/* ====================================================================   Copyright 2002-2004   Apache Software Foundation   Licensed under the Apache License, Version 2.0 (the "License");   you may not use this file except in compliance with the License.   You may obtain a copy of the License at       http://www.apache.org/licenses/LICENSE-2.0   Unless required by applicable law or agreed to in writing, software   distributed under the License is distributed on an "AS IS" BASIS,   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   See the License for the specific language governing permissions and   limitations under the License.==================================================================== */        package org.apache.poi.poifs.filesystem;/** * Class DocumentDescriptor * * @author Marc Johnson (mjohnson at apache dot org) * @version %I%, %G% */public class DocumentDescriptor{    private POIFSDocumentPath path;    private String            name;    private int               hashcode = 0;    /**     * Trivial constructor     *     * @param path the Document path     * @param name the Document name     */    public DocumentDescriptor(final POIFSDocumentPath path, final String name)    {        if (path == null)        {            throw new NullPointerException("path must not be null");        }        if (name == null)        {            throw new NullPointerException("name must not be null");        }        if (name.length() == 0)        {            throw new IllegalArgumentException("name cannot be empty");        }        this.path = path;        this.name = name;    }    /**     * equality. Two DocumentDescriptor instances are equal if they     * have equal paths and names     *     * @param o the object we're checking equality for     *     * @return true if the object is equal to this object     */    public boolean equals(final Object o)    {        boolean rval = false;        if ((o != null) && (o.getClass() == this.getClass()))        {            if (this == o)            {                rval = true;            }            else            {                DocumentDescriptor descriptor = ( DocumentDescriptor ) o;                rval = this.path.equals(descriptor.path)                       && this.name.equals(descriptor.name);            }        }        return rval;    }    /**     * calculate and return the hashcode     *     * @return hashcode     */    public int hashCode()    {        if (hashcode == 0)        {            hashcode = path.hashCode() ^ name.hashCode();        }        return hashcode;    }    public String toString()    {        StringBuffer buffer = new StringBuffer(40 * (path.length() + 1));        for (int j = 0; j < path.length(); j++)        {            buffer.append(path.getComponent(j)).append("/");        }        buffer.append(name);        return buffer.toString();    }}   // end public class DocumentDescriptor