dxabstractset.java

用Java写的面相对象的数据库管理系统

// You can redistribute this software and/or modify it under the terms of
// the Ozone Library License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-2000 by SMB GmbH. All rights reserved.
//
// $Id: DxAbstractSet.java,v 1.6 2000/10/28 16:55:14 daniela Exp $

package org.ozoneDB.DxLib;

/**
 * 
 * 
 * @author <a href="http://www.softwarebuero.de/">SMB</a>
 * @version $Revision: 1.6 $Date: 2000/10/28 16:55:14 $
 */
public abstract class DxAbstractSet extends DxAbstractCollection implements DxSet {
    
    final static long serialVersionUID = 1L;
    
    
    /** */
    public boolean equals( Object obj ) {
        if (obj instanceof DxSet && obj != null) {
            DxSet rhs = (DxSet)obj;
            
            if (this == obj) {
                return true;
            } 
            
            if (count() != rhs.count()) {
                return false;
            } 
            
            return containsAll( rhs );
        } else {
            return false;
        } 
    } 
    
    
    /**
     */
    public synchronized boolean retainAll( DxCollection coll ) {
        boolean answer = false;
        DxIterator it = iterator();
        Object obj;
        while ((obj = it.next()) != null) {
            if (!coll.contains( obj )) {
                it.removeObject();
                answer = true;
            } 
        } 
        return answer;
    } 
    
}