    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 *   https://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019package org.apache.commons.compress.archivers.tar;
    020
    021import static java.nio.charset.StandardCharsets.UTF_8;
    022
    023import java.io.File;
    024import java.io.IOException;
    025import java.io.OutputStream;
    026import java.io.StringWriter;
    027import java.math.BigDecimal;
    028import java.math.RoundingMode;
    029import java.nio.ByteBuffer;
    030import java.nio.charset.StandardCharsets;
    031import java.nio.file.LinkOption;
    032import java.nio.file.Path;
    033import java.nio.file.attribute.FileTime;
    034import java.time.Instant;
    035import java.util.HashMap;
    036import java.util.Map;
    037
    038import org.apache.commons.compress.archivers.ArchiveOutputStream;
    039import org.apache.commons.compress.archivers.zip.ZipEncoding;
    040import org.apache.commons.compress.archivers.zip.ZipEncodingHelper;
    041import org.apache.commons.compress.utils.FixedLengthBlockOutputStream;
    042import org.apache.commons.io.Charsets;
    043import org.apache.commons.io.file.attribute.FileTimes;
    044import org.apache.commons.io.output.CountingOutputStream;
    045import org.apache.commons.lang3.ArrayFill;
    046
    047/**
    048 * The TarOutputStream writes a Unix tar archive as an OutputStream. Methods are provided to put entries, and then write their contents by writing to this
    049 * stream using write().
    050 *
    051 * <p>
    052 * tar archives consist of a sequence of records of 512 bytes each that are grouped into blocks. Prior to Apache Commons Compress 1.14 it has been possible to
    053 * configure a record size different from 512 bytes and arbitrary block sizes. Starting with Compress 1.15 512 is the only valid option for the record size and
    054 * the block size must be a multiple of 512. Also the default block size changed from 10240 bytes prior to Compress 1.15 to 512 bytes with Compress 1.15.
    055 * </p>
    056 *
    057 * @NotThreadSafe
    058 */
    059public class TarArchiveOutputStream extends ArchiveOutputStream<TarArchiveEntry> {
    060
    061    /**
    062     * Fail if a long file name is required in the archive.
    063     */
    064    public static final int LONGFILE_ERROR = 0;
    065
    066    /**
    067     * Long paths will be truncated in the archive.
    068     */
    069    public static final int LONGFILE_TRUNCATE = 1;
    070
    071    /**
    072     * GNU tar extensions are used to store long file names in the archive.
    073     */
    074    public static final int LONGFILE_GNU = 2;
    075
    076    /**
    077     * POSIX/PAX extensions are used to store long file names in the archive.
    078     */
    079    public static final int LONGFILE_POSIX = 3;
    080
    081    /**
    082     * Fail if a big number (for example size &gt; 8GiB) is required in the archive.
    083     */
    084    public static final int BIGNUMBER_ERROR = 0;
    085
    086    /**
    087     * star/GNU tar/BSD tar extensions are used to store big number in the archive.
    088     */
    089    public static final int BIGNUMBER_STAR = 1;
    090
    091    /**
    092     * POSIX/PAX extensions are used to store big numbers in the archive.
    093     */
    094    public static final int BIGNUMBER_POSIX = 2;
    095    private static final int RECORD_SIZE = 512;
    096
    097    private static final ZipEncoding ASCII = ZipEncodingHelper.getZipEncoding(StandardCharsets.US_ASCII);
    098
    099    private static final int BLOCK_SIZE_UNSPECIFIED = -511;
    100    private long currSize;
    101    private String currName;
    102    private long currBytes;
    103    private final byte[] recordBuf;
    104    private int longFileMode = LONGFILE_ERROR;
    105    private int bigNumberMode = BIGNUMBER_ERROR;
    106
    107    private long recordsWritten;
    108
    109    private final int recordsPerBlock;
    110
    111    /**
    112     * Indicates if putArchiveEntry has been called without closeArchiveEntry
    113     */
    114    private boolean haveUnclosedEntry;
    115
    116    private final CountingOutputStream countingOut;
    117
    118    private final ZipEncoding zipEncoding;
    119
    120    /**
    121     * The provided encoding (for unit tests).
    122     */
    123    final String charsetName;
    124
    125    private boolean addPaxHeadersForNonAsciiNames;
    126
    127    /**
    128     * Constructs a new instance.
    129     *
    130     * <p>
    131     * Uses a block size of 512 bytes.
    132     * </p>
    133     *
    134     * @param os the output stream to use
    135     */
    136    public TarArchiveOutputStream(final OutputStream os) {
    137        this(os, BLOCK_SIZE_UNSPECIFIED);
    138    }
    139
    140    /**
    141     * Constructs a new instance.
    142     *
    143     * @param os        the output stream to use
    144     * @param blockSize the block size to use. Must be a multiple of 512 bytes.
    145     */
    146    public TarArchiveOutputStream(final OutputStream os, final int blockSize) {
    147        this(os, blockSize, null);
    148    }
    149
    150    /**
    151     * Constructs a new instance.
    152     *
    153     * @param os         the output stream to use
    154     * @param blockSize  the block size to use
    155     * @param recordSize the record size to use. Must be 512 bytes.
    156     * @deprecated recordSize must always be 512 bytes. An IllegalArgumentException will be thrown if any other value is used
    157     */
    158    @Deprecated
    159    public TarArchiveOutputStream(final OutputStream os, final int blockSize, final int recordSize) {
    160        this(os, blockSize, recordSize, null);
    161    }
    162
    163    /**
    164     * Constructs a new instance.
    165     *
    166     * @param os         the output stream to use
    167     * @param blockSize  the block size to use . Must be a multiple of 512 bytes.
    168     * @param recordSize the record size to use. Must be 512 bytes.
    169     * @param encoding   name of the encoding to use for file names
    170     * @since 1.4
    171     * @deprecated recordSize must always be 512 bytes. An IllegalArgumentException will be thrown if any other value is used.
    172     */
    173    @Deprecated
    174    public TarArchiveOutputStream(final OutputStream os, final int blockSize, final int recordSize, final String encoding) {
    175        this(os, blockSize, encoding);
    176        if (recordSize != RECORD_SIZE) {
    177            throw new IllegalArgumentException("Tar record size must always be 512 bytes. Attempt to set size of " + recordSize);
    178        }
    179
    180    }
    181
    182    /**
    183     * Constructs a new instance.
    184     *
    185     * @param os        the output stream to use
    186     * @param blockSize the block size to use. Must be a multiple of 512 bytes.
    187     * @param charset  name of the encoding to use for file names
    188     * @since 1.4
    189     */
    190    public TarArchiveOutputStream(final OutputStream os, final int blockSize, final String charset) {
    191        super(os);
    192        final int realBlockSize;
    193        if (BLOCK_SIZE_UNSPECIFIED == blockSize) {
    194            realBlockSize = RECORD_SIZE;
    195        } else {
    196            realBlockSize = blockSize;
    197        }
    198
    199        if (realBlockSize <= 0 || realBlockSize % RECORD_SIZE != 0) {
    200            throw new IllegalArgumentException("Block size must be a multiple of 512 bytes. Attempt to use set size of " + blockSize);
    201        }
    202        this.out = new FixedLengthBlockOutputStream(countingOut = new CountingOutputStream(os), RECORD_SIZE);
    203        this.charsetName = Charsets.toCharset(charset).name();
    204        this.zipEncoding = ZipEncodingHelper.getZipEncoding(charset);
    205
    206        this.recordBuf = new byte[RECORD_SIZE];
    207        this.recordsPerBlock = realBlockSize / RECORD_SIZE;
    208    }
    209
    210    /**
    211     * Constructs a new instance.
    212     *
    213     * <p>
    214     * Uses a block size of 512 bytes.
    215     * </p>
    216     *
    217     * @param os       the output stream to use
    218     * @param charset name of the encoding to use for file names
    219     * @since 1.4
    220     */
    221    public TarArchiveOutputStream(final OutputStream os, final String charset) {
    222        this(os, BLOCK_SIZE_UNSPECIFIED, charset);
    223    }
    224
    225    private void addFileTimePaxHeader(final Map<String, String> paxHeaders, final String header, final FileTime value) {
    226        if (value != null) {
    227            final Instant instant = value.toInstant();
    228            final long seconds = instant.getEpochSecond();
    229            final int nanos = instant.getNano();
    230            if (nanos == 0) {
    231                paxHeaders.put(header, String.valueOf(seconds));
    232            } else {
    233                addInstantPaxHeader(paxHeaders, header, seconds, nanos);
    234            }
    235        }
    236    }
    237
    238    private void addFileTimePaxHeaderForBigNumber(final Map<String, String> paxHeaders, final String header, final FileTime value, final long maxValue) {
    239        if (value != null) {
    240            final Instant instant = value.toInstant();
    241            final long seconds = instant.getEpochSecond();
    242            final int nanos = instant.getNano();
    243            if (nanos == 0) {
    244                addPaxHeaderForBigNumber(paxHeaders, header, seconds, maxValue);
    245            } else {
    246                addInstantPaxHeader(paxHeaders, header, seconds, nanos);
    247            }
    248        }
    249    }
    250
    251    private void addInstantPaxHeader(final Map<String, String> paxHeaders, final String header, final long seconds, final int nanos) {
    252        final BigDecimal bdSeconds = BigDecimal.valueOf(seconds);
    253        final BigDecimal bdNanos = BigDecimal.valueOf(nanos).movePointLeft(9).setScale(7, RoundingMode.DOWN);
    254        final BigDecimal timestamp = bdSeconds.add(bdNanos);
    255        paxHeaders.put(header, timestamp.toPlainString());
    256    }
    257
    258    private void addPaxHeaderForBigNumber(final Map<String, String> paxHeaders, final String header, final long value, final long maxValue) {
    259        if (value < 0 || value > maxValue) {
    260            paxHeaders.put(header, String.valueOf(value));
    261        }
    262    }
    263
    264    private void addPaxHeadersForBigNumbers(final Map<String, String> paxHeaders, final TarArchiveEntry entry) {
    265        addPaxHeaderForBigNumber(paxHeaders, "size", entry.getSize(), TarConstants.MAXSIZE);
    266        addPaxHeaderForBigNumber(paxHeaders, "gid", entry.getLongGroupId(), TarConstants.MAXID);
    267        addFileTimePaxHeaderForBigNumber(paxHeaders, "mtime", entry.getLastModifiedTime(), TarConstants.MAXSIZE);
    268        addFileTimePaxHeader(paxHeaders, "atime", entry.getLastAccessTime());
    269        if (entry.getStatusChangeTime() != null) {
    270            addFileTimePaxHeader(paxHeaders, "ctime", entry.getStatusChangeTime());
    271        } else {
    272            // ctime is usually set from creation time on platforms where the real ctime is not available
    273            addFileTimePaxHeader(paxHeaders, "ctime", entry.getCreationTime());
    274        }
    275        addPaxHeaderForBigNumber(paxHeaders, "uid", entry.getLongUserId(), TarConstants.MAXID);
    276        // libarchive extensions
    277        addFileTimePaxHeader(paxHeaders, "LIBARCHIVE.creationtime", entry.getCreationTime());
    278        // star extensions by Jorg Schilling
    279        addPaxHeaderForBigNumber(paxHeaders, "SCHILY.devmajor", entry.getDevMajor(), TarConstants.MAXID);
    280        addPaxHeaderForBigNumber(paxHeaders, "SCHILY.devminor", entry.getDevMinor(), TarConstants.MAXID);
    281        // there is no PAX header for file mode
    282        failForBigNumber("mode", entry.getMode(), TarConstants.MAXID);
    283    }
    284
    285    /**
    286     * Closes the underlying OutputStream.
    287     *
    288     * @throws IOException on error
    289     */
    290    @Override
    291    public void close() throws IOException {
    292        try {
    293            if (!isFinished()) {
    294                finish();
    295            }
    296        } finally {
    297            super.close();
    298        }
    299    }
    300
    301    /**
    302     * Closes an entry. This method MUST be called for all file entries that contain data. The reason is that we must buffer data written to the stream in order
    303     * to satisfy the buffer's record based writes. Thus, there may be data fragments still being assembled that must be written to the output stream before
    304     * this entry is closed and the next entry written.
    305     *
    306     * @throws IOException on error
    307     */
    308    @Override
    309    public void closeArchiveEntry() throws IOException {
    310        checkFinished();
    311        if (!haveUnclosedEntry) {
    312            throw new IOException("No current entry to close");
    313        }
    314        ((FixedLengthBlockOutputStream) out).flushBlock();
    315        if (currBytes < currSize) {
    316            throw new IOException(
    317                    "Entry '" + currName + "' closed at '" + currBytes + "' before the '" + currSize + "' bytes specified in the header were written");
    318        }
    319        recordsWritten += currSize / RECORD_SIZE;
    320
    321        if (0 != currSize % RECORD_SIZE) {
    322            recordsWritten++;
    323        }
    324        haveUnclosedEntry = false;
    325    }
    326
    327    @Override
    328    public TarArchiveEntry createArchiveEntry(final File inputFile, final String entryName) throws IOException {
    329        checkFinished();
    330        return new TarArchiveEntry(inputFile, entryName);
    331    }
    332
    333    @Override
    334    public TarArchiveEntry createArchiveEntry(final Path inputPath, final String entryName, final LinkOption... options) throws IOException {
    335        checkFinished();
    336        return new TarArchiveEntry(inputPath, entryName, options);
    337    }
    338
    339    private byte[] encodeExtendedPaxHeadersContents(final Map<String, String> headers) {
    340        final StringWriter w = new StringWriter();
    341        headers.forEach((k, v) -> {
    342            int len = k.length() + v.length() + 3 /* blank, equals and newline */
    343                    + 2 /* guess 9 < actual length < 100 */;
    344            String line = len + " " + k + "=" + v + "\n";
    345            int actualLength = line.getBytes(UTF_8).length;
    346            while (len != actualLength) {
    347                // Adjust for cases where length < 10 or > 100
    348                // or where UTF-8 encoding isn't a single octet
    349                // per character.
    350                // Must be in loop as size may go from 99 to 100 in
    351                // first pass, so we'd need a second.
    352                len = actualLength;
    353                line = len + " " + k + "=" + v + "\n";
    354                actualLength = line.getBytes(UTF_8).length;
    355            }
    356            w.write(line);
    357        });
    358        return w.toString().getBytes(UTF_8);
    359    }
    360
    361    private void failForBigNumber(final String field, final long value, final long maxValue) {
    362        failForBigNumber(field, value, maxValue, "");
    363    }
    364
    365    private void failForBigNumber(final String field, final long value, final long maxValue, final String additionalMsg) {
    366        if (value < 0 || value > maxValue) {
    367            throw new IllegalArgumentException(field + " '" + value // NOSONAR
    368                    + "' is too big ( > " + maxValue + " )." + additionalMsg);
    369        }
    370    }
    371
    372    private void failForBigNumbers(final TarArchiveEntry entry) {
    373        failForBigNumber("entry size", entry.getSize(), TarConstants.MAXSIZE);
    374        failForBigNumberWithPosixMessage("group id", entry.getLongGroupId(), TarConstants.MAXID);
    375        failForBigNumber("last modification time", FileTimes.toUnixTime(entry.getLastModifiedTime()), TarConstants.MAXSIZE);
    376        failForBigNumber("user id", entry.getLongUserId(), TarConstants.MAXID);
    377        failForBigNumber("mode", entry.getMode(), TarConstants.MAXID);
    378        failForBigNumber("major device number", entry.getDevMajor(), TarConstants.MAXID);
    379        failForBigNumber("minor device number", entry.getDevMinor(), TarConstants.MAXID);
    380    }
    381
    382    private void failForBigNumberWithPosixMessage(final String field, final long value, final long maxValue) {
    383        failForBigNumber(field, value, maxValue, " Use STAR or POSIX extensions to overcome this limit");
    384    }
    385
    386    /**
    387     * Finishes the TAR archive without closing the underlying OutputStream.
    388     *
    389     * An archive consists of a series of file entries terminated by an end-of-archive entry, which consists of two 512 blocks of zero bytes. POSIX.1 requires
    390     * two EOF records, like some other implementations.
    391     *
    392     * @throws IOException on error
    393     */
    394    @Override
    395    public void finish() throws IOException {
    396        checkFinished();
    397        if (haveUnclosedEntry) {
    398            throw new IOException("This archive contains unclosed entries.");
    399        }
    400        writeEOFRecord();
    401        writeEOFRecord();
    402        padAsNeeded();
    403        out.flush();
    404        super.finish();
    405    }
    406
    407    @Override
    408    public long getBytesWritten() {
    409        return countingOut.getByteCount();
    410    }
    411
    412    @Deprecated
    413    @Override
    414    public int getCount() {
    415        return (int) getBytesWritten();
    416    }
    417
    418    /**
    419     * Gets the record size being used by this stream's TarBuffer.
    420     *
    421     * @return The TarBuffer record size.
    422     * @deprecated TODO Add a comment.
    423     */
    424    @Deprecated
    425    public int getRecordSize() {
    426        return RECORD_SIZE;
    427    }
    428
    429    /**
    430     * Handles long file or link names according to the longFileMode setting.
    431     *
    432     * <p>
    433     * I.e. if the given name is too long to be written to a plain tar header then
    434     * <ul>
    435     * <li>it creates a pax header who's name is given by the paxHeaderName parameter if longFileMode is POSIX</li>
    436     * <li>it creates a GNU longlink entry who's type is given by the linkType parameter if longFileMode is GNU</li>
    437     * <li>it throws an exception if longFileMode is ERROR</li>
    438     * <li>it truncates the name if longFileMode is TRUNCATE</li>
    439     * </ul>
    440     * </p>
    441     *
    442     * @param entry         entry the name belongs to
    443     * @param name          the name to write
    444     * @param paxHeaders    current map of pax headers
    445     * @param paxHeaderName name of the pax header to write
    446     * @param linkType      type of the GNU entry to write
    447     * @param fieldName     the name of the field
    448     * @throws IllegalArgumentException if the {@link TarArchiveOutputStream#longFileMode} equals {@link TarArchiveOutputStream#LONGFILE_ERROR} and the file
    449     *                                  name is too long
    450     * @return whether a pax header has been written.
    451     */
    452    private boolean handleLongName(final TarArchiveEntry entry, final String name, final Map<String, String> paxHeaders, final String paxHeaderName,
    453            final byte linkType, final String fieldName) throws IOException {
    454        final ByteBuffer encodedName = zipEncoding.encode(name);
    455        final int len = encodedName.limit() - encodedName.position();
    456        if (len >= TarConstants.NAMELEN) {
    457
    458            if (longFileMode == LONGFILE_POSIX) {
    459                paxHeaders.put(paxHeaderName, name);
    460                return true;
    461            }
    462            if (longFileMode == LONGFILE_GNU) {
    463                // create a TarEntry for the LongLink, the contents
    464                // of which are the link's name
    465                final TarArchiveEntry longLinkEntry = new TarArchiveEntry(TarConstants.GNU_LONGLINK, linkType);
    466
    467                longLinkEntry.setSize(len + 1L); // +1 for NUL
    468                transferModTime(entry, longLinkEntry);
    469                putArchiveEntry(longLinkEntry);
    470                write(encodedName.array(), encodedName.arrayOffset(), len);
    471                write(0); // NUL terminator
    472                closeArchiveEntry();
    473            } else if (longFileMode != LONGFILE_TRUNCATE) {
    474                throw new IllegalArgumentException(fieldName + " '" + name // NOSONAR
    475                        + "' is too long ( > " + TarConstants.NAMELEN + " bytes)");
    476            }
    477        }
    478        return false;
    479    }
    480
    481    private void padAsNeeded() throws IOException {
    482        final int start = Math.toIntExact(recordsWritten % recordsPerBlock);
    483        if (start != 0) {
    484            for (int i = start; i < recordsPerBlock; i++) {
    485                writeEOFRecord();
    486            }
    487        }
    488    }
    489
    490    /**
    491     * Puts an entry on the output stream. This writes the entry's header record and positions the output stream for writing the contents of the entry. Once
    492     * this method is called, the stream is ready for calls to write() to write the entry's contents. Once the contents are written, closeArchiveEntry()
    493     * <B>MUST</B> be called to ensure that all buffered data is completely written to the output stream.
    494     *
    495     * @param archiveEntry The TarEntry to be written to the archive.
    496     * @throws IOException              on error
    497     * @throws ClassCastException       if archiveEntry is not an instance of TarArchiveEntry
    498     * @throws IllegalArgumentException if the {@link TarArchiveOutputStream#longFileMode} equals {@link TarArchiveOutputStream#LONGFILE_ERROR} and the file
    499     *                                  name is too long
    500     * @throws IllegalArgumentException if the {@link TarArchiveOutputStream#bigNumberMode} equals {@link TarArchiveOutputStream#BIGNUMBER_ERROR} and one of the
    501     *                                  numeric values exceeds the limits of a traditional tar header.
    502     */
    503    @Override
    504    public void putArchiveEntry(final TarArchiveEntry archiveEntry) throws IOException {
    505        checkFinished();
    506        if (archiveEntry.isGlobalPaxHeader()) {
    507            final byte[] data = encodeExtendedPaxHeadersContents(archiveEntry.getExtraPaxHeaders());
    508            archiveEntry.setSize(data.length);
    509            archiveEntry.writeEntryHeader(recordBuf, zipEncoding, bigNumberMode == BIGNUMBER_STAR);
    510            writeRecord(recordBuf);
    511            currSize = archiveEntry.getSize();
    512            currBytes = 0;
    513            this.haveUnclosedEntry = true;
    514            write(data);
    515            closeArchiveEntry();
    516        } else {
    517            final Map<String, String> paxHeaders = new HashMap<>();
    518            final String entryName = archiveEntry.getName();
    519            final boolean paxHeaderContainsPath = handleLongName(archiveEntry, entryName, paxHeaders, "path", TarConstants.LF_GNUTYPE_LONGNAME, "file name");
    520            final String linkName = archiveEntry.getLinkName();
    521            final boolean paxHeaderContainsLinkPath = linkName != null && !linkName.isEmpty()
    522                    && handleLongName(archiveEntry, linkName, paxHeaders, "linkpath", TarConstants.LF_GNUTYPE_LONGLINK, "link name");
    523
    524            if (bigNumberMode == BIGNUMBER_POSIX) {
    525                addPaxHeadersForBigNumbers(paxHeaders, archiveEntry);
    526            } else if (bigNumberMode != BIGNUMBER_STAR) {
    527                failForBigNumbers(archiveEntry);
    528            }
    529
    530            if (addPaxHeadersForNonAsciiNames && !paxHeaderContainsPath && !ASCII.canEncode(entryName)) {
    531                paxHeaders.put("path", entryName);
    532            }
    533
    534            if (addPaxHeadersForNonAsciiNames && !paxHeaderContainsLinkPath && (archiveEntry.isLink() || archiveEntry.isSymbolicLink())
    535                    && !ASCII.canEncode(linkName)) {
    536                paxHeaders.put("linkpath", linkName);
    537            }
    538            paxHeaders.putAll(archiveEntry.getExtraPaxHeaders());
    539
    540            if (!paxHeaders.isEmpty()) {
    541                writePaxHeaders(archiveEntry, entryName, paxHeaders);
    542            }
    543
    544            archiveEntry.writeEntryHeader(recordBuf, zipEncoding, bigNumberMode == BIGNUMBER_STAR);
    545            writeRecord(recordBuf);
    546
    547            currBytes = 0;
    548
    549            if (archiveEntry.isDirectory()) {
    550                currSize = 0;
    551            } else {
    552                currSize = archiveEntry.getSize();
    553            }
    554            currName = entryName;
    555            haveUnclosedEntry = true;
    556        }
    557    }
    558
    559    /**
    560     * Sets whether to add a PAX extension header for non-ASCII file names.
    561     *
    562     * @param b whether to add a PAX extension header for non-ASCII file names.
    563     * @since 1.4
    564     */
    565    public void setAddPaxHeadersForNonAsciiNames(final boolean b) {
    566        addPaxHeadersForNonAsciiNames = b;
    567    }
    568
    569    /**
    570     * Sets the big number mode. This can be BIGNUMBER_ERROR(0), BIGNUMBER_STAR(1) or BIGNUMBER_POSIX(2). This specifies the treatment of big files (sizes &gt;
    571     * TarConstants.MAXSIZE) and other numeric values too big to fit into a traditional tar header. Default is BIGNUMBER_ERROR.
    572     *
    573     * @param bigNumberMode the mode to use
    574     * @since 1.4
    575     */
    576    public void setBigNumberMode(final int bigNumberMode) {
    577        this.bigNumberMode = bigNumberMode;
    578    }
    579
    580    /**
    581     * Sets the long file mode. This can be LONGFILE_ERROR(0), LONGFILE_TRUNCATE(1), LONGFILE_GNU(2) or LONGFILE_POSIX(3). This specifies the treatment of long
    582     * file names (names &gt;= TarConstants.NAMELEN). Default is LONGFILE_ERROR.
    583     *
    584     * @param longFileMode the mode to use
    585     */
    586    public void setLongFileMode(final int longFileMode) {
    587        this.longFileMode = longFileMode;
    588    }
    589
    590    /**
    591     * Tests whether the character could lead to problems when used inside a TarArchiveEntry name for a PAX header.
    592     *
    593     * @return true if the character could lead to problems when used inside a TarArchiveEntry name for a PAX header.
    594     */
    595    private boolean shouldBeReplaced(final char c) {
    596        return c == 0 // would be read as Trailing null
    597                || c == '/' // when used as last character TAE will consider the PAX header a directory
    598                || c == '\\'; // same as '/' as slashes get "normalized" on Windows
    599    }
    600
    601    private String stripTo7Bits(final String name) {
    602        final int length = name.length();
    603        final StringBuilder result = new StringBuilder(length);
    604        for (int i = 0; i < length; i++) {
    605            final char stripped = (char) (name.charAt(i) & 0x7F);
    606            if (shouldBeReplaced(stripped)) {
    607                result.append("_");
    608            } else {
    609                result.append(stripped);
    610            }
    611        }
    612        return result.toString();
    613    }
    614
    615    private void transferModTime(final TarArchiveEntry from, final TarArchiveEntry to) {
    616        long fromModTimeSeconds = FileTimes.toUnixTime(from.getLastModifiedTime());
    617        if (fromModTimeSeconds < 0 || fromModTimeSeconds > TarConstants.MAXSIZE) {
    618            fromModTimeSeconds = 0;
    619        }
    620        to.setLastModifiedTime(FileTimes.fromUnixTime(fromModTimeSeconds));
    621    }
    622
    623    /**
    624     * Writes bytes to the current tar archive entry. This method is aware of the current entry and will throw an exception if you attempt to write bytes past
    625     * the length specified for the current entry.
    626     *
    627     * @param wBuf       The buffer to write to the archive.
    628     * @param wOffset    The offset in the buffer from which to get bytes.
    629     * @param numToWrite The number of bytes to write.
    630     * @throws IOException on error
    631     */
    632    @Override
    633    public void write(final byte[] wBuf, final int wOffset, final int numToWrite) throws IOException {
    634        if (!haveUnclosedEntry) {
    635            throw new IllegalStateException("No current tar entry");
    636        }
    637        if (currBytes + numToWrite > currSize) {
    638            throw new IOException(
    639                    "Request to write '" + numToWrite + "' bytes exceeds size in header of '" + currSize + "' bytes for entry '" + currName + "'");
    640        }
    641        out.write(wBuf, wOffset, numToWrite);
    642        currBytes += numToWrite;
    643    }
    644
    645    /**
    646     * Writes an EOF (end of archive) record to the tar archive. An EOF record consists of a record of all zeros.
    647     */
    648    private void writeEOFRecord() throws IOException {
    649        writeRecord(ArrayFill.fill(recordBuf, (byte) 0));
    650    }
    651
    652    /**
    653     * Writes a PAX extended header with the given map as contents.
    654     *
    655     * @since 1.4
    656     */
    657    void writePaxHeaders(final TarArchiveEntry entry, final String entryName, final Map<String, String> headers) throws IOException {
    658        String name = "./PaxHeaders.X/" + stripTo7Bits(entryName);
    659        if (name.length() >= TarConstants.NAMELEN) {
    660            name = name.substring(0, TarConstants.NAMELEN - 1);
    661        }
    662        final TarArchiveEntry pex = new TarArchiveEntry(name, TarConstants.LF_PAX_EXTENDED_HEADER_LC);
    663        transferModTime(entry, pex);
    664
    665        final byte[] data = encodeExtendedPaxHeadersContents(headers);
    666        pex.setSize(data.length);
    667        putArchiveEntry(pex);
    668        write(data);
    669        closeArchiveEntry();
    670    }
    671
    672    /**
    673     * Writes an archive record to the archive.
    674     *
    675     * @param record The record data to write to the archive.
    676     * @throws IOException on error
    677     */
    678    private void writeRecord(final byte[] record) throws IOException {
    679        if (record.length != RECORD_SIZE) {
    680            throw new IOException("Record to write has length '" + record.length + "' which is not the record size of '" + RECORD_SIZE + "'");
    681        }
    682
    683        out.write(record);
    684        recordsWritten++;
    685    }
    686}