src/java.base/share/classes/java/util/zip/ZipInputStream.java
changeset 47216 71c04702a3d5
parent 45434 4582657c7260
child 50238 a9307f400f5a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/util/zip/ZipInputStream.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,426 @@
+/*
+ * Copyright (c) 1996, 2015, 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.InputStream;
+import java.io.IOException;
+import java.io.EOFException;
+import java.io.PushbackInputStream;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import static java.util.zip.ZipConstants64.*;
+import static java.util.zip.ZipUtils.*;
+
+/**
+ * This class implements an input stream filter for reading files in the
+ * ZIP file format. Includes support for both compressed and uncompressed
+ * entries.
+ *
+ * @author      David Connelly
+ * @since 1.1
+ */
+public
+class ZipInputStream extends InflaterInputStream implements ZipConstants {
+    private ZipEntry entry;
+    private int flag;
+    private CRC32 crc = new CRC32();
+    private long remaining;
+    private byte[] tmpbuf = new byte[512];
+
+    private static final int STORED = ZipEntry.STORED;
+    private static final int DEFLATED = ZipEntry.DEFLATED;
+
+    private boolean closed = false;
+    // this flag is set to true after EOF has reached for
+    // one entry
+    private boolean entryEOF = false;
+
+    private ZipCoder zc;
+
+    /**
+     * 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 ZIP input stream.
+     *
+     * <p>The UTF-8 {@link java.nio.charset.Charset charset} is used to
+     * decode the entry names.
+     *
+     * @param in the actual input stream
+     */
+    public ZipInputStream(InputStream in) {
+        this(in, StandardCharsets.UTF_8);
+    }
+
+    /**
+     * Creates a new ZIP input stream.
+     *
+     * @param in the actual input stream
+     *
+     * @param charset
+     *        The {@linkplain java.nio.charset.Charset charset} to be
+     *        used to decode the ZIP entry name (ignored if the
+     *        <a href="package-summary.html#lang_encoding"> language
+     *        encoding bit</a> of the ZIP entry's general purpose bit
+     *        flag is set).
+     *
+     * @since 1.7
+     */
+    public ZipInputStream(InputStream in, Charset charset) {
+        super(new PushbackInputStream(in, 512), new Inflater(true), 512);
+        usesDefaultInflater = true;
+        if(in == null) {
+            throw new NullPointerException("in is null");
+        }
+        if (charset == null)
+            throw new NullPointerException("charset is null");
+        this.zc = ZipCoder.get(charset);
+    }
+
+    /**
+     * Reads the next ZIP file entry and positions the stream at the
+     * beginning of the entry data.
+     * @return the next ZIP file entry, or null if there are no more entries
+     * @exception ZipException if a ZIP file error has occurred
+     * @exception IOException if an I/O error has occurred
+     */
+    public ZipEntry getNextEntry() throws IOException {
+        ensureOpen();
+        if (entry != null) {
+            closeEntry();
+        }
+        crc.reset();
+        inf.reset();
+        if ((entry = readLOC()) == null) {
+            return null;
+        }
+        if (entry.method == STORED) {
+            remaining = entry.size;
+        }
+        entryEOF = false;
+        return entry;
+    }
+
+    /**
+     * Closes the current ZIP entry and positions the stream for reading the
+     * next entry.
+     * @exception ZipException if a ZIP file error has occurred
+     * @exception IOException if an I/O error has occurred
+     */
+    public void closeEntry() throws IOException {
+        ensureOpen();
+        while (read(tmpbuf, 0, tmpbuf.length) != -1) ;
+        entryEOF = true;
+    }
+
+    /**
+     * Returns 0 after EOF has reached for the current entry data,
+     * 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 has reached for current entry.
+     * @exception  IOException  if an I/O error occurs.
+     *
+     */
+    public int available() throws IOException {
+        ensureOpen();
+        if (entryEOF) {
+            return 0;
+        } else {
+            return 1;
+        }
+    }
+
+    /**
+     * Reads from the current ZIP entry into an array of bytes.
+     * If <code>len</code> is not zero, the method
+     * blocks until some input is available; 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
+     *         entry is reached
+     * @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 file 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 (off < 0 || len < 0 || off > b.length - len) {
+            throw new IndexOutOfBoundsException();
+        } else if (len == 0) {
+            return 0;
+        }
+
+        if (entry == null) {
+            return -1;
+        }
+        switch (entry.method) {
+        case DEFLATED:
+            len = super.read(b, off, len);
+            if (len == -1) {
+                readEnd(entry);
+                entryEOF = true;
+                entry = null;
+            } else {
+                crc.update(b, off, len);
+            }
+            return len;
+        case STORED:
+            if (remaining <= 0) {
+                entryEOF = true;
+                entry = null;
+                return -1;
+            }
+            if (len > remaining) {
+                len = (int)remaining;
+            }
+            len = in.read(b, off, len);
+            if (len == -1) {
+                throw new ZipException("unexpected EOF");
+            }
+            crc.update(b, off, len);
+            remaining -= len;
+            if (remaining == 0 && entry.crc != crc.getValue()) {
+                throw new ZipException(
+                    "invalid entry CRC (expected 0x" + Long.toHexString(entry.crc) +
+                    " but got 0x" + Long.toHexString(crc.getValue()) + ")");
+            }
+            return len;
+        default:
+            throw new ZipException("invalid compression method");
+        }
+    }
+
+    /**
+     * Skips specified number of bytes in the current ZIP entry.
+     * @param n the number of bytes to skip
+     * @return the actual number of bytes skipped
+     * @exception ZipException if a ZIP file error has occurred
+     * @exception IOException if an I/O error has occurred
+     * @exception IllegalArgumentException if {@code 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 > tmpbuf.length) {
+                len = tmpbuf.length;
+            }
+            len = read(tmpbuf, 0, len);
+            if (len == -1) {
+                entryEOF = 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) {
+            super.close();
+            closed = true;
+        }
+    }
+
+    private byte[] b = new byte[256];
+
+    /*
+     * Reads local file (LOC) header for next entry.
+     */
+    private ZipEntry readLOC() throws IOException {
+        try {
+            readFully(tmpbuf, 0, LOCHDR);
+        } catch (EOFException e) {
+            return null;
+        }
+        if (get32(tmpbuf, 0) != LOCSIG) {
+            return null;
+        }
+        // get flag first, we need check EFS.
+        flag = get16(tmpbuf, LOCFLG);
+        // get the entry name and create the ZipEntry first
+        int len = get16(tmpbuf, LOCNAM);
+        int blen = b.length;
+        if (len > blen) {
+            do {
+                blen = blen * 2;
+            } while (len > blen);
+            b = new byte[blen];
+        }
+        readFully(b, 0, len);
+        // Force to use UTF-8 if the EFS bit is ON, even the cs is NOT UTF-8
+        ZipEntry e = createZipEntry(((flag & EFS) != 0)
+                                    ? zc.toStringUTF8(b, len)
+                                    : zc.toString(b, len));
+        // now get the remaining fields for the entry
+        if ((flag & 1) == 1) {
+            throw new ZipException("encrypted ZIP entry not supported");
+        }
+        e.method = get16(tmpbuf, LOCHOW);
+        e.xdostime = get32(tmpbuf, LOCTIM);
+        if ((flag & 8) == 8) {
+            /* "Data Descriptor" present */
+            if (e.method != DEFLATED) {
+                throw new ZipException(
+                        "only DEFLATED entries can have EXT descriptor");
+            }
+        } else {
+            e.crc = get32(tmpbuf, LOCCRC);
+            e.csize = get32(tmpbuf, LOCSIZ);
+            e.size = get32(tmpbuf, LOCLEN);
+        }
+        len = get16(tmpbuf, LOCEXT);
+        if (len > 0) {
+            byte[] extra = new byte[len];
+            readFully(extra, 0, len);
+            e.setExtra0(extra,
+                        e.csize == ZIP64_MAGICVAL || e.size == ZIP64_MAGICVAL);
+        }
+        return e;
+    }
+
+    /**
+     * Creates a new <code>ZipEntry</code> object for the specified
+     * entry name.
+     *
+     * @param name the ZIP file entry name
+     * @return the ZipEntry just created
+     */
+    protected ZipEntry createZipEntry(String name) {
+        return new ZipEntry(name);
+    }
+
+    /**
+     * Reads end of deflated entry as well as EXT descriptor if present.
+     *
+     * Local headers for DEFLATED entries may optionally be followed by a
+     * data descriptor, and that data descriptor may optionally contain a
+     * leading signature (EXTSIG).
+     *
+     * From the zip spec http://www.pkware.com/documents/casestudies/APPNOTE.TXT
+     *
+     * """Although not originally assigned a signature, the value 0x08074b50
+     * has commonly been adopted as a signature value for the data descriptor
+     * record.  Implementers should be aware that ZIP files may be
+     * encountered with or without this signature marking data descriptors
+     * and should account for either case when reading ZIP files to ensure
+     * compatibility."""
+     */
+    private void readEnd(ZipEntry e) throws IOException {
+        int n = inf.getRemaining();
+        if (n > 0) {
+            ((PushbackInputStream)in).unread(buf, len - n, n);
+        }
+        if ((flag & 8) == 8) {
+            /* "Data Descriptor" present */
+            if (inf.getBytesWritten() > ZIP64_MAGICVAL ||
+                inf.getBytesRead() > ZIP64_MAGICVAL) {
+                // ZIP64 format
+                readFully(tmpbuf, 0, ZIP64_EXTHDR);
+                long sig = get32(tmpbuf, 0);
+                if (sig != EXTSIG) { // no EXTSIG present
+                    e.crc = sig;
+                    e.csize = get64(tmpbuf, ZIP64_EXTSIZ - ZIP64_EXTCRC);
+                    e.size = get64(tmpbuf, ZIP64_EXTLEN - ZIP64_EXTCRC);
+                    ((PushbackInputStream)in).unread(
+                        tmpbuf, ZIP64_EXTHDR - ZIP64_EXTCRC, ZIP64_EXTCRC);
+                } else {
+                    e.crc = get32(tmpbuf, ZIP64_EXTCRC);
+                    e.csize = get64(tmpbuf, ZIP64_EXTSIZ);
+                    e.size = get64(tmpbuf, ZIP64_EXTLEN);
+                }
+            } else {
+                readFully(tmpbuf, 0, EXTHDR);
+                long sig = get32(tmpbuf, 0);
+                if (sig != EXTSIG) { // no EXTSIG present
+                    e.crc = sig;
+                    e.csize = get32(tmpbuf, EXTSIZ - EXTCRC);
+                    e.size = get32(tmpbuf, EXTLEN - EXTCRC);
+                    ((PushbackInputStream)in).unread(
+                                               tmpbuf, EXTHDR - EXTCRC, EXTCRC);
+                } else {
+                    e.crc = get32(tmpbuf, EXTCRC);
+                    e.csize = get32(tmpbuf, EXTSIZ);
+                    e.size = get32(tmpbuf, EXTLEN);
+                }
+            }
+        }
+        if (e.size != inf.getBytesWritten()) {
+            throw new ZipException(
+                "invalid entry size (expected " + e.size +
+                " but got " + inf.getBytesWritten() + " bytes)");
+        }
+        if (e.csize != inf.getBytesRead()) {
+            throw new ZipException(
+                "invalid entry compressed size (expected " + e.csize +
+                " but got " + inf.getBytesRead() + " bytes)");
+        }
+        if (e.crc != crc.getValue()) {
+            throw new ZipException(
+                "invalid entry CRC (expected 0x" + Long.toHexString(e.crc) +
+                " but got 0x" + Long.toHexString(crc.getValue()) + ")");
+        }
+    }
+
+    /*
+     * Reads bytes, blocking until all bytes are read.
+     */
+    private void readFully(byte[] b, int off, int len) throws IOException {
+        while (len > 0) {
+            int n = in.read(b, off, len);
+            if (n == -1) {
+                throw new EOFException();
+            }
+            off += n;
+            len -= n;
+        }
+    }
+
+}