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.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.poi.hpsf.ClassID; import org.apache.poi.poifs.dev.POIFSViewable; import org.apache.poi.poifs.property.DirectoryProperty; import org.apache.poi.poifs.property.DocumentProperty; import org.apache.poi.poifs.property.Property; /** * Simple implementation of DirectoryEntry */ public class DirectoryNode extends EntryNode implements DirectoryEntry, POIFSViewable, Iterable<Entry> { // Map of Entry instances, keyed by their names private final Map<String, Entry> _byname = new HashMap<>(); // Our list of entries, kept sorted to preserve order private final ArrayList<Entry> _entries = new ArrayList<>(); // the POIFSFileSystem we belong to private final POIFSFileSystem _filesystem; // the path described by this document private final POIFSDocumentPath _path; /** * create a DirectoryNode. This method is not public by design; it * is intended strictly for the internal use of this package * * @param property the DirectoryProperty for this DirectoryEntry * @param filesystem the {@link POIFSFileSystem} we belong to * @param parent the parent of this entry */ DirectoryNode(final DirectoryProperty property, final POIFSFileSystem filesystem, final DirectoryNode parent) { super(property, parent); this._filesystem = filesystem; if (parent == null) { _path = new POIFSDocumentPath(); } else { _path = new POIFSDocumentPath(parent._path, new String[] { property.getName() }); } Iterator<Property> iter = property.getChildren(); while (iter.hasNext()) { Property child = iter.next(); Entry childNode; if (child.isDirectory()) { DirectoryProperty childDir = (DirectoryProperty) child; childNode = new DirectoryNode(childDir, _filesystem, this); } else { childNode = new DocumentNode((DocumentProperty) child, this); } _entries.add(childNode); _byname.put(childNode.getName(), childNode); } } /** * @return this directory's path representation */ public POIFSDocumentPath getPath() { return _path; } /** * @return the filesystem that this belongs to */ public POIFSFileSystem getFileSystem() { return _filesystem; } /** * open a document in the directory's entry's list of entries * * @param documentName the name of the document to be opened * * @return a newly opened DocumentInputStream * * @exception IOException if the document does not exist or the * name is that of a DirectoryEntry */ public DocumentInputStream createDocumentInputStream(final String documentName) throws IOException { return createDocumentInputStream(getEntry(documentName)); } /** * open a document in the directory's entry's list of entries * * @param document the document to be opened * * @return a newly opened DocumentInputStream or DocumentInputStream * * @exception IOException if the document does not exist or the * name is that of a DirectoryEntry */ public DocumentInputStream createDocumentInputStream(final Entry document) throws IOException { if (!document.isDocumentEntry()) { throw new IOException("Entry '" + document.getName() + "' is not a DocumentEntry"); } DocumentEntry entry = (DocumentEntry) document; return new DocumentInputStream(entry); } /** * create a new DocumentEntry * * @param document the new document * * @return the new DocumentEntry * * @exception IOException if the document can't be created */ DocumentEntry createDocument(final POIFSDocument document) throws IOException { DocumentProperty property = document.getDocumentProperty(); DocumentNode rval = new DocumentNode(property, this); ((DirectoryProperty) getProperty()).addChild(property); _filesystem.addDocument(document); _entries.add(rval); _byname.put(property.getName(), rval); return rval; } /** * Change a contained Entry's name * * @param oldName the original name * @param newName the new name * * @return true if the operation succeeded, else false */ boolean changeName(final String oldName, final String newName) { boolean rval = false; EntryNode child = (EntryNode) _byname.get(oldName); if (child != null) { rval = ((DirectoryProperty) getProperty()).changeName(child.getProperty(), newName); if (rval) { _byname.remove(oldName); _byname.put(child.getProperty().getName(), child); } } return rval; } /** * Delete an entry * * @param entry the EntryNode to be deleted * * @return true if the entry was deleted, else false */ boolean deleteEntry(final EntryNode entry) { boolean rval = ((DirectoryProperty) getProperty()).deleteChild(entry.getProperty()); if (rval) { _entries.remove(entry); _byname.remove(entry.getName()); try { _filesystem.remove(entry); } catch (IOException e) { // TODO Work out how to report this, given we can't change the method signature... throw new RuntimeException(e); } } return rval; } /* ********** START implementation of DirectoryEntry ********** */ /** * get an iterator of the Entry instances contained directly in * this instance (in other words, children only; no grandchildren * etc.) * * @return iterator; never null, but hasNext() may return false * immediately (i.e., this DirectoryEntry is empty). All * objects retrieved by next() are guaranteed to be * implementations of Entry. */ public Iterator<Entry> getEntries() { return _entries.iterator(); } /** * get the names of all the Entries contained directly in this * instance (in other words, names of children only; no grandchildren * etc). * * @return the names of all the entries that may be retrieved with * getEntry(String), which may be empty (if this * DirectoryEntry is empty) */ public Set<String> getEntryNames() { return _byname.keySet(); } /** * is this DirectoryEntry empty? * * @return true if this instance contains no Entry instances */ public boolean isEmpty() { return _entries.isEmpty(); } /** * find out how many Entry instances are contained directly within * this DirectoryEntry * * @return number of immediately (no grandchildren etc.) contained * Entry instances */ public int getEntryCount() { return _entries.size(); } public boolean hasEntry(String name) { return name != null && _byname.containsKey(name); } /** * get a specified Entry by name * * @param name the name of the Entry to obtain. * * @return the specified Entry, if it is directly contained in * this DirectoryEntry * * @exception FileNotFoundException if no Entry with the specified * name exists in this DirectoryEntry */ public Entry getEntry(final String name) throws FileNotFoundException { Entry rval = null; if (name != null) { rval = _byname.get(name); } if (rval == null) { // throw more useful exceptions for known wrong file-extensions if (_byname.containsKey("Workbook")) { throw new IllegalArgumentException("The document is really a XLS file"); } else if (_byname.containsKey("PowerPoint Document")) { throw new IllegalArgumentException("The document is really a PPT file"); } else if (_byname.containsKey("VisioDocument")) { throw new IllegalArgumentException("The document is really a VSD file"); } // either a null name was given, or there is no such name throw new FileNotFoundException("no such entry: \"" + name + "\", had: " + _byname.keySet()); } return rval; } /** * create a new DocumentEntry * * @param name the name of the new DocumentEntry * @param stream the InputStream from which to create the new * DocumentEntry * * @return the new DocumentEntry * * @exception IOException if the document can't be created */ public DocumentEntry createDocument(final String name, final InputStream stream) throws IOException { return createDocument(new POIFSDocument(name, _filesystem, stream)); } /** * create a new DocumentEntry; the data will be provided later * * @param name the name of the new DocumentEntry * @param size the size of the new DocumentEntry * @param writer the writer of the new DocumentEntry * * @return the new DocumentEntry * * @exception IOException if the document can't be created */ public DocumentEntry createDocument(final String name, final int size, final POIFSWriterListener writer) throws IOException { return createDocument(new POIFSDocument(name, size, _filesystem, writer)); } /** * create a new DirectoryEntry * * @param name the name of the new DirectoryEntry * * @return the new DirectoryEntry * * @exception IOException if the directory can't be created */ public DirectoryEntry createDirectory(final String name) throws IOException { DirectoryProperty property = new DirectoryProperty(name); DirectoryNode rval = new DirectoryNode(property, _filesystem, this); _filesystem.addDirectory(property); ((DirectoryProperty) getProperty()).addChild(property); _entries.add(rval); _byname.put(name, rval); return rval; } /** * Set the contents of a document, creating if needed, * otherwise updating. Returns the created / updated DocumentEntry * * @param name the name of the new or existing DocumentEntry * @param stream the InputStream from which to populate the DocumentEntry * * @return the new or updated DocumentEntry * * @exception IOException if the document can't be created or its content be replaced */ @SuppressWarnings("WeakerAccess") public DocumentEntry createOrUpdateDocument(final String name, final InputStream stream) throws IOException { if (!hasEntry(name)) { return createDocument(name, stream); } else { DocumentNode existing = (DocumentNode) getEntry(name); POIFSDocument nDoc = new POIFSDocument(existing); nDoc.replaceContents(stream); return existing; } } /** * Gets the storage clsid of the directory entry * * @return storage Class ID */ public ClassID getStorageClsid() { return getProperty().getStorageClsid(); } /** * Sets the storage clsid for the directory entry * * @param clsidStorage storage Class ID */ public void setStorageClsid(ClassID clsidStorage) { getProperty().setStorageClsid(clsidStorage); } /* ********** END implementation of DirectoryEntry ********** */ /* ********** START implementation of Entry ********** */ /** * is this a DirectoryEntry? * * @return true if the Entry is a DirectoryEntry, else false */ @Override public boolean isDirectoryEntry() { 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() { // if this directory is empty, we can delete it return isEmpty(); } /* ********** 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()); components.addAll(_entries); 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(); } /** * Returns an Iterator over all the entries */ public Iterator<Entry> iterator() { return getEntries(); } /* ********** END begin implementation of POIFSViewable ********** */ } // end public class DirectoryNode