iocontainer.java

著名的开源仿真软件yale

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2002, 2003
 *      Simon Fischer, Ralf Klinkenberg, Ingo Mierswa, 
 *          Katharina Morik, Oliver Ritthoff
 *      Artificial Intelligence Unit
 *      Computer Science Department
 *      University of Dortmund
 *      44221 Dortmund,  Germany
 *  email: [e-mail]
 *  web:   http://yale.cs.uni-dortmund.de/
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as 
 *  published by the Free Software Foundation; either version 2 of the
 *  License, or (at your option) any later version. 
 *
 *  This program 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
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 */
package edu.udo.cs.yale.operator;

import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

/** Input for Operator.apply(). Instances of this class are containers for IOObjects.
 *  They are available by calling one of the <tt>getInput</tt> methods. The operator can 
 *  choose between keeping the IOObject in the container or delete it using it.<br>
 * 
 *  @see edu.udo.cs.yale.operator.IOObject
 *
 *  @author Simon, Ingo
 *  @version $Id: IOContainer.java,v 2.2 2003/05/14 13:33:20 fischer Exp $
 */
public class IOContainer {

    private List ioObjects;

    /** Creates a new IOContainer containing the contents of the Collection which must
     *  contain only IOObjects. */
    public IOContainer(Collection obj) {
	ioObjects = new LinkedList();
	ioObjects.addAll(obj);
    }

    public IOContainer(IOObject[] obj) {
	ioObjects = new LinkedList();
	for (int i = 0; i < obj.length; i++) 
	    ioObjects.add(obj[i]);
    }

    public String toString() {
	String result = "IOContainer (" + ioObjects.size() + " objects):\n";
	result += ioObjects.toString();
	return result;
    }

    /** Returns all IOObjects. 
     */
    public IOObject[] getIOObjects() {
	return (IOObject[])ioObjects.toArray(new IOObject[ioObjects.size()]);
    }

    /** Gets the first IOObject which is of class cls. The returned object
     *  is removed from this IOContainer. */
    public IOObject getInput(Class cls) throws MissingIOObjectException {
	return getInput(cls, 0, true);
    }

 
    /** Gets the first IOObject which is of class cls. If remove is set to true,
     *  the object is aftwerwards removed from this IOContainer. 
     */
    public IOObject getInput(Class cls, boolean remove) throws MissingIOObjectException {
	return getInput(cls, 0, remove);
    }

    /** Gets the nr-th IOObject which is of class cls. If remove is set to true,
     *  the object is aftwerwards removed from this IOContainer. 
     */
    public IOObject getInput(Class cls, int nr, boolean remove) throws MissingIOObjectException {
	int n = 0; // Zaehler fuer n-te Vorkommen der Klasse cls
	Iterator i = ioObjects.listIterator();
	while (i.hasNext()) {
	    IOObject object = (IOObject)i.next();
	    if ((object != null) && (cls.isAssignableFrom(object.getClass()))) {
		if (n == nr) {
		    if (remove) i.remove();
		    return object;
		} else {
		    n++;
		}
	    }
	}
	throw new MissingIOObjectException(cls, "No object of class "+cls+ " found in input");
    }


    /** Creates a new IOContainer containing all IOObjects in output plus all
     *  IOObjects in this container.
     */
    public IOContainer append(IOObject[] output) {
	List newObjects = new LinkedList();
	for (int i = 0; i < output.length; i++) 
	    newObjects.add(output[i]);
	newObjects.addAll(ioObjects);
	return new IOContainer(newObjects);
    }

    /** Creates a new IOContainer containing all IOObjects in output plus all
     *  IOObjects in this container.
     */
    public IOContainer prepend(IOObject[] output) {
	List newObjects = new LinkedList();
	newObjects.addAll(ioObjects);
	for (int i = 0; i < output.length; i++) 
	    newObjects.add(output[i]);
	return new IOContainer(newObjects);
    }


    /** Appends this container's IOObjects to output. 
     */
    public IOContainer append(Collection output) {
	List newObjects = new LinkedList();
	newObjects.addAll(output);
	newObjects.addAll(ioObjects);
	return new IOContainer(newObjects);
    }

    public IOContainer copy() {
	return new IOContainer(ioObjects);
    }
}