| |
| /* ==================================================================== |
| 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.storage; |
| |
| import org.apache.poi.poifs.common.POIFSConstants; |
| import org.apache.poi.util.IOUtils; |
| import org.apache.poi.util.POILogFactory; |
| import org.apache.poi.util.POILogger; |
| |
| import java.io.*; |
| |
| /** |
| * A big block created from an InputStream, holding the raw data |
| * |
| * @author Marc Johnson (mjohnson at apache dot org |
| */ |
| |
| public class RawDataBlock |
| implements ListManagedBlock |
| { |
| private byte[] _data; |
| private boolean _eof; |
| private boolean _hasData; |
| private static POILogger log = POILogFactory.getLogger(RawDataBlock.class); |
| |
| /** |
| * Constructor RawDataBlock |
| * |
| * @param stream the InputStream from which the data will be read |
| * |
| * @exception IOException on I/O errors, and if an insufficient |
| * amount of data is read (the InputStream must |
| * be an exact multiple of the block size) |
| */ |
| public RawDataBlock(final InputStream stream) |
| throws IOException { |
| this(stream, POIFSConstants.BIG_BLOCK_SIZE); |
| } |
| /** |
| * Constructor RawDataBlock |
| * |
| * @param stream the InputStream from which the data will be read |
| * @param blockSize the size of the POIFS blocks, normally 512 bytes {@link POIFSConstants#BIG_BLOCK_SIZE} |
| * |
| * @exception IOException on I/O errors, and if an insufficient |
| * amount of data is read (the InputStream must |
| * be an exact multiple of the block size) |
| */ |
| public RawDataBlock(final InputStream stream, int blockSize) |
| throws IOException { |
| _data = new byte[ blockSize ]; |
| int count = IOUtils.readFully(stream, _data); |
| _hasData = (count > 0); |
| |
| if (count == -1) { |
| _eof = true; |
| } |
| else if (count != blockSize) { |
| // IOUtils.readFully will always read the |
| // requested number of bytes, unless it hits |
| // an EOF |
| _eof = true; |
| String type = " byte" + ((count == 1) ? ("") |
| : ("s")); |
| |
| log.log(POILogger.ERROR, |
| "Unable to read entire block; " + count |
| + type + " read before EOF; expected " |
| + blockSize + " bytes. Your document " |
| + "was either written by software that " |
| + "ignores the spec, or has been truncated!" |
| ); |
| } |
| else { |
| _eof = false; |
| } |
| } |
| |
| /** |
| * When we read the data, did we hit end of file? |
| * |
| * @return true if the EoF was hit during this block, or |
| * false if not. If you have a dodgy short last block, then |
| * it's possible to both have data, and also hit EoF... |
| */ |
| public boolean eof() { |
| return _eof; |
| } |
| /** |
| * Did we actually find any data to read? It's possible, |
| * in the event of a short last block, to both have hit |
| * the EoF, but also to have data |
| */ |
| public boolean hasData() { |
| return _hasData; |
| } |
| |
| /* ********** START implementation of ListManagedBlock ********** */ |
| |
| /** |
| * Get the data from the block |
| * |
| * @return the block's data as a byte array |
| * |
| * @exception IOException if there is no data |
| */ |
| public byte [] getData() |
| throws IOException |
| { |
| if (! hasData()) |
| { |
| throw new IOException("Cannot return empty data"); |
| } |
| return _data; |
| } |
| |
| /* ********** END implementation of ListManagedBlock ********** */ |
| } // end public class RawDataBlock |
| |