Package org.apache.commons.compress.archivers.tar

Class TarArchiveInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public class TarArchiveInputStream
extends ArchiveInputStream<TarArchiveEntry>
    The TarInputStream reads a UNIX tar archive as an InputStream. methods are provided to position at each successive entry in the archive, and the read each entry as a normal input stream using read().

    • Constructor Summary

      Constructors 
      Constructor Description
      TarArchiveInputStream​(java.io.InputStream inputStream)
      Constructs a new instance.
      TarArchiveInputStream​(java.io.InputStream inputStream, boolean lenient)
      Constructs a new instance.
      TarArchiveInputStream​(java.io.InputStream inputStream, int blockSize)
      Constructs a new instance.
      TarArchiveInputStream​(java.io.InputStream inputStream, int blockSize, int recordSize)
      Constructs a new instance.
      TarArchiveInputStream​(java.io.InputStream inputStream, int blockSize, int recordSize, java.lang.String encoding)
      Constructs a new instance.
      TarArchiveInputStream​(java.io.InputStream inputStream, int blockSize, int recordSize, java.lang.String encoding, boolean lenient)
      Constructs a new instance.
      TarArchiveInputStream​(java.io.InputStream inputStream, int blockSize, java.lang.String encoding)
      Constructs a new instance.
      TarArchiveInputStream​(java.io.InputStream inputStream, java.lang.String encoding)
      Constructs a new instance.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      private void applyPaxHeadersToCurrentEntry​(java.util.Map<java.lang.String,​java.lang.String> headers, java.util.List<TarArchiveStructSparse> sparseHeaders)  
      int available()
      Gets the available data that can be read from the current entry in the archive.
      private void buildSparseInputStreams()
      Build the input streams consisting of all-zero input streams and non-zero input streams.
      boolean canReadEntryData​(ArchiveEntry archiveEntry)
      Whether this class is able to read the given entry.
      void close()
      Closes this stream.
      private void consumeRemainderOfLastBlock()
      This method is invoked once the end of the archive is hit, it tries to consume the remaining bytes under the assumption that the tool creating this archive has padded the last block.
      private long getActuallySkipped​(long available, long skipped, long expected)
      For FileInputStream, the skip always return the number you input, so we need the available bytes to determine how many bytes are actually skipped
      TarArchiveEntry getCurrentEntry()
      Gets the current TAR Archive Entry that this input stream is processing
      protected byte[] getLongNameData()
      Gets the next entry in this tar archive as long name data.
      TarArchiveEntry getNextEntry()
      Gets the next TarArchiveEntry in this stream.
      TarArchiveEntry getNextTarEntry()
      Deprecated.
      Use getNextEntry().
      private byte[] getRecord()
      Gets the next record in this tar archive.
      int getRecordSize()
      Gets the record size being used by this stream's buffer.
      protected boolean isAtEOF()  
      private boolean isDirectory()  
      protected boolean isEOFRecord​(byte[] record)
      Tests if an archive record indicate End of Archive.
      void mark​(int markLimit)
      Since we do not support marking just yet, we do nothing.
      boolean markSupported()
      Since we do not support marking just yet, we return false.
      static boolean matches​(byte[] signature, int length)
      Checks if the signature matches what is expected for a tar file.
      private void paxHeaders()
      For PAX Format 0.0, the sparse headers(GNU.sparse.offset and GNU.sparse.numbytes) may appear multi times, and they look like:
      int read​(byte[] buf, int offset, int numToRead)
      Reads bytes from the current tar archive entry.
      private void readGlobalPaxHeaders()  
      private void readOldGNUSparse()
      Adds the sparse chunks from the current entry to the sparse chunks, including any additional sparse entries following the current entry.
      protected byte[] readRecord()
      Read a record from the input stream and return the data.
      private int readSparse​(byte[] buf, int offset, int numToRead)
      For sparse tar entries, there are many "holes"(consisting of all 0) in the file.
      void reset()
      Since we do not support marking just yet, we do nothing.
      protected void setAtEOF​(boolean atEof)  
      protected void setCurrentEntry​(TarArchiveEntry currEntry)  
      long skip​(long n)
      Skips over and discards n bytes of data from this input stream.
      private void skipRecordPadding()
      The last record block should be written at the full size, so skip any additional space used to fill a record after an entry.
      private long skipSparse​(long n)
      Skip n bytes from current input stream, if the current input stream doesn't have enough data to skip, jump to the next input stream and skip the rest bytes, keep doing this until total n bytes are skipped or the input streams are all skipped
      private void tryToConsumeSecondEOFRecord()
      Tries to read the next record rewinding the stream if it is not an EOF record.

      • Methods inherited from class java.io.FilterInputStream

        read

      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • smallBuf

        private final byte[] smallBuf

      • recordBuffer

        private final byte[] recordBuffer
        The buffer to store the TAR header.

      • blockSize

        private final int blockSize
        The size of a block.

      • atEof

        private boolean atEof
        True if stream is at EOF.

      • entrySize

        private long entrySize
        Size of the current .

      • entryOffset

        private long entryOffset
        How far into the entry the stream is at.

      • sparseInputStreams

        private java.util.List<java.io.InputStream> sparseInputStreams
        Input streams for reading sparse entries.

      • currentSparseInputStreamIndex

        private int currentSparseInputStreamIndex
        The index of current input stream being read when reading sparse entries.

      • currEntry

        private TarArchiveEntry currEntry
        The meta-data about the current entry.

      • zipEncoding

        private final ZipEncoding zipEncoding
        The encoding of the file.

      • globalPaxHeaders

        private java.util.Map<java.lang.String,​java.lang.String> globalPaxHeaders
        The global PAX header.

      • globalSparseHeaders

        private final java.util.List<TarArchiveStructSparse> globalSparseHeaders
        The global sparse headers, this is only used in PAX Format 0.X.

      • lenient

        private final boolean lenient

    • Constructor Detail

      • TarArchiveInputStream

        public TarArchiveInputStream​(java.io.InputStream inputStream)
        Constructs a new instance.
        Parameters:
        inputStream - the input stream to use

      • TarArchiveInputStream

        public TarArchiveInputStream​(java.io.InputStream inputStream,
                             boolean lenient)
        Constructs a new instance.
        Parameters:
        inputStream - the input stream to use
        lenient - when set to true illegal values for group/userid, mode, device numbers and timestamp will be ignored and the fields set to TarArchiveEntry.UNKNOWN. When set to false such illegal fields cause an exception instead.
        Since:
        1.19

      • TarArchiveInputStream

        public TarArchiveInputStream​(java.io.InputStream inputStream,
                             int blockSize)
        Constructs a new instance.
        Parameters:
        inputStream - the input stream to use
        blockSize - the block size to use

      • TarArchiveInputStream

        public TarArchiveInputStream​(java.io.InputStream inputStream,
                             int blockSize,
                             int recordSize)
        Constructs a new instance.
        Parameters:
        inputStream - the input stream to use
        blockSize - the block size to use
        recordSize - the record size to use

      • TarArchiveInputStream

        public TarArchiveInputStream​(java.io.InputStream inputStream,
                             int blockSize,
                             int recordSize,
                             java.lang.String encoding)
        Constructs a new instance.
        Parameters:
        inputStream - the input stream to use
        blockSize - the block size to use
        recordSize - the record size to use
        encoding - name of the encoding to use for file names
        Since:
        1.4

      • TarArchiveInputStream

        public TarArchiveInputStream​(java.io.InputStream inputStream,
                             int blockSize,
                             int recordSize,
                             java.lang.String encoding,
                             boolean lenient)
        Constructs a new instance.
        Parameters:
        inputStream - the input stream to use
        blockSize - the block size to use
        recordSize - the record size to use
        encoding - name of the encoding to use for file names
        lenient - when set to true illegal values for group/userid, mode, device numbers and timestamp will be ignored and the fields set to TarArchiveEntry.UNKNOWN. When set to false such illegal fields cause an exception instead.
        Since:
        1.19

      • TarArchiveInputStream

        public TarArchiveInputStream​(java.io.InputStream inputStream,
                             int blockSize,
                             java.lang.String encoding)
        Constructs a new instance.
        Parameters:
        inputStream - the input stream to use
        blockSize - the block size to use
        encoding - name of the encoding to use for file names
        Since:
        1.4

      • TarArchiveInputStream

        public TarArchiveInputStream​(java.io.InputStream inputStream,
                             java.lang.String encoding)
        Constructs a new instance.
        Parameters:
        inputStream - the input stream to use
        encoding - name of the encoding to use for file names
        Since:
        1.4

    • Method Detail

      • matches

        public static boolean matches​(byte[] signature,
                              int length)
        Checks if the signature matches what is expected for a tar file.
        Parameters:
        signature - the bytes to check
        length - the number of bytes to check
        Returns:
        true, if this stream is a tar archive stream, false otherwise

      • applyPaxHeadersToCurrentEntry

        private void applyPaxHeadersToCurrentEntry​(java.util.Map<java.lang.String,​java.lang.String> headers,
                                           java.util.List<TarArchiveStructSparse> sparseHeaders)
                                    throws java.io.IOException
        Throws:
        java.io.IOException

      • available

        public int available()
              throws java.io.IOException
        Gets the available data that can be read from the current entry in the archive. This does not indicate how much data is left in the entire archive, only in the current entry. This value is determined from the entry's size header field and the amount of data already read from the current entry. Integer.MAX_VALUE is returned in case more than Integer.MAX_VALUE bytes are left in the current entry in the archive.
        Overrides:
        available in class java.io.FilterInputStream
        Returns:
        The number of available bytes for the current entry.
        Throws:
        java.io.IOException - for signature

      • buildSparseInputStreams

        private void buildSparseInputStreams()
                              throws java.io.IOException
        Build the input streams consisting of all-zero input streams and non-zero input streams. When reading from the non-zero input streams, the data is actually read from the original input stream. The size of each input stream is introduced by the sparse headers.

        NOTE : Some all-zero input streams and non-zero input streams have the size of 0. We DO NOT store the 0 size input streams because they are meaningless.

        Throws:
        java.io.IOException

      • close

        public void close()
           throws java.io.IOException
        Closes this stream. Calls the TarBuffer's close() method.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Overrides:
        close in class java.io.FilterInputStream
        Throws:
        java.io.IOException - on error

      • consumeRemainderOfLastBlock

        private void consumeRemainderOfLastBlock()
                                  throws java.io.IOException
        This method is invoked once the end of the archive is hit, it tries to consume the remaining bytes under the assumption that the tool creating this archive has padded the last block.
        Throws:
        java.io.IOException

      • getActuallySkipped

        private long getActuallySkipped​(long available,
                                long skipped,
                                long expected)
                         throws java.io.IOException
        For FileInputStream, the skip always return the number you input, so we need the available bytes to determine how many bytes are actually skipped
        Parameters:
        available - available bytes returned by inputStream.available()
        skipped - skipped bytes returned by inputStream.skip()
        expected - bytes expected to skip
        Returns:
        number of bytes actually skipped
        Throws:
        java.io.IOException - if a truncated tar archive is detected

      • getCurrentEntry

        public TarArchiveEntry getCurrentEntry()
        Gets the current TAR Archive Entry that this input stream is processing
        Returns:
        The current Archive Entry

      • getLongNameData

        protected byte[] getLongNameData()
                          throws java.io.IOException
        Gets the next entry in this tar archive as long name data.
        Returns:
        The next entry in the archive as long name data, or null.
        Throws:
        java.io.IOException - on error

      • getNextEntry

        public TarArchiveEntry getNextEntry()
                             throws java.io.IOException
        Gets the next TarArchiveEntry in this stream.
        Specified by:
        getNextEntry in class ArchiveInputStream<TarArchiveEntry>
        Returns:
        the next entry, or null if there are no more entries
        Throws:
        java.io.IOException - if the next entry could not be read

      • getNextTarEntry

        @Deprecated
public TarArchiveEntry getNextTarEntry()
                                throws java.io.IOException
        Deprecated.
        Use getNextEntry().
        Gets the next entry in this tar archive. This will skip over any remaining data in the current entry, if there is one, and place the input stream at the header of the next entry, and read the header and instantiate a new TarEntry from the header bytes and return that entry. If there are no more entries in the archive, null will be returned to indicate that the end of the archive has been reached.
        Returns:
        The next TarEntry in the archive, or null.
        Throws:
        java.io.IOException - on error

      • getRecord

        private byte[] getRecord()
                  throws java.io.IOException
        Gets the next record in this tar archive. This will skip over any remaining data in the current entry, if there is one, and place the input stream at the header of the next entry.

        If there are no more entries in the archive, null will be returned to indicate that the end of the archive has been reached. At the same time the hasHitEOF marker will be set to true.

        Returns:
        The next header in the archive, or null.
        Throws:
        java.io.IOException - on error

      • getRecordSize

        public int getRecordSize()
        Gets the record size being used by this stream's buffer.
        Returns:
        The TarBuffer record size.

      • isAtEOF

        protected final boolean isAtEOF()

      • isDirectory

        private boolean isDirectory()

      • isEOFRecord

        protected boolean isEOFRecord​(byte[] record)
        Tests if an archive record indicate End of Archive. End of archive is indicated by a record that consists entirely of null bytes.
        Parameters:
        record - The record data to check.
        Returns:
        true if the record data is an End of Archive

      • mark

        public void mark​(int markLimit)
        Since we do not support marking just yet, we do nothing.
        Overrides:
        mark in class ArchiveInputStream<TarArchiveEntry>
        Parameters:
        markLimit - The limit to mark.

      • paxHeaders

        private void paxHeaders()
                 throws java.io.IOException
        For PAX Format 0.0, the sparse headers(GNU.sparse.offset and GNU.sparse.numbytes) may appear multi times, and they look like:

        GNU.sparse.size=size GNU.sparse.numblocks=numblocks repeat numblocks times GNU.sparse.offset=offset GNU.sparse.numbytes=numbytes end repeat

        For PAX Format 0.1, the sparse headers are stored in a single variable : GNU.sparse.map

        GNU.sparse.map Map of non-null data chunks. It is a string consisting of comma-separated values "offset,size[,offset-1,size-1...]"

        For PAX Format 1.X: The sparse map itself is stored in the file data block, preceding the actual file data. It consists of a series of decimal numbers delimited by newlines. The map is padded with nulls to the nearest block boundary. The first number gives the number of entries in the map. Following are map entries, each one consisting of two numbers giving the offset and size of the data block it describes.

        Throws:
        java.io.IOException

      • read

        public int read​(byte[] buf,
                int offset,
                int numToRead)
         throws java.io.IOException
        Reads bytes from the current tar archive entry.

        This method is aware of the boundaries of the current entry in the archive and will deal with them as if they were this stream's start and EOF.

        Overrides:
        read in class java.io.FilterInputStream
        Parameters:
        buf - The buffer into which to place bytes read.
        offset - The offset at which to place bytes read.
        numToRead - The number of bytes to read.
        Returns:
        The number of bytes read, or -1 at EOF.
        Throws:
        java.io.IOException - on error

      • readGlobalPaxHeaders

        private void readGlobalPaxHeaders()
                           throws java.io.IOException
        Throws:
        java.io.IOException

      • readOldGNUSparse

        private void readOldGNUSparse()
                       throws java.io.IOException
        Adds the sparse chunks from the current entry to the sparse chunks, including any additional sparse entries following the current entry.
        Throws:
        java.io.IOException - on error

      • readRecord

        protected byte[] readRecord()
                     throws java.io.IOException
        Read a record from the input stream and return the data.
        Returns:
        The record data or null if EOF has been hit.
        Throws:
        java.io.IOException - on error

      • readSparse

        private int readSparse​(byte[] buf,
                       int offset,
                       int numToRead)
                throws java.io.IOException
        For sparse tar entries, there are many "holes"(consisting of all 0) in the file. Only the non-zero data is stored in tar files, and they are stored separately. The structure of non-zero data is introduced by the sparse headers using the offset, where a block of non-zero data starts, and numbytes, the length of the non-zero data block. When reading sparse entries, the actual data is read out with "holes" and non-zero data combined together according to the sparse headers.
        Parameters:
        buf - The buffer into which to place bytes read.
        offset - The offset at which to place bytes read.
        numToRead - The number of bytes to read.
        Returns:
        The number of bytes read, or -1 at EOF.
        Throws:
        java.io.IOException - on error

      • setAtEOF

        protected final void setAtEOF​(boolean atEof)

      • setCurrentEntry

        protected final void setCurrentEntry​(TarArchiveEntry currEntry)

      • skip

        public long skip​(long n)
          throws java.io.IOException
        Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file or end of entry before n bytes have been skipped; are only two possibilities. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.
        Overrides:
        skip in class java.io.FilterInputStream
        Parameters:
        n - the number of bytes to be skipped.
        Returns:
        the actual number of bytes skipped.
        Throws:
        java.io.IOException - if a truncated tar archive is detected or some other I/O error occurs

      • skipRecordPadding

        private void skipRecordPadding()
                        throws java.io.IOException
        The last record block should be written at the full size, so skip any additional space used to fill a record after an entry.
        Throws:
        java.io.IOException - if a truncated tar archive is detected

      • skipSparse

        private long skipSparse​(long n)
                 throws java.io.IOException
        Skip n bytes from current input stream, if the current input stream doesn't have enough data to skip, jump to the next input stream and skip the rest bytes, keep doing this until total n bytes are skipped or the input streams are all skipped
        Parameters:
        n - bytes of data to skip
        Returns:
        actual bytes of data skipped
        Throws:
        java.io.IOException

      • tryToConsumeSecondEOFRecord

        private void tryToConsumeSecondEOFRecord()
                                  throws java.io.IOException
        Tries to read the next record rewinding the stream if it is not an EOF record.

        This is meant to protect against cases where a tar implementation has written only one EOF record when two are expected. Actually this won't help since a non-conforming implementation likely won't fill full blocks consisting of - by default - ten records either so we probably have already read beyond the archive anyway.

        Throws:
        java.io.IOException