structureSet);
  }
    
  /**
   * Return the Object at the other end of this double binding.
   */
 /*@
   @ public behavior
   @
   @ post getStructureSet() == null ==> \result == null;
   @ post getStructureSet() != null ==> \result == getStructureSet().getObject();
   @*/
  public Object getOtherEnd() {
    if (getStructureSet() == null) {
        return null;
    }
    return getStructureSet().getObject();
  }

  /**
   * Set the 1 side of this 10n binding.
   *
   * @param set
   *        The new StructureSet this StructureElement will be connected to.
   */
 /*@
   @ public behavior
   @
   @ post getStructureSet() == structureSet;
   @ // If this StructureElement was connected before, and will now be
   @ // connected to another StructureSet, it will be removed from the first one.
   @ post \old(getStructureSet()) != null && \old(getStructureSet()) != structureSet ==>
   @      ! \old(getStructureSet()).contains(this);
   @ post structureSet != null ==> structureSet.contains(this);
   @*/
  public void connectTo(StructureSet structureSet) {
    if (structureSet != _structureSet) {
      if(_structureSet != null) {
          _structureSet.unregister(this);
      }
      _structureSet=structureSet;
      if (structureSet != null) {
          structureSet.register(this);
      }
    }
  }

  /**
   * Return the object on the n side of the 1-n binding represented by
   * this StructureElement
   */
 /*@
   @ public behavior
   @
   @ post \result != null;
   @*/
  public Object getObject() {
    return _object; 
  }
  
  /**
   * return the structureSet this StructureElement belongs to
   */
  public StructureSet getStructureSet() {
    return _structureSet;
  }
  
  /**
   * The structureSet this StructureElement belongs to
   */
  private StructureSet _structureSet;
  
  /**
   * The object on the n side of the 1-n binding.
   */
  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>*/