| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 java.util.zip; |
| |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * An {@code InputStream} filter to compress data. Callers read |
| * compressed data in the "deflate" format from the uncompressed |
| * underlying stream. |
| * @since 1.6 |
| */ |
| public class DeflaterInputStream extends FilterInputStream { |
| private static final int DEFAULT_BUFFER_SIZE = 1024; |
| |
| protected final Deflater def; |
| protected final byte[] buf; |
| |
| private boolean closed = false; |
| private boolean available = true; |
| |
| /** |
| * Constructs a {@code DeflaterInputStream} with a new {@code Deflater} and an |
| * implementation-defined default internal buffer size. {@code in} is a source of |
| * uncompressed data, and this stream will be a source of compressed data. |
| * |
| * @param in the source {@code InputStream} |
| */ |
| public DeflaterInputStream(InputStream in) { |
| this(in, new Deflater(), DEFAULT_BUFFER_SIZE); |
| } |
| |
| /** |
| * Constructs a {@code DeflaterInputStream} with the given {@code Deflater} and an |
| * implementation-defined default internal buffer size. {@code in} is a source of |
| * uncompressed data, and this stream will be a source of compressed data. |
| * |
| * @param in the source {@code InputStream} |
| * @param deflater the {@code Deflater} to be used for compression |
| */ |
| public DeflaterInputStream(InputStream in, Deflater deflater) { |
| this(in, deflater, DEFAULT_BUFFER_SIZE); |
| } |
| |
| /** |
| * Constructs a {@code DeflaterInputStream} with the given {@code Deflater} and |
| * given internal buffer size. {@code in} is a source of |
| * uncompressed data, and this stream will be a source of compressed data. |
| * |
| * @param in the source {@code InputStream} |
| * @param deflater the {@code Deflater} to be used for compression |
| * @param bufferSize the length in bytes of the internal buffer |
| */ |
| public DeflaterInputStream(InputStream in, Deflater deflater, int bufferSize) { |
| super(in); |
| if (in == null || deflater == null) { |
| throw new NullPointerException(); |
| } |
| if (bufferSize <= 0) { |
| throw new IllegalArgumentException(); |
| } |
| this.def = deflater; |
| this.buf = new byte[bufferSize]; |
| } |
| |
| /** |
| * Closes the underlying input stream and discards any remaining uncompressed |
| * data. |
| */ |
| @Override |
| public void close() throws IOException { |
| closed = true; |
| def.end(); |
| in.close(); |
| } |
| |
| /** |
| * Reads a byte from the compressed input stream. The result will be a byte of compressed |
| * data corresponding to an uncompressed byte or bytes read from the underlying stream. |
| * |
| * @return the byte or -1 if the end of the stream has been reached. |
| */ |
| @Override |
| public int read() throws IOException { |
| byte[] result = new byte[1]; |
| if (read(result, 0, 1) == -1) { |
| return -1; |
| } |
| return result[0] & 0xff; |
| } |
| |
| /** |
| * Reads compressed data into a byte buffer. The result will be bytes of compressed |
| * data corresponding to an uncompressed byte or bytes read from the underlying stream. |
| * |
| * @param b |
| * the byte buffer that compressed data will be read into. |
| * @param off |
| * the offset in the byte buffer where compressed data will start |
| * to be read into. |
| * @param len |
| * the length of the compressed data that is expected to read. |
| * @return the number of bytes read or -1 if the end of the compressed input |
| * stream has been reached. |
| */ |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| checkClosed(); |
| if (b == null) { |
| throw new NullPointerException(); |
| } |
| if (off < 0 || len < 0 || len > b.length - off) { |
| throw new IndexOutOfBoundsException(); |
| } |
| if (len == 0) { |
| return 0; |
| } |
| |
| if (!available) { |
| return -1; |
| } |
| |
| int count = 0; |
| while (count < len && !def.finished()) { |
| if (def.needsInput()) { |
| // read data from input stream |
| int byteCount = in.read(buf); |
| if (byteCount == -1) { |
| def.finish(); |
| } else { |
| def.setInput(buf, 0, byteCount); |
| } |
| } |
| int byteCount = def.deflate(buf, 0, Math.min(buf.length, len - count)); |
| if (byteCount == -1) { |
| break; |
| } |
| System.arraycopy(buf, 0, b, off + count, byteCount); |
| count += byteCount; |
| } |
| if (count == 0) { |
| count = -1; |
| available = false; |
| } |
| return count; |
| } |
| |
| /** |
| * {@inheritDoc} |
| * <p>Note: if {@code n > Integer.MAX_VALUE}, this stream will only attempt to |
| * skip {@code Integer.MAX_VALUE} bytes. |
| */ |
| @Override |
| public long skip(long n) throws IOException { |
| if (n < 0) { |
| throw new IllegalArgumentException(); |
| } |
| if (n > Integer.MAX_VALUE) { |
| n = Integer.MAX_VALUE; |
| } |
| checkClosed(); |
| |
| int remaining = (int) n; |
| byte[] tmp = new byte[Math.min(remaining, DEFAULT_BUFFER_SIZE)]; |
| while (remaining > 0) { |
| int count = read(tmp, 0, Math.min(remaining, tmp.length)); |
| if (count == -1) { |
| break; |
| } |
| remaining -= count; |
| } |
| return n - remaining; |
| } |
| |
| /** |
| * Returns 0 when when this stream has exhausted its input; and 1 otherwise. |
| * A result of 1 does not guarantee that further bytes can be returned, |
| * with or without blocking. |
| * |
| * <p>Although consistent with the RI, this behavior is inconsistent with |
| * {@link InputStream#available()}, and violates the <a |
| * href="http://en.wikipedia.org/wiki/Liskov_substitution_principle">Liskov |
| * Substitution Principle</a>. This method should not be used. |
| * |
| * @return 0 if no further bytes are available. Otherwise returns 1, |
| * which suggests (but does not guarantee) that additional bytes are |
| * available. |
| * @throws IOException if this stream is closed or an error occurs |
| */ |
| @Override |
| public int available() throws IOException { |
| checkClosed(); |
| return available ? 1 : 0; |
| } |
| |
| /** |
| * Returns false because {@code DeflaterInputStream} does not support |
| * {@code mark}/{@code reset}. |
| */ |
| @Override |
| public boolean markSupported() { |
| return false; |
| } |
| |
| /** |
| * This operation is not supported and does nothing. |
| */ |
| @Override |
| public void mark(int limit) { |
| } |
| |
| /** |
| * This operation is not supported and throws {@code IOException}. |
| */ |
| @Override |
| public void reset() throws IOException { |
| throw new IOException(); |
| } |
| |
| private void checkClosed() throws IOException { |
| if (closed) { |
| throw new IOException("Stream is closed"); |
| } |
| } |
| } |