| /* ZipInputStream.java -- |
| Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.util.zip; |
| |
| import java.io.EOFException; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.UnsupportedEncodingException; |
| |
| /** |
| * This is a FilterInputStream that reads the files in an zip archive |
| * one after another. It has a special method to get the zip entry of |
| * the next file. The zip entry contains information about the file name |
| * size, compressed size, CRC, etc. |
| * |
| * It includes support for STORED and DEFLATED entries. |
| * |
| * @author Jochen Hoenicke |
| */ |
| public class ZipInputStream extends InflaterInputStream implements ZipConstants |
| { |
| private CRC32 crc = new CRC32(); |
| private ZipEntry entry = null; |
| |
| private int csize; |
| private int size; |
| private int method; |
| private int flags; |
| private int avail; |
| private boolean entryAtEOF; |
| |
| /** |
| * Creates a new Zip input stream, reading a zip archive. |
| */ |
| public ZipInputStream(InputStream in) |
| { |
| super(in, new Inflater(true)); |
| } |
| |
| private void fillBuf() throws IOException |
| { |
| avail = len = in.read(buf, 0, buf.length); |
| } |
| |
| private int readBuf(byte[] out, int offset, int length) throws IOException |
| { |
| if (avail <= 0) |
| { |
| fillBuf(); |
| if (avail <= 0) |
| return -1; |
| } |
| if (length > avail) |
| length = avail; |
| System.arraycopy(buf, len - avail, out, offset, length); |
| avail -= length; |
| return length; |
| } |
| |
| private void readFully(byte[] out) throws IOException |
| { |
| int off = 0; |
| int len = out.length; |
| while (len > 0) |
| { |
| int count = readBuf(out, off, len); |
| if (count == -1) |
| throw new EOFException(); |
| off += count; |
| len -= count; |
| } |
| } |
| |
| private int readLeByte() throws IOException |
| { |
| if (avail <= 0) |
| { |
| fillBuf(); |
| if (avail <= 0) |
| throw new ZipException("EOF in header"); |
| } |
| return buf[len - avail--] & 0xff; |
| } |
| |
| /** |
| * Read an unsigned short in little endian byte order. |
| */ |
| private int readLeShort() throws IOException |
| { |
| return readLeByte() | (readLeByte() << 8); |
| } |
| |
| /** |
| * Read an int in little endian byte order. |
| */ |
| private int readLeInt() throws IOException |
| { |
| return readLeShort() | (readLeShort() << 16); |
| } |
| |
| /** |
| * Open the next entry from the zip archive, and return its description. |
| * If the previous entry wasn't closed, this method will close it. |
| */ |
| public ZipEntry getNextEntry() throws IOException |
| { |
| if (crc == null) |
| throw new IOException("Stream closed."); |
| if (entry != null) |
| closeEntry(); |
| |
| int header = readLeInt(); |
| if (header == CENSIG) |
| { |
| /* Central Header reached. */ |
| close(); |
| return null; |
| } |
| if (header != LOCSIG) |
| throw new ZipException("Wrong Local header signature: " |
| + Integer.toHexString(header)); |
| /* skip version */ |
| readLeShort(); |
| flags = readLeShort(); |
| method = readLeShort(); |
| int dostime = readLeInt(); |
| int crc = readLeInt(); |
| csize = readLeInt(); |
| size = readLeInt(); |
| int nameLen = readLeShort(); |
| int extraLen = readLeShort(); |
| |
| if (method == ZipOutputStream.STORED && csize != size) |
| throw new ZipException("Stored, but compressed != uncompressed"); |
| |
| |
| byte[] buffer = new byte[nameLen]; |
| readFully(buffer); |
| String name; |
| try |
| { |
| name = new String(buffer, "UTF-8"); |
| } |
| catch (UnsupportedEncodingException uee) |
| { |
| throw new AssertionError(uee); |
| } |
| |
| entry = createZipEntry(name); |
| entryAtEOF = false; |
| entry.setMethod(method); |
| if ((flags & 8) == 0) |
| { |
| entry.setCrc(crc & 0xffffffffL); |
| entry.setSize(size & 0xffffffffL); |
| entry.setCompressedSize(csize & 0xffffffffL); |
| } |
| entry.setDOSTime(dostime); |
| if (extraLen > 0) |
| { |
| byte[] extra = new byte[extraLen]; |
| readFully(extra); |
| entry.setExtra(extra); |
| } |
| |
| if (method == ZipOutputStream.DEFLATED && avail > 0) |
| { |
| System.arraycopy(buf, len - avail, buf, 0, avail); |
| len = avail; |
| avail = 0; |
| inf.setInput(buf, 0, len); |
| } |
| return entry; |
| } |
| |
| private void readDataDescr() throws IOException |
| { |
| if (readLeInt() != EXTSIG) |
| throw new ZipException("Data descriptor signature not found"); |
| entry.setCrc(readLeInt() & 0xffffffffL); |
| csize = readLeInt(); |
| size = readLeInt(); |
| entry.setSize(size & 0xffffffffL); |
| entry.setCompressedSize(csize & 0xffffffffL); |
| } |
| |
| /** |
| * Closes the current zip entry and moves to the next one. |
| */ |
| public void closeEntry() throws IOException |
| { |
| if (crc == null) |
| throw new IOException("Stream closed."); |
| if (entry == null) |
| return; |
| |
| if (method == ZipOutputStream.DEFLATED) |
| { |
| if ((flags & 8) != 0) |
| { |
| /* We don't know how much we must skip, read until end. */ |
| byte[] tmp = new byte[2048]; |
| while (read(tmp) > 0) |
| ; |
| /* read will close this entry */ |
| return; |
| } |
| csize -= inf.getTotalIn(); |
| avail = inf.getRemaining(); |
| } |
| |
| if (avail > csize && csize >= 0) |
| avail -= csize; |
| else |
| { |
| csize -= avail; |
| avail = 0; |
| while (csize != 0) |
| { |
| long skipped = in.skip(csize & 0xffffffffL); |
| if (skipped <= 0) |
| throw new ZipException("zip archive ends early."); |
| csize -= skipped; |
| } |
| } |
| |
| size = 0; |
| crc.reset(); |
| if (method == ZipOutputStream.DEFLATED) |
| inf.reset(); |
| entry = null; |
| entryAtEOF = true; |
| } |
| |
| public int available() throws IOException |
| { |
| return entryAtEOF ? 0 : 1; |
| } |
| |
| /** |
| * Reads a byte from the current zip entry. |
| * @return the byte or -1 on EOF. |
| * @exception IOException if a i/o error occured. |
| * @exception ZipException if the deflated stream is corrupted. |
| */ |
| public int read() throws IOException |
| { |
| byte[] b = new byte[1]; |
| if (read(b, 0, 1) <= 0) |
| return -1; |
| return b[0] & 0xff; |
| } |
| |
| /** |
| * Reads a block of bytes from the current zip entry. |
| * @return the number of bytes read (may be smaller, even before |
| * EOF), or -1 on EOF. |
| * @exception IOException if a i/o error occured. |
| * @exception ZipException if the deflated stream is corrupted. |
| */ |
| public int read(byte[] b, int off, int len) throws IOException |
| { |
| if (len == 0) |
| return 0; |
| if (crc == null) |
| throw new IOException("Stream closed."); |
| if (entry == null) |
| return -1; |
| boolean finished = false; |
| switch (method) |
| { |
| case ZipOutputStream.DEFLATED: |
| len = super.read(b, off, len); |
| if (len < 0) |
| { |
| if (!inf.finished()) |
| throw new ZipException("Inflater not finished!?"); |
| avail = inf.getRemaining(); |
| if ((flags & 8) != 0) |
| readDataDescr(); |
| |
| if (inf.getTotalIn() != csize |
| || inf.getTotalOut() != size) |
| throw new ZipException("size mismatch: "+csize+";"+size+" <-> "+inf.getTotalIn()+";"+inf.getTotalOut()); |
| inf.reset(); |
| finished = true; |
| } |
| break; |
| |
| case ZipOutputStream.STORED: |
| |
| if (len > csize && csize >= 0) |
| len = csize; |
| |
| len = readBuf(b, off, len); |
| if (len > 0) |
| { |
| csize -= len; |
| size -= len; |
| } |
| |
| if (csize == 0) |
| finished = true; |
| else if (len < 0) |
| throw new ZipException("EOF in stored block"); |
| break; |
| } |
| |
| if (len > 0) |
| crc.update(b, off, len); |
| |
| if (finished) |
| { |
| if ((crc.getValue() & 0xffffffffL) != entry.getCrc()) |
| throw new ZipException("CRC mismatch"); |
| crc.reset(); |
| entry = null; |
| entryAtEOF = true; |
| } |
| return len; |
| } |
| |
| /** |
| * Closes the zip file. |
| * @exception IOException if a i/o error occured. |
| */ |
| public void close() throws IOException |
| { |
| super.close(); |
| crc = null; |
| entry = null; |
| entryAtEOF = true; |
| } |
| |
| /** |
| * Creates a new zip entry for the given name. This is equivalent |
| * to new ZipEntry(name). |
| * @param name the name of the zip entry. |
| */ |
| protected ZipEntry createZipEntry(String name) |
| { |
| return new ZipEntry(name); |
| } |
| } |