| /* |
| * Copyright (c) 1996, 2006, 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.FilterInputStream; |
| import java.io.InputStream; |
| import java.io.IOException; |
| import java.io.EOFException; |
| |
| /** |
| * This class implements a stream filter for uncompressing data in the |
| * "deflate" compression format. It is also used as the basis for other |
| * decompression filters, such as GZIPInputStream. |
| * |
| * @see Inflater |
| * @author David Connelly |
| */ |
| public |
| class InflaterInputStream extends FilterInputStream { |
| /** |
| * Decompressor for this stream. |
| */ |
| protected Inflater inf; |
| |
| /** |
| * Input buffer for decompression. |
| */ |
| protected byte[] buf; |
| |
| /** |
| * Length of input buffer. |
| */ |
| protected int len; |
| |
| private boolean closed = false; |
| // this flag is set to true after EOF has reached |
| private boolean reachEOF = false; |
| |
| /** |
| * Check to make sure that this stream has not been closed |
| */ |
| private void ensureOpen() throws IOException { |
| if (closed) { |
| throw new IOException("Stream closed"); |
| } |
| } |
| |
| |
| /** |
| * Creates a new input stream with the specified decompressor and |
| * buffer size. |
| * @param in the input stream |
| * @param inf the decompressor ("inflater") |
| * @param size the input buffer size |
| * @exception IllegalArgumentException if size is <= 0 |
| */ |
| public InflaterInputStream(InputStream in, Inflater inf, int size) { |
| super(in); |
| if (in == null || inf == null) { |
| throw new NullPointerException(); |
| } else if (size <= 0) { |
| throw new IllegalArgumentException("buffer size <= 0"); |
| } |
| this.inf = inf; |
| buf = new byte[size]; |
| } |
| |
| /** |
| * Creates a new input stream with the specified decompressor and a |
| * default buffer size. |
| * @param in the input stream |
| * @param inf the decompressor ("inflater") |
| */ |
| public InflaterInputStream(InputStream in, Inflater inf) { |
| this(in, inf, 512); |
| } |
| |
| boolean usesDefaultInflater = false; |
| |
| /** |
| * Creates a new input stream with a default decompressor and buffer size. |
| * @param in the input stream |
| */ |
| public InflaterInputStream(InputStream in) { |
| this(in, new Inflater()); |
| usesDefaultInflater = true; |
| } |
| |
| private byte[] singleByteBuf = new byte[1]; |
| |
| /** |
| * Reads a byte of uncompressed data. This method will block until |
| * enough input is available for decompression. |
| * @return the byte read, or -1 if end of compressed input is reached |
| * @exception IOException if an I/O error has occurred |
| */ |
| public int read() throws IOException { |
| ensureOpen(); |
| return read(singleByteBuf, 0, 1) == -1 ? -1 : singleByteBuf[0] & 0xff; |
| } |
| |
| /** |
| * Reads uncompressed data into an array of bytes. If <code>len</code> is not |
| * zero, the method will block until some input can be decompressed; otherwise, |
| * no bytes are read and <code>0</code> is returned. |
| * @param b the buffer into which the data is read |
| * @param off the start offset in the destination array <code>b</code> |
| * @param len the maximum number of bytes read |
| * @return the actual number of bytes read, or -1 if the end of the |
| * compressed input is reached or a preset dictionary is needed |
| * @exception NullPointerException If <code>b</code> is <code>null</code>. |
| * @exception IndexOutOfBoundsException If <code>off</code> is negative, |
| * <code>len</code> is negative, or <code>len</code> is greater than |
| * <code>b.length - off</code> |
| * @exception ZipException if a ZIP format error has occurred |
| * @exception IOException if an I/O error has occurred |
| */ |
| public int read(byte[] b, int off, int len) throws IOException { |
| ensureOpen(); |
| if (b == null) { |
| throw new NullPointerException(); |
| } else if (off < 0 || len < 0 || len > b.length - off) { |
| throw new IndexOutOfBoundsException(); |
| } else if (len == 0) { |
| return 0; |
| } |
| try { |
| int n; |
| while ((n = inf.inflate(b, off, len)) == 0) { |
| if (inf.finished() || inf.needsDictionary()) { |
| reachEOF = true; |
| return -1; |
| } |
| if (inf.needsInput()) { |
| fill(); |
| } |
| } |
| return n; |
| } catch (DataFormatException e) { |
| String s = e.getMessage(); |
| throw new ZipException(s != null ? s : "Invalid ZLIB data format"); |
| } |
| } |
| |
| /** |
| * Returns 0 after EOF has been reached, otherwise always return 1. |
| * <p> |
| * Programs should not count on this method to return the actual number |
| * of bytes that could be read without blocking. |
| * |
| * @return 1 before EOF and 0 after EOF. |
| * @exception IOException if an I/O error occurs. |
| * |
| */ |
| public int available() throws IOException { |
| ensureOpen(); |
| if (reachEOF) { |
| return 0; |
| } else { |
| return 1; |
| } |
| } |
| |
| private byte[] b = new byte[512]; |
| |
| /** |
| * Skips specified number of bytes of uncompressed data. |
| * @param n the number of bytes to skip |
| * @return the actual number of bytes skipped. |
| * @exception IOException if an I/O error has occurred |
| * @exception IllegalArgumentException if n < 0 |
| */ |
| public long skip(long n) throws IOException { |
| if (n < 0) { |
| throw new IllegalArgumentException("negative skip length"); |
| } |
| ensureOpen(); |
| int max = (int)Math.min(n, Integer.MAX_VALUE); |
| int total = 0; |
| while (total < max) { |
| int len = max - total; |
| if (len > b.length) { |
| len = b.length; |
| } |
| len = read(b, 0, len); |
| if (len == -1) { |
| reachEOF = true; |
| break; |
| } |
| total += len; |
| } |
| return total; |
| } |
| |
| /** |
| * Closes this input stream and releases any system resources associated |
| * with the stream. |
| * @exception IOException if an I/O error has occurred |
| */ |
| public void close() throws IOException { |
| if (!closed) { |
| if (usesDefaultInflater) |
| inf.end(); |
| in.close(); |
| closed = true; |
| } |
| } |
| |
| /** |
| * Fills input buffer with more data to decompress. |
| * @exception IOException if an I/O error has occurred |
| */ |
| protected void fill() throws IOException { |
| ensureOpen(); |
| len = in.read(buf, 0, buf.length); |
| if (len == -1) { |
| throw new EOFException("Unexpected end of ZLIB input stream"); |
| } |
| inf.setInput(buf, 0, len); |
| } |
| |
| /** |
| * Tests if this input stream supports the <code>mark</code> and |
| * <code>reset</code> methods. The <code>markSupported</code> |
| * method of <code>InflaterInputStream</code> returns |
| * <code>false</code>. |
| * |
| * @return a <code>boolean</code> indicating if this stream type supports |
| * the <code>mark</code> and <code>reset</code> methods. |
| * @see java.io.InputStream#mark(int) |
| * @see java.io.InputStream#reset() |
| */ |
| public boolean markSupported() { |
| return false; |
| } |
| |
| /** |
| * Marks the current position in this input stream. |
| * |
| * <p> The <code>mark</code> method of <code>InflaterInputStream</code> |
| * does nothing. |
| * |
| * @param readlimit the maximum limit of bytes that can be read before |
| * the mark position becomes invalid. |
| * @see java.io.InputStream#reset() |
| */ |
| public synchronized void mark(int readlimit) { |
| } |
| |
| /** |
| * Repositions this stream to the position at the time the |
| * <code>mark</code> method was last called on this input stream. |
| * |
| * <p> The method <code>reset</code> for class |
| * <code>InflaterInputStream</code> does nothing except throw an |
| * <code>IOException</code>. |
| * |
| * @exception IOException if this method is invoked. |
| * @see java.io.InputStream#mark(int) |
| * @see java.io.IOException |
| */ |
| public synchronized void reset() throws IOException { |
| throw new IOException("mark/reset not supported"); |
| } |
| } |