poifsfilesystem.java

Office格式转换代码

                                             batStartBlock);

        // set the property table start block
        header_block_writer.setPropertyStart(_property_table.getStartBlock());

        // set the small block allocation table start block
        header_block_writer.setSBATStart(sbtw.getSBAT().getStartBlock());

        // set the small block allocation table block count
        header_block_writer.setSBATBlockCount(sbtw.getSBATBlockCount());

        // the header is now properly initialized. Make a list of
        // writers (the header block, followed by the documents, the
        // property table, the small block store, the small block
        // allocation table, the block allocation table, and the
        // extended block allocation table blocks)
        List writers = new ArrayList();

        writers.add(header_block_writer);
        writers.addAll(_documents);
        writers.add(_property_table);
        writers.add(sbtw);
        writers.add(sbtw.getSBAT());
        writers.add(bat);
        for (int j = 0; j < xbat_blocks.length; j++)
        {
            writers.add(xbat_blocks[ j ]);
        }

        // now, write everything out
        iter = writers.iterator();
        while (iter.hasNext())
        {
            BlockWritable writer = ( BlockWritable ) iter.next();

            writer.writeBlocks(stream);
        }
    }

    /**
     * read in a file and write it back out again
     *
     * @param args names of the files; arg[ 0 ] is the input file,
     *             arg[ 1 ] is the output file
     *
     * @exception IOException
     */

    public static void main(String args[])
        throws IOException
    {
        if (args.length != 2)
        {
            System.err.println(
                "two arguments required: input filename and output filename");
            System.exit(1);
        }
        FileInputStream  istream = new FileInputStream(args[ 0 ]);
        FileOutputStream ostream = new FileOutputStream(args[ 1 ]);

        new POIFSFileSystem(istream).writeFilesystem(ostream);
        istream.close();
        ostream.close();
    }

    /**
     * get the root entry
     *
     * @return the root entry
     */

    public DirectoryEntry getRoot()
    {
        if (_root == null)
        {
            _root = new DirectoryNode(_property_table.getRoot(), this, null);
        }
        return _root;
    }

    /**
     * open a document in the root 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
    {
        Entry document = getRoot().getEntry(documentName);

        if (!document.isDocumentEntry())
        {
            throw new IOException("Entry '" + documentName
                                  + "' is not a DocumentEntry");
        }
        return new DocumentInputStream(( DocumentEntry ) document);
    }

    /**
     * add a new POIFSDocument
     *
     * @param document the POIFSDocument being added
     */

    void addDocument(final POIFSDocument document)
    {
        _documents.add(document);
        _property_table.addProperty(document.getDocumentProperty());
    }

    /**
     * add a new DirectoryProperty
     *
     * @param directory the DirectoryProperty being added
     */

    void addDirectory(final DirectoryProperty directory)
    {
        _property_table.addProperty(directory);
    }

    /**
     * remove an entry
     *
     * @param entry to be removed
     */

    void remove(EntryNode entry)
    {
        _property_table.removeProperty(entry.getProperty());
        if (entry.isDocumentEntry())
        {
            _documents.remove((( DocumentNode ) entry).getDocument());
        }
    }

    private void processProperties(final BlockList small_blocks,
                                   final BlockList big_blocks,
                                   final Iterator properties,
                                   final DirectoryNode dir)
        throws IOException
    {
        while (properties.hasNext())
        {
            Property      property = ( Property ) properties.next();
            String        name     = property.getName();
            DirectoryNode parent   = (dir == null)
                                     ? (( DirectoryNode ) getRoot())
                                     : dir;

            if (property.isDirectory())
            {
                DirectoryNode new_dir =
                    ( DirectoryNode ) parent.createDirectory(name);

                new_dir.setStorageClsid( property.getStorageClsid() );

                processProperties(
                    small_blocks, big_blocks,
                    (( DirectoryProperty ) property).getChildren(), new_dir);
            }
            else
            {
                int           startBlock = property.getStartBlock();
                int           size       = property.getSize();
                POIFSDocument document   = null;

                if (property.shouldUseSmallBlocks())
                {
                    document =
                        new POIFSDocument(name, small_blocks
                            .fetchBlocks(startBlock), size);
                }
                else
                {
                    document =
                        new POIFSDocument(name,
                                          big_blocks.fetchBlocks(startBlock),
                                          size);
                }
                parent.createDocument(document);
            }
        }
    }

    /* ********** 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()
    {
        if (preferArray())
        {
            return (( POIFSViewable ) getRoot()).getViewableArray();
        }
        else
        {
            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 getViewableIterator()
    {
        if (!preferArray())
        {
            return (( POIFSViewable ) getRoot()).getViewableIterator();
        }
        else
        {
            return Collections.EMPTY_LIST.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 (( POIFSViewable ) getRoot()).preferArray();
    }

    /**
     * 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 "POIFS FileSystem";
    }

    /* **********  END  begin implementation of POIFSViewable ********** */
}   // end public class POIFSFileSystem