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78596d7891
git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1884262 13f79535-47bb-0310-9956-ffa450edef68
520 lines
20 KiB
Java
520 lines
20 KiB
Java
/* ====================================================================
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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.util;
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import java.io.ByteArrayOutputStream;
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import java.io.Closeable;
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import java.io.EOFException;
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import java.io.File;
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import java.io.FileOutputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.OutputStream;
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import java.io.PushbackInputStream;
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import java.nio.ByteBuffer;
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import java.nio.channels.ReadableByteChannel;
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import java.util.Arrays;
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import java.util.zip.CRC32;
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import java.util.zip.Checksum;
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import org.apache.poi.EmptyFileException;
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@Internal
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public final class IOUtils {
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private static final POILogger logger = POILogFactory.getLogger( IOUtils.class );
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/**
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* The default buffer size to use for the skip() methods.
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*/
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private static final int SKIP_BUFFER_SIZE = 2048;
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private static byte[] SKIP_BYTE_BUFFER;
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/**
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* The current set global allocation limit override,
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* -1 means limits are applied per record type.
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*/
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private static int BYTE_ARRAY_MAX_OVERRIDE = -1;
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private IOUtils() {
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// no instances of this class
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}
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/**
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* If this value is set to > 0, {@link #safelyAllocate(long, int)} will ignore the
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* maximum record length parameter.
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*
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* This is designed to allow users to bypass the hard-coded maximum record lengths
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* if they are willing to accept the risk of allocating memory up to the size specified.
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*
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* It also allows to impose a lower limit than used for very memory constrained systems.
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*
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* Note: This is an per-allocation limit and does not allow to limit overall sum of allocations!
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*
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* Use -1 for using the limits specified per record-type.
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*
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* @param maxOverride The maximum number of bytes that should be possible to be allocated in one step.
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* @since 4.0.0
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*/
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@SuppressWarnings("unused")
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public static void setByteArrayMaxOverride(int maxOverride) {
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BYTE_ARRAY_MAX_OVERRIDE = maxOverride;
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}
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/**
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* Peeks at the first 8 bytes of the stream. Returns those bytes, but
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* with the stream unaffected. Requires a stream that supports mark/reset,
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* or a PushbackInputStream. If the stream has >0 but <8 bytes,
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* remaining bytes will be zero.
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* @throws EmptyFileException if the stream is empty
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*/
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public static byte[] peekFirst8Bytes(InputStream stream) throws IOException, EmptyFileException {
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return peekFirstNBytes(stream, 8);
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}
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private static void checkByteSizeLimit(int length) {
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if(BYTE_ARRAY_MAX_OVERRIDE != -1 && length > BYTE_ARRAY_MAX_OVERRIDE) {
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throwRFE(length, BYTE_ARRAY_MAX_OVERRIDE);
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}
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}
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/**
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* Peeks at the first N bytes of the stream. Returns those bytes, but
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* with the stream unaffected. Requires a stream that supports mark/reset,
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* or a PushbackInputStream. If the stream has >0 but <N bytes,
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* remaining bytes will be zero.
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* @throws EmptyFileException if the stream is empty
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*/
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public static byte[] peekFirstNBytes(InputStream stream, int limit) throws IOException, EmptyFileException {
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checkByteSizeLimit(limit);
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stream.mark(limit);
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ByteArrayOutputStream bos = new ByteArrayOutputStream(limit);
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copy(new BoundedInputStream(stream, limit), bos);
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int readBytes = bos.size();
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if (readBytes == 0) {
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throw new EmptyFileException();
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}
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if (readBytes < limit) {
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bos.write(new byte[limit-readBytes]);
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}
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byte[] peekedBytes = bos.toByteArray();
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if(stream instanceof PushbackInputStream) {
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PushbackInputStream pin = (PushbackInputStream)stream;
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pin.unread(peekedBytes, 0, readBytes);
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} else {
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stream.reset();
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}
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return peekedBytes;
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}
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/**
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* Reads all the data from the input stream, and returns the bytes read.
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*
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* @param stream The byte stream of data to read.
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* @return A byte array with the read bytes.
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* @throws IOException If reading data fails or EOF is encountered too early for the given length.
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*/
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public static byte[] toByteArray(InputStream stream) throws IOException {
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return toByteArray(stream, Integer.MAX_VALUE);
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}
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/**
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* Reads up to {@code length} bytes from the input stream, and returns the bytes read.
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*
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* @param stream The byte stream of data to read.
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* @param length The maximum length to read, use Integer.MAX_VALUE to read the stream
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* until EOF.
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* @return A byte array with the read bytes.
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* @throws IOException If reading data fails or EOF is encountered too early for the given length.
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*/
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public static byte[] toByteArray(InputStream stream, final int length) throws IOException {
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return toByteArray(stream, length, Integer.MAX_VALUE);
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}
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/**
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* Reads up to {@code length} bytes from the input stream, and returns the bytes read.
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*
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* @param stream The byte stream of data to read.
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* @param length The maximum length to read, use {@link Integer#MAX_VALUE} to read the stream
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* until EOF
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* @param maxLength if the input is equal to/longer than {@code maxLength} bytes,
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* then throw an {@link IOException} complaining about the length.
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* use {@link Integer#MAX_VALUE} to disable the check
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* @return A byte array with the read bytes.
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* @throws IOException If reading data fails or EOF is encountered too early for the given length.
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*/
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public static byte[] toByteArray(InputStream stream, final long length, final int maxLength) throws IOException {
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if (length < 0L || maxLength < 0L) {
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throw new RecordFormatException("Can't allocate an array of length < 0");
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}
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if (length > (long)Integer.MAX_VALUE) {
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throw new RecordFormatException("Can't allocate an array > "+Integer.MAX_VALUE);
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}
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if ((length != Integer.MAX_VALUE) || (maxLength != Integer.MAX_VALUE)) {
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checkLength(length, maxLength);
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}
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final int len = Math.min((int)length, maxLength);
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ByteArrayOutputStream baos = new ByteArrayOutputStream(len == Integer.MAX_VALUE ? 4096 : len);
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byte[] buffer = new byte[4096];
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int totalBytes = 0, readBytes;
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do {
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readBytes = stream.read(buffer, 0, Math.min(buffer.length, len-totalBytes));
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totalBytes += Math.max(readBytes,0);
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if (readBytes > 0) {
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baos.write(buffer, 0, readBytes);
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}
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checkByteSizeLimit(totalBytes);
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} while (totalBytes < len && readBytes > -1);
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if (maxLength != Integer.MAX_VALUE && totalBytes == maxLength) {
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throw new IOException("MaxLength ("+maxLength+") reached - stream seems to be invalid.");
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}
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if (len != Integer.MAX_VALUE && totalBytes < len) {
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throw new EOFException("unexpected EOF - expected len: "+len+" - actual len: "+totalBytes);
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}
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return baos.toByteArray();
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}
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private static void checkLength(long length, int maxLength) {
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if (BYTE_ARRAY_MAX_OVERRIDE > 0) {
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if (length > BYTE_ARRAY_MAX_OVERRIDE) {
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throwRFE(length, BYTE_ARRAY_MAX_OVERRIDE);
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}
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} else if (length > maxLength) {
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throwRFE(length, maxLength);
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}
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}
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/**
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* Returns an array (that shouldn't be written to!) of the
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* ByteBuffer. Will be of the requested length, or possibly
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* longer if that's easier.
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*/
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public static byte[] toByteArray(ByteBuffer buffer, int length) {
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if(buffer.hasArray() && buffer.arrayOffset() == 0) {
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// The backing array should work out fine for us
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return buffer.array();
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}
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checkByteSizeLimit(length);
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byte[] data = new byte[length];
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buffer.get(data);
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return data;
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}
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/**
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* Helper method, just calls <tt>readFully(in, b, 0, b.length)</tt>
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*/
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public static int readFully(InputStream in, byte[] b) throws IOException {
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return readFully(in, b, 0, b.length);
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}
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/**
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* <p>Same as the normal {@link InputStream#read(byte[], int, int)}, but tries to ensure
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* that the entire len number of bytes is read.</p>
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*
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* <p>If the end of file is reached before any bytes are read, returns <tt>-1</tt>. If
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* the end of the file is reached after some bytes are read, returns the
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* number of bytes read. If the end of the file isn't reached before <tt>len</tt>
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* bytes have been read, will return <tt>len</tt> bytes.</p>
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*
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* @param in the stream from which the data is read.
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* @param b the buffer into which the data is read.
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* @param off the start offset in array <tt>b</tt> at which the data is written.
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* @param len the maximum number of bytes to read.
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*/
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public static int readFully(InputStream in, byte[] b, int off, int len) throws IOException {
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int total = 0;
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while (true) {
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int got = in.read(b, off + total, len - total);
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if (got < 0) {
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return (total == 0) ? -1 : total;
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}
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total += got;
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if (total == len) {
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return total;
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}
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}
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}
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/**
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* Same as the normal <tt>channel.read(b)</tt>, but tries to ensure
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* that the buffer is filled completely if possible, i.e. b.remaining()
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* returns 0.
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* <p>
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* If the end of file is reached before any bytes are read, returns -1. If
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* the end of the file is reached after some bytes are read, returns the
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* number of bytes read. If the end of the file isn't reached before the
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* buffer has no more remaining capacity, will return the number of bytes
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* that were read.
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*/
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public static int readFully(ReadableByteChannel channel, ByteBuffer b) throws IOException {
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int total = 0;
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while (true) {
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int got = channel.read(b);
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if (got < 0) {
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return (total == 0) ? -1 : total;
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}
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total += got;
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if (total == b.capacity() || b.position() == b.capacity()) {
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return total;
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}
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}
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}
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/**
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* Copies all the data from the given InputStream to the OutputStream. It
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* leaves both streams open, so you will still need to close them once done.
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*
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* @param inp The {@link InputStream} which provides the data
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* @param out The {@link OutputStream} to write the data to
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* @return the amount of bytes copied
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*
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* @throws IOException If copying the data fails.
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*/
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public static long copy(InputStream inp, OutputStream out) throws IOException {
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return copy(inp, out, -1);
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}
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/**
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* Copies all the data from the given InputStream to the OutputStream. It
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* leaves both streams open, so you will still need to close them once done.
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*
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* @param inp The {@link InputStream} which provides the data
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* @param out The {@link OutputStream} to write the data to
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* @param limit limit the copied bytes - use {@code -1} for no limit
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* @return the amount of bytes copied
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*
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* @throws IOException If copying the data fails.
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*/
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public static long copy(InputStream inp, OutputStream out, long limit) throws IOException {
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final byte[] buff = new byte[4096];
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long totalCount = 0;
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int readBytes = -1;
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do {
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int todoBytes = (int)((limit < 0) ? buff.length : Math.min(limit-totalCount, buff.length));
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if (todoBytes > 0) {
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readBytes = inp.read(buff, 0, todoBytes);
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if (readBytes > 0) {
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out.write(buff, 0, readBytes);
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totalCount += readBytes;
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}
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}
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} while (readBytes >= 0 && (limit == -1 || totalCount < limit));
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return totalCount;
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}
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/**
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* Copy the contents of the stream to a new file.
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*
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* @param srcStream The {@link InputStream} which provides the data
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* @param destFile The file where the data should be stored
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* @return the amount of bytes copied
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*
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* @throws IOException If the target directory does not exist and cannot be created
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* or if copying the data fails.
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*/
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public static long copy(InputStream srcStream, File destFile) throws IOException {
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File destDirectory = destFile.getParentFile();
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if (!(destDirectory.exists() || destDirectory.mkdirs())) {
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throw new RuntimeException("Can't create destination directory: "+destDirectory);
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}
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try (OutputStream destStream = new FileOutputStream(destFile)) {
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return IOUtils.copy(srcStream, destStream);
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}
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}
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/**
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* Calculate checksum on input data
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*/
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public static long calculateChecksum(byte[] data) {
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Checksum sum = new CRC32();
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sum.update(data, 0, data.length);
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return sum.getValue();
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}
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/**
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* Calculate checksum on all the data read from input stream.
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*
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* This should be more efficient than the equivalent code
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* {@code IOUtils.calculateChecksum(IOUtils.toByteArray(stream))}
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*/
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public static long calculateChecksum(InputStream stream) throws IOException {
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Checksum sum = new CRC32();
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byte[] buf = new byte[4096];
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int count;
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while ((count = stream.read(buf)) != -1) {
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if (count > 0) {
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sum.update(buf, 0, count);
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}
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}
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return sum.getValue();
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}
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/**
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* Quietly (no exceptions) close Closable resource. In case of error it will
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* be printed to {@link IOUtils} class logger.
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*
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* @param closeable
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* resource to close
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*/
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public static void closeQuietly( final Closeable closeable ) {
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// no need to log a NullPointerException here
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if(closeable == null) {
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return;
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}
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try {
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closeable.close();
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} catch ( Exception exc ) {
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logger.log( POILogger.ERROR, "Unable to close resource: " + exc,
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exc );
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}
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}
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/**
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* Skips bytes from an input byte stream.
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* This implementation guarantees that it will read as many bytes
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* as possible before giving up; this may not always be the case for
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* skip() implementations in subclasses of {@link InputStream}.
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* <p>
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* Note that the implementation uses {@link InputStream#read(byte[], int, int)} rather
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* than delegating to {@link InputStream#skip(long)}.
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* This means that the method may be considerably less efficient than using the actual skip implementation,
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* this is done to guarantee that the correct number of bytes are skipped.
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* </p>
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* <p>
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* This mimics POI's {@link #readFully(InputStream, byte[])}.
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* If the end of file is reached before any bytes are read, returns <tt>-1</tt>. If
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* the end of the file is reached after some bytes are read, returns the
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* number of bytes read. If the end of the file isn't reached before <tt>len</tt>
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* bytes have been read, will return <tt>len</tt> bytes.</p>
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* </p>
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* <p>
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* Copied nearly verbatim from commons-io 41a3e9c
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* </p>
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*
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* @param input byte stream to skip
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* @param toSkip number of bytes to skip.
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* @return number of bytes actually skipped.
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* @throws IOException if there is a problem reading the file
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* @throws IllegalArgumentException if toSkip is negative
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* @see InputStream#skip(long)
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*
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*/
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public static long skipFully(final InputStream input, final long toSkip) throws IOException {
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if (toSkip < 0) {
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throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
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}
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if (toSkip == 0) {
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return 0L;
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}
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/*
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* N.B. no need to synchronize this because: - we don't care if the buffer is created multiple times (the data
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* is ignored) - we always use the same size buffer, so if it it is recreated it will still be OK (if the buffer
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* size were variable, we would need to synch. to ensure some other thread did not create a smaller one)
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*/
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if (SKIP_BYTE_BUFFER == null) {
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SKIP_BYTE_BUFFER = new byte[SKIP_BUFFER_SIZE];
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}
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long remain = toSkip;
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while (remain > 0) {
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// See https://issues.apache.org/jira/browse/IO-203 for why we use read() rather than delegating to skip()
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final long n = input.read(SKIP_BYTE_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
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if (n < 0) { // EOF
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break;
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}
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remain -= n;
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}
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if (toSkip == remain) {
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return -1L;
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}
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return toSkip - remain;
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}
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public static byte[] safelyAllocate(long length, int maxLength) {
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safelyAllocateCheck(length, maxLength);
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checkByteSizeLimit((int)length);
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return new byte[(int)length];
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}
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public static void safelyAllocateCheck(long length, int maxLength) {
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if (length < 0L) {
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throw new RecordFormatException("Can't allocate an array of length < 0, but had " + length + " and " + maxLength);
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}
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if (length > (long)Integer.MAX_VALUE) {
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throw new RecordFormatException("Can't allocate an array > "+Integer.MAX_VALUE);
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}
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checkLength(length, maxLength);
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}
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public static byte[] safelyClone(byte[] src, int offset, int length, int maxLength) {
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if (src == null) {
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return null;
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}
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assert(offset >= 0 && length >= 0 && maxLength >= 0);
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safelyAllocateCheck(Math.min(src.length-offset,length), maxLength);
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return Arrays.copyOfRange(src, offset, offset+length);
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}
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/**
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* Simple utility function to check that you haven't hit EOF
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* when reading a byte.
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*
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* @param is inputstream to read
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* @return byte read, unless
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* @throws IOException on IOException or EOF if -1 is read
|
|
*/
|
|
public static int readByte(InputStream is) throws IOException {
|
|
int b = is.read();
|
|
if (b == -1) {
|
|
throw new EOFException();
|
|
}
|
|
return b;
|
|
}
|
|
|
|
private static void throwRFE(long length, int maxLength) {
|
|
throw new RecordFormatException("Tried to allocate an array of length "+length +
|
|
", but "+ maxLength+" is the maximum for this record type.\n" +
|
|
"If the file is not corrupt, please open an issue on bugzilla to request \n" +
|
|
"increasing the maximum allowable size for this record type.\n"+
|
|
"As a temporary workaround, consider setting a higher override value with " +
|
|
"IOUtils.setByteArrayMaxOverride()");
|
|
|
|
}
|
|
}
|