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/* * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.util.zip; import java.io.FilterOutputStream; import java.io.OutputStream; import java.io.InputStream; import java.io.IOException; /** * This class implements an output stream filter for compressing data in * the "deflate" compression format. It is also used as the basis for other * types of compression filters, such as GZIPOutputStream. * * @see Deflater * @author David Connelly * @since 1.1 */ public class DeflaterOutputStream extends FilterOutputStream { /** * Compressor for this stream. */ protected Deflater def; /** * Output buffer for writing compressed data. */ protected byte[] buf; /** * Indicates that the stream has been closed. */ private boolean closed = false; private final boolean syncFlush; /** * Creates a new output stream with the specified compressor, * buffer size and flush mode. * * @param out the output stream * @param def the compressor ("deflater") * @param size the output buffer size * @param syncFlush * if {@code true} the {@link #flush()} method of this * instance flushes the compressor with flush mode * {@link Deflater#SYNC_FLUSH} before flushing the output * stream, otherwise only flushes the output stream * * @throws IllegalArgumentException if {@code size <= 0} * * @since 1.7 */ public DeflaterOutputStream(OutputStream out, Deflater def, int size, boolean syncFlush) { super(out); if (out == null || def == null) { throw new NullPointerException(); } else if (size <= 0) { throw new IllegalArgumentException("buffer size <= 0"); } this.def = def; this.buf = new byte[size]; this.syncFlush = syncFlush; } /** * Creates a new output stream with the specified compressor and * buffer size. * * <p>The new output stream instance is created as if by invoking * the 4-argument constructor DeflaterOutputStream(out, def, size, false). * * @param out the output stream * @param def the compressor ("deflater") * @param size the output buffer size * @exception IllegalArgumentException if {@code size <= 0} */ public DeflaterOutputStream(OutputStream out, Deflater def, int size) { this(out, def, size, false); } /** * Creates a new output stream with the specified compressor, flush * mode and a default buffer size. * * @param out the output stream * @param def the compressor ("deflater") * @param syncFlush * if {@code true} the {@link #flush()} method of this * instance flushes the compressor with flush mode * {@link Deflater#SYNC_FLUSH} before flushing the output * stream, otherwise only flushes the output stream * * @since 1.7 */ public DeflaterOutputStream(OutputStream out, Deflater def, boolean syncFlush) { this(out, def, 512, syncFlush); } /** * Creates a new output stream with the specified compressor and * a default buffer size. * * <p>The new output stream instance is created as if by invoking * the 3-argument constructor DeflaterOutputStream(out, def, false). * * @param out the output stream * @param def the compressor ("deflater") */ public DeflaterOutputStream(OutputStream out, Deflater def) { this(out, def, 512, false); } boolean usesDefaultDeflater = false; /** * Creates a new output stream with a default compressor, a default * buffer size and the specified flush mode. * * @param out the output stream * @param syncFlush * if {@code true} the {@link #flush()} method of this * instance flushes the compressor with flush mode * {@link Deflater#SYNC_FLUSH} before flushing the output * stream, otherwise only flushes the output stream * * @since 1.7 */ public DeflaterOutputStream(OutputStream out, boolean syncFlush) { this(out, new Deflater(), 512, syncFlush); usesDefaultDeflater = true; } /** * Creates a new output stream with a default compressor and buffer size. * * <p>The new output stream instance is created as if by invoking * the 2-argument constructor DeflaterOutputStream(out, false). * * @param out the output stream */ public DeflaterOutputStream(OutputStream out) { this(out, false); usesDefaultDeflater = true; } /** * Writes a byte to the compressed output stream. This method will * block until the byte can be written. * @param b the byte to be written * @exception IOException if an I/O error has occurred */ public void write(int b) throws IOException { byte[] buf = new byte[1]; buf[0] = (byte) (b & 0xff); write(buf, 0, 1); } /** * Writes an array of bytes to the compressed output stream. This * method will block until all the bytes are written. * @param b the data to be written * @param off the start offset of the data * @param len the length of the data * @exception IOException if an I/O error has occurred */ public void write(byte[] b, int off, int len) throws IOException { if (def.finished()) { throw new IOException("write beyond end of stream"); } if ((off | len | (off + len) | (b.length - (off + len))) < 0) { throw new IndexOutOfBoundsException(); } else if (len == 0) { return; } if (!def.finished()) { def.setInput(b, off, len); while (!def.needsInput()) { deflate(); } } } /** * Finishes writing compressed data to the output stream without closing * the underlying stream. Use this method when applying multiple filters * in succession to the same output stream. * @exception IOException if an I/O error has occurred */ public void finish() throws IOException { if (!def.finished()) { def.finish(); while (!def.finished()) { deflate(); } } } /** * Writes remaining compressed data to the output stream and closes the * underlying stream. * @exception IOException if an I/O error has occurred */ public void close() throws IOException { if (!closed) { finish(); if (usesDefaultDeflater) def.end(); out.close(); closed = true; } } /** * Writes next block of compressed data to the output stream. * @throws IOException if an I/O error has occurred */ protected void deflate() throws IOException { int len = def.deflate(buf, 0, buf.length); if (len > 0) { out.write(buf, 0, len); } } /** * Flushes the compressed output stream. * * If {@link #DeflaterOutputStream(OutputStream, Deflater, int, boolean) * syncFlush} is {@code true} when this compressed output stream is * constructed, this method first flushes the underlying {@code compressor} * with the flush mode {@link Deflater#SYNC_FLUSH} to force * all pending data to be flushed out to the output stream and then * flushes the output stream. Otherwise this method only flushes the * output stream without flushing the {@code compressor}. * * @throws IOException if an I/O error has occurred * * @since 1.7 */ public void flush() throws IOException { if (syncFlush && !def.finished()) { int len = 0; while ((len = def.deflate(buf, 0, buf.length, Deflater.SYNC_FLUSH)) > 0) { out.write(buf, 0, len); if (len < buf.length) break; } } out.flush(); } }