123 lines
3.8 KiB
Java
123 lines
3.8 KiB
Java
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/* ====================================================================
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Licensed to the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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this work for additional information regarding copyright ownership.
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The ASF licenses this file to You under the Apache License, Version 2.0
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(the "License"); you may not use this file except in compliance with
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the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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==================================================================== */
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package org.apache.poi.poifs.storage;
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import org.apache.poi.poifs.common.POIFSConstants;
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import org.apache.poi.util.IOUtils;
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import java.io.*;
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/**
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* A big block created from an InputStream, holding the raw data
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*
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* @author Marc Johnson (mjohnson at apache dot org
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*/
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public class RawDataBlock
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implements ListManagedBlock
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{
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private byte[] _data;
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private boolean _eof;
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/**
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* Constructor RawDataBlock
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*
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* @param stream the InputStream from which the data will be read
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*
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* @exception IOException on I/O errors, and if an insufficient
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* amount of data is read (the InputStream must
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* be an exact multiple of the block size)
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*/
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public RawDataBlock(final InputStream stream)
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throws IOException {
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this(stream, POIFSConstants.BIG_BLOCK_SIZE);
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}
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/**
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* Constructor RawDataBlock
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*
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* @param stream the InputStream from which the data will be read
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* @param blockSize the size of the POIFS blocks, normally 512 bytes {@link POIFSConstants#BIG_BLOCK_SIZE}
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*
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* @exception IOException on I/O errors, and if an insufficient
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* amount of data is read (the InputStream must
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* be an exact multiple of the block size)
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*/
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public RawDataBlock(final InputStream stream, int blockSize)
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throws IOException {
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_data = new byte[ blockSize ];
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int count = IOUtils.readFully(stream, _data);
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if (count == -1) {
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_eof = true;
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}
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else if (count != blockSize) {
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// IOUtils.readFully will always read the
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// requested number of bytes, unless it hits
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// an EOF
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_eof = true;
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String type = " byte" + ((count == 1) ? ("")
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: ("s"));
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throw new IOException("Unable to read entire block; " + count
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+ type + " read before EOF; expected "
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+ blockSize + " bytes");
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}
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else {
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_eof = false;
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}
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}
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/**
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* When we read the data, did we hit end of file?
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*
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* @return true if no data was read because we were at the end of
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* the file, else false
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*
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* @exception IOException
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*/
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public boolean eof()
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throws IOException
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{
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return _eof;
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}
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/* ********** START implementation of ListManagedBlock ********** */
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/**
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* Get the data from the block
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*
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* @return the block's data as a byte array
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*
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* @exception IOException if there is no data
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*/
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public byte [] getData()
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throws IOException
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{
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if (eof())
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{
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throw new IOException("Cannot return empty data");
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}
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return _data;
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}
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/* ********** END implementation of ListManagedBlock ********** */
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} // end public class RawDataBlock
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