net.markenwerk.utils.data.fetcher.BufferedDataFetcher Maven / Gradle / Ivy
/*
* Copyright (c) 2015, 2016 Torsten Krause, Markenwerk GmbH
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package net.markenwerk.utils.data.fetcher;
import java.io.InputStream;
import java.io.OutputStream;
/**
* {@link AbstractBufferedDataFetcher} is a sensible base implementation of
* {@link DataFetcher} that uses a {@code byte[]} as buffer, while copying all
* bytes from an {@link InputStream} to an {@link OutputStream} by sequentially
* reading from the {@link InputStream} into the buffer and then writing from
* the buffer to the {@link OutputStream}.
*
*
* The buffer is eagerly allocated in the constructor just once and then used
* for every operation. A {@link BufferedDataFetcher} is therefore not
* threadsafe.
*
*
* After a buffer has been used, it is overwritten with zeros, to remove any
* buffered information from the memory.
*
* @author Torsten Krause (tk at markenwerk dot net)
* @since 4.0.0
*/
public final class BufferedDataFetcher extends AbstractBufferedDataFetcher {
private final byte[] buffer;
/**
* Creates a new {@link BufferedDataFetcher} with the default buffer size of
* 1024 bytes.
*/
public BufferedDataFetcher() {
this(DEFAULT_BUFEFR_SIZE);
}
/**
* Creates a new {@link BufferedDataFetcher} with the given buffer size.
*
* @param bufferSize
* The buffer size.
*/
public BufferedDataFetcher(int bufferSize) {
buffer = createBuffer(bufferSize);
}
@Override
protected byte[] obtainBuffer() {
return buffer;
}
@Override
protected void returnBuffer(byte[] buffer) {
cleanBuffer();
}
private void cleanBuffer() {
for (int i = 0, n = buffer.length; i < n; i++) {
buffer[i] = 0;
}
}
}