/* * 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.IOException; import java.io.InputStream; import java.io.PushbackInputStream; import java.nio.ByteOrder; import java.nio.charset.ModifiedUtf8; import java.util.jar.Attributes; import java.util.jar.JarEntry; import java.util.Arrays; import libcore.io.Memory; import libcore.io.Streams; /** * Used to read (decompress) the data from zip files. * *
A zip file (or "archive") is a collection of (possibly) compressed files. * When reading from a {@code ZipInputStream}, you call {@link #getNextEntry} * which returns a {@link ZipEntry} of metadata corresponding to the userdata that follows. * When you appear to have hit the end of this stream (which is really just the end of the current * entry's userdata), call {@code getNextEntry} again. When it returns null, * there are no more entries in the input file. * *
Although {@code InflaterInputStream} can only read compressed zip * entries, this class can read non-compressed entries as well. * *
Use {@link ZipFile} if you need random access to entries by name, but use this class * if you just want to iterate over all entries. * *
Using {@code ZipInputStream} is a little more complicated than {@link GZIPInputStream} * because zip files are containers that can contain multiple files. This code pulls all the * files out of a zip file, similar to the {@code unzip(1)} utility. *
* InputStream is = ... * ZipInputStream zis = new ZipInputStream(new BufferedInputStream(is)); * try { * ZipEntry ze; * while ((ze = zis.getNextEntry()) != null) { * ByteArrayOutputStream baos = new ByteArrayOutputStream(); * byte[] buffer = new byte[1024]; * int count; * while ((count = zis.read(buffer)) != -1) { * baos.write(buffer, 0, count); * } * String filename = ze.getName(); * byte[] bytes = baos.toByteArray(); * // do something with 'filename' and 'bytes'... * } * } finally { * zis.close(); * } **/ public class ZipInputStream extends InflaterInputStream implements ZipConstants { private static final int ZIPLocalHeaderVersionNeeded = 20; private boolean entriesEnd = false; private boolean hasDD = false; private int entryIn = 0; private int inRead, lastRead = 0; private ZipEntry currentEntry; private final byte[] hdrBuf = new byte[LOCHDR - LOCVER]; private final CRC32 crc = new CRC32(); private byte[] nameBuf = new byte[256]; private char[] charBuf = new char[256]; /** * Constructs a new {@code ZipInputStream} to read zip entries from the given input stream. */ public ZipInputStream(InputStream stream) { super(new PushbackInputStream(stream, BUF_SIZE), new Inflater(true)); if (stream == null) { throw new NullPointerException("stream == null"); } } /** * Closes this {@code ZipInputStream}. * * @throws IOException * if an {@code IOException} occurs. */ @Override public void close() throws IOException { if (!closed) { closeEntry(); // Close the current entry super.close(); } } /** * Closes the current zip entry and prepares to read the next entry. * * @throws IOException * if an {@code IOException} occurs. */ public void closeEntry() throws IOException { checkClosed(); if (currentEntry == null) { return; } if (currentEntry instanceof java.util.jar.JarEntry) { Attributes temp = ((JarEntry) currentEntry).getAttributes(); if (temp != null && temp.containsKey("hidden")) { return; } } /* * The following code is careful to leave the ZipInputStream in a * consistent state, even when close() results in an exception. It does * so by: * - pushing bytes back into the source stream * - reading a data descriptor footer from the source stream * - resetting fields that manage the entry being closed */ // Ensure all entry bytes are read Exception failure = null; try { Streams.skipAll(this); } catch (Exception e) { failure = e; } int inB, out; if (currentEntry.compressionMethod == ZipEntry.DEFLATED) { inB = inf.getTotalIn(); out = inf.getTotalOut(); } else { inB = inRead; out = inRead; } int diff = entryIn - inB; // Pushback any required bytes if (diff != 0) { ((PushbackInputStream) in).unread(buf, len - diff, diff); } try { readAndVerifyDataDescriptor(inB, out); } catch (Exception e) { if (failure == null) { // otherwise we're already going to throw failure = e; } } inf.reset(); lastRead = inRead = entryIn = len = 0; crc.reset(); currentEntry = null; if (failure != null) { if (failure instanceof IOException) { throw (IOException) failure; } else if (failure instanceof RuntimeException) { throw (RuntimeException) failure; } AssertionError error = new AssertionError(); error.initCause(failure); throw error; } } private void readAndVerifyDataDescriptor(int inB, int out) throws IOException { if (hasDD) { Streams.readFully(in, hdrBuf, 0, EXTHDR); int sig = Memory.peekInt(hdrBuf, 0, ByteOrder.LITTLE_ENDIAN); if (sig != (int) EXTSIG) { throw new ZipException(String.format("unknown format (EXTSIG=%x)", sig)); } currentEntry.crc = ((long) Memory.peekInt(hdrBuf, EXTCRC, ByteOrder.LITTLE_ENDIAN)) & 0xffffffffL; currentEntry.compressedSize = ((long) Memory.peekInt(hdrBuf, EXTSIZ, ByteOrder.LITTLE_ENDIAN)) & 0xffffffffL; currentEntry.size = ((long) Memory.peekInt(hdrBuf, EXTLEN, ByteOrder.LITTLE_ENDIAN)) & 0xffffffffL; } if (currentEntry.crc != crc.getValue()) { throw new ZipException("CRC mismatch"); } if (currentEntry.compressedSize != inB || currentEntry.size != out) { throw new ZipException("Size mismatch"); } } /** * Returns the next entry from this {@code ZipInputStream} or {@code null} if * no more entries are present. * * @throws IOException if an {@code IOException} occurs. */ public ZipEntry getNextEntry() throws IOException { closeEntry(); if (entriesEnd) { return null; } // Read the signature to see whether there's another local file header. Streams.readFully(in, hdrBuf, 0, 4); int hdr = Memory.peekInt(hdrBuf, 0, ByteOrder.LITTLE_ENDIAN); if (hdr == CENSIG) { entriesEnd = true; return null; } if (hdr != LOCSIG) { return null; } // Read the local file header. Streams.readFully(in, hdrBuf, 0, (LOCHDR - LOCVER)); int version = peekShort(0) & 0xff; if (version > ZIPLocalHeaderVersionNeeded) { throw new ZipException("Cannot read local header version " + version); } int flags = peekShort(LOCFLG - LOCVER); if ((flags & ZipFile.GPBF_UNSUPPORTED_MASK) != 0) { throw new ZipException("Invalid General Purpose Bit Flag: " + flags); } hasDD = ((flags & ZipFile.GPBF_DATA_DESCRIPTOR_FLAG) != 0); int ceLastModifiedTime = peekShort(LOCTIM - LOCVER); int ceLastModifiedDate = peekShort(LOCTIM - LOCVER + 2); int ceCompressionMethod = peekShort(LOCHOW - LOCVER); long ceCrc = 0, ceCompressedSize = 0, ceSize = -1; if (!hasDD) { ceCrc = ((long) Memory.peekInt(hdrBuf, LOCCRC - LOCVER, ByteOrder.LITTLE_ENDIAN)) & 0xffffffffL; ceCompressedSize = ((long) Memory.peekInt(hdrBuf, LOCSIZ - LOCVER, ByteOrder.LITTLE_ENDIAN)) & 0xffffffffL; ceSize = ((long) Memory.peekInt(hdrBuf, LOCLEN - LOCVER, ByteOrder.LITTLE_ENDIAN)) & 0xffffffffL; } int nameLength = peekShort(LOCNAM - LOCVER); if (nameLength == 0) { throw new ZipException("Entry is not named"); } int extraLength = peekShort(LOCEXT - LOCVER); if (nameLength > nameBuf.length) { nameBuf = new byte[nameLength]; // The bytes are modified UTF-8, so the number of chars will always be less than or // equal to the number of bytes. It's fine if this buffer is too long. charBuf = new char[nameLength]; } Streams.readFully(in, nameBuf, 0, nameLength); currentEntry = createZipEntry(ModifiedUtf8.decode(nameBuf, charBuf, 0, nameLength)); currentEntry.time = ceLastModifiedTime; currentEntry.modDate = ceLastModifiedDate; currentEntry.setMethod(ceCompressionMethod); if (ceSize != -1) { currentEntry.setCrc(ceCrc); currentEntry.setSize(ceSize); currentEntry.setCompressedSize(ceCompressedSize); } if (extraLength > 0) { byte[] extraData = new byte[extraLength]; Streams.readFully(in, extraData, 0, extraLength); currentEntry.setExtra(extraData); } return currentEntry; } private int peekShort(int offset) { return Memory.peekShort(hdrBuf, offset, ByteOrder.LITTLE_ENDIAN) & 0xffff; } /** * Reads up to the specified number of uncompressed bytes into the buffer * starting at the offset. * * @return the number of bytes read */ @Override public int read(byte[] buffer, int offset, int byteCount) throws IOException { checkClosed(); Arrays.checkOffsetAndCount(buffer.length, offset, byteCount); if (inf.finished() || currentEntry == null) { return -1; } if (currentEntry.compressionMethod == ZipEntry.STORED) { int csize = (int) currentEntry.size; if (inRead >= csize) { return -1; } if (lastRead >= len) { lastRead = 0; if ((len = in.read(buf)) == -1) { eof = true; return -1; } entryIn += len; } int toRead = byteCount > (len - lastRead) ? len - lastRead : byteCount; if ((csize - inRead) < toRead) { toRead = csize - inRead; } System.arraycopy(buf, lastRead, buffer, offset, toRead); lastRead += toRead; inRead += toRead; crc.update(buffer, offset, toRead); return toRead; } if (inf.needsInput()) { fill(); if (len > 0) { entryIn += len; } } int read; try { read = inf.inflate(buffer, offset, byteCount); } catch (DataFormatException e) { throw new ZipException(e.getMessage()); } if (read == 0 && inf.finished()) { return -1; } crc.update(buffer, offset, read); return read; } @Override public int available() throws IOException { checkClosed(); // The InflaterInputStream contract says we must only return 0 or 1. return (currentEntry == null || inRead < currentEntry.size) ? 1 : 0; } /** * creates a {@link ZipEntry } with the given name. * * @param name * the name of the entry. * @return the created {@code ZipEntry}. */ protected ZipEntry createZipEntry(String name) { return new ZipEntry(name); } private void checkClosed() throws IOException { if (closed) { throw new IOException("Stream is closed"); } } }