com.twelvemonkeys.imageio.stream.SubImageInputStream Maven / Gradle / Ivy
/*
* Copyright (c) 2009, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.twelvemonkeys.imageio.stream;
import com.twelvemonkeys.lang.Validate;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageInputStreamImpl;
import java.io.IOException;
/**
* A wrapper for {@link ImageInputStream} to limit the number of bytes that can be read.
*
* @author Harald Kuhr
* @author last modified by $Author: haraldk$
* @version $Id: SubImageInputStream.java,v 1.0 Nov 8, 2009 2:50:58 PM haraldk Exp$
*/
public final class SubImageInputStream extends ImageInputStreamImpl {
// NOTE: This class is based on com.sun.imageio.plugins.common.SubImageInputStream, but fixes some of its bugs.
private final ImageInputStream stream;
private final long startPos;
private final long length;
/**
* Creates a {@link ImageInputStream}, reading up to a maximum number of bytes from the underlying stream.
*
* @param pStream the underlying stream
* @param pLength the maximum length to read from the stream.
* Note that {@code pStream} may contain less than this maximum number of bytes.
*
* @throws IOException if {@code pStream}'s position can't be determined.
* @throws IllegalArgumentException if {@code pStream == null} or {@code pLength < 0}
*/
public SubImageInputStream(final ImageInputStream pStream, final long pLength) throws IOException {
Validate.notNull(pStream, "stream");
Validate.isTrue(pLength >= 0, pLength, "length < 0: %d");
stream = pStream;
startPos = pStream.getStreamPosition();
length = pLength;
}
public int read() throws IOException {
if (streamPos >= length) { // Local EOF
return -1;
}
else {
int read = stream.read();
if (read >= 0) {
streamPos++;
}
return read;
}
}
public int read(final byte[] pBytes, final int pOffset, final int pLength) throws IOException {
if (streamPos >= length) { // Local EOF
return -1;
}
// Safe cast, as pLength can never cause int overflow
int length = (int) Math.min(pLength, this.length - streamPos);
int count = stream.read(pBytes, pOffset, length);
if (count >= 0) {
streamPos += count;
}
return count;
}
@Override
public long length() {
try {
long length = stream.length();
return length < 0 ? -1 : Math.min(length - startPos, this.length);
}
catch (IOException ignore) {
}
return -1;
}
@Override
public void seek(final long pPosition) throws IOException {
if (pPosition < getFlushedPosition()) {
throw new IndexOutOfBoundsException("pos < flushedPosition");
}
stream.seek(startPos + pPosition);
streamPos = pPosition;
}
@SuppressWarnings({"FinalizeDoesntCallSuperFinalize"})
@Override
protected void finalize() throws Throwable {
// Empty finalizer (for improved performance; no need to call super.finalize() in this case)
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy