Java tutorial
/* ==================================================================== Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You 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; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import org.apache.poi.poifs.dev.POIFSViewable; import org.apache.poi.poifs.property.DocumentProperty; /** * Simple implementation of DocumentEntry for OPOIFS */ public class DocumentNode extends EntryNode implements DocumentEntry, POIFSViewable { // underlying POIFSDocument instance private POIFSDocument _document; /** * create a DocumentNode. This method is not public by design; it * is intended strictly for the internal use of this package * * @param property the DocumentProperty for this DocumentEntry * @param parent the parent of this entry */ DocumentNode(final DocumentProperty property, final DirectoryNode parent) { super(property, parent); _document = property.getDocument(); } /** * get the POIFSDocument * * @return the internal POIFSDocument */ POIFSDocument getDocument() { return _document; } /* ********** START implementation of DocumentEntry ********** */ /** * get the zize of the document, in bytes * * @return size in bytes */ public int getSize() { return getProperty().getSize(); } /* ********** END implementation of DocumentEntry ********** */ /* ********** START implementation of Entry ********** */ /** * is this a DocumentEntry? * * @return true if the Entry is a DocumentEntry, else false */ @Override public boolean isDocumentEntry() { return true; } /* ********** END implementation of Entry ********** */ /* ********** START extension of Entry ********** */ /** * extensions use this method to verify internal rules regarding * deletion of the underlying store. * * @return true if it's ok to delete the underlying store, else * false */ @Override protected boolean isDeleteOK() { return true; } /* ********** END extension of Entry ********** */ /* ********** START begin implementation of POIFSViewable ********** */ /** * Get an array of objects, some of which may implement * POIFSViewable * * @return an array of Object; may not be null, but may be empty */ public Object[] getViewableArray() { return new Object[0]; } /** * Get an Iterator of objects, some of which may implement * POIFSViewable * * @return an Iterator; may not be null, but may have an empty * back end store */ public Iterator<Object> getViewableIterator() { List<Object> components = new ArrayList<>(); components.add(getProperty()); if (_document != null) { components.add(_document); } return components.iterator(); } /** * Give viewers a hint as to whether to call getViewableArray or * getViewableIterator * * @return true if a viewer should call getViewableArray, false if * a viewer should call getViewableIterator */ public boolean preferArray() { return false; } /** * Provides a short description of the object, to be used when a * POIFSViewable object has not provided its contents. * * @return short description */ public String getShortDescription() { return getName(); } /* ********** END begin implementation of POIFSViewable ********** */ } // end public class DocumentNode