Java tutorial
/** * Copyright 2013 Netflix, Inc. * * Licensed 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 c3.ops.priam.compress; import org.apache.commons.io.IOUtils; import org.xerial.snappy.SnappyOutputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.Iterator; /** * Byte iterator representing compressed data. * Uses snappy compression */ public class ChunkedStream implements Iterator<byte[]> { private static int BYTES_TO_READ = 2048; private boolean hasnext = true; private ByteArrayOutputStream bos; private SnappyOutputStream compress; // private BufferedOutputStream compress; private InputStream origin; private long chunkSize; public ChunkedStream(InputStream is, long chunkSize) throws IOException { this.origin = is; this.bos = new ByteArrayOutputStream(); this.compress = new SnappyOutputStream(bos); // this.compress = new BufferedOutputStream(bos); this.chunkSize = chunkSize; } @Override public boolean hasNext() { return hasnext; } @Override public byte[] next() { try { byte data[] = new byte[BYTES_TO_READ]; int count; while ((count = origin.read(data, 0, data.length)) != -1) { compress.write(data, 0, count); if (bos.size() >= chunkSize) return returnSafe(); } // We don't have anything else to read hence set to false. return done(); } catch (IOException e) { throw new RuntimeException(e); } } private byte[] done() throws IOException { compress.flush(); byte[] return_ = bos.toByteArray(); hasnext = false; IOUtils.closeQuietly(compress); IOUtils.closeQuietly(bos); IOUtils.closeQuietly(origin); return return_; } private byte[] returnSafe() throws IOException { byte[] return_ = bos.toByteArray(); bos.reset(); return return_; } @Override public void remove() { } }