Class TarArchiveInputStream
java.lang.Object
java.io.InputStream
org.apache.commons.compress.archivers.ArchiveInputStream
org.apache.commons.compress.archivers.tar.TarArchiveInputStream
- All Implemented Interfaces:
Closeable
,AutoCloseable
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().
-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate final int
The size of a blockprivate TarArchiveEntry
The meta-data about the current entryprivate int
the index of current input stream being read when reading sparse entries(package private) final String
private long
How far into the entry the stream is atprivate long
Size of the current entryprivate final List<TarArchiveStructSparse>
private boolean
True if file has hit EOFprivate final InputStream
An input stream to read fromprivate final boolean
private final byte[]
The buffer to store the TAR headerprivate final int
The size the TAR headerprivate static final int
private final byte[]
private List<InputStream>
Input streams for reading sparse entriesprivate final ZipEncoding
The encoding of the file -
Constructor Summary
ConstructorsConstructorDescriptionConstructor for TarInputStream.TarArchiveInputStream
(InputStream is, boolean lenient) Constructor for TarInputStream.TarArchiveInputStream
(InputStream is, int blockSize) Constructor for TarInputStream.TarArchiveInputStream
(InputStream is, int blockSize, int recordSize) Constructor for TarInputStream.TarArchiveInputStream
(InputStream is, int blockSize, int recordSize, String encoding) Constructor for TarInputStream.TarArchiveInputStream
(InputStream is, int blockSize, int recordSize, String encoding, boolean lenient) Constructor for TarInputStream.TarArchiveInputStream
(InputStream is, int blockSize, String encoding) Constructor for TarInputStream.TarArchiveInputStream
(InputStream is, String encoding) Constructor for TarInputStream. -
Method Summary
Modifier and TypeMethodDescriptionprivate void
applyPaxHeadersToCurrentEntry
(Map<String, String> headers, List<TarArchiveStructSparse> sparseHeaders) int
Get the available data that can be read from the current entry in the archive.private void
Build the input streams consisting of all-zero input streams and non-zero input streams.boolean
Whether this class is able to read the given entry.void
close()
Closes this stream.private void
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 skippedGet the current TAR Archive Entry that this input stream is processingprotected byte[]
Get the next entry in this tar archive as longname data.Returns the next Archive Entry in this Stream.Get the next entry in this tar archive.private byte[]
Get the next record in this tar archive.int
Get the record size being used by this stream's buffer.protected final boolean
isAtEOF()
private boolean
protected boolean
isEOFRecord
(byte[] record) Determine if an archive record indicate End of Archive.void
mark
(int markLimit) Since we do not support marking just yet, we do nothing.boolean
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
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.int
read
(byte[] buf, int offset, int numToRead) Reads bytes from the current tar archive entry.private void
private void
Adds the sparse chunks from the current entry to the sparse chunks, including any additional sparse entries following the current entry.protected byte[]
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 final void
setAtEOF
(boolean b) protected final void
long
skip
(long n) Skips over and discardsn
bytes of data from this input stream.private void
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 skippedprivate void
Tries to read the next record rewinding the stream if it is not a EOF record.Methods inherited from class org.apache.commons.compress.archivers.ArchiveInputStream
count, count, getBytesRead, getCount, pushedBackBytes, read
Methods inherited from class java.io.InputStream
read, readAllBytes, readNBytes, transferTo
-
Field Details
-
SMALL_BUFFER_SIZE
private static final int SMALL_BUFFER_SIZE- See Also:
-
smallBuf
private final byte[] smallBuf -
recordSize
private final int recordSizeThe size the TAR header -
recordBuffer
private final byte[] recordBufferThe buffer to store the TAR header -
blockSize
private final int blockSizeThe size of a block -
hasHitEOF
private boolean hasHitEOFTrue if file has hit EOF -
entrySize
private long entrySizeSize of the current entry -
entryOffset
private long entryOffsetHow far into the entry the stream is at -
inputStream
An input stream to read from -
sparseInputStreams
Input streams for reading sparse entries -
currentSparseInputStreamIndex
private int currentSparseInputStreamIndexthe index of current input stream being read when reading sparse entries -
currEntry
The meta-data about the current entry -
zipEncoding
The encoding of the file -
encoding
-
globalPaxHeaders
-
globalSparseHeaders
-
lenient
private final boolean lenient
-
-
Constructor Details
-
TarArchiveInputStream
Constructor for TarInputStream.- Parameters:
is
- the input stream to use
-
TarArchiveInputStream
Constructor for TarInputStream.- Parameters:
is
- the input stream to uselenient
- when set to true illegal values for group/userid, mode, device numbers and timestamp will be ignored and the fields set toTarArchiveEntry.UNKNOWN
. When set to false such illegal fields cause an exception instead.- Since:
- 1.19
-
TarArchiveInputStream
Constructor for TarInputStream.- Parameters:
is
- the input stream to useencoding
- name of the encoding to use for file names- Since:
- 1.4
-
TarArchiveInputStream
Constructor for TarInputStream.- Parameters:
is
- the input stream to useblockSize
- the block size to use
-
TarArchiveInputStream
Constructor for TarInputStream.- Parameters:
is
- the input stream to useblockSize
- the block size to useencoding
- name of the encoding to use for file names- Since:
- 1.4
-
TarArchiveInputStream
Constructor for TarInputStream.- Parameters:
is
- the input stream to useblockSize
- the block size to userecordSize
- the record size to use
-
TarArchiveInputStream
Constructor for TarInputStream.- Parameters:
is
- the input stream to useblockSize
- the block size to userecordSize
- the record size to useencoding
- name of the encoding to use for file names- Since:
- 1.4
-
TarArchiveInputStream
public TarArchiveInputStream(InputStream is, int blockSize, int recordSize, String encoding, boolean lenient) Constructor for TarInputStream.- Parameters:
is
- the input stream to useblockSize
- the block size to userecordSize
- the record size to useencoding
- name of the encoding to use for file nameslenient
- when set to true illegal values for group/userid, mode, device numbers and timestamp will be ignored and the fields set toTarArchiveEntry.UNKNOWN
. When set to false such illegal fields cause an exception instead.- Since:
- 1.19
-
-
Method Details
-
close
Closes this stream. Calls the TarBuffer's close() method.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Overrides:
close
in classInputStream
- Throws:
IOException
- on error
-
getRecordSize
public int getRecordSize()Get the record size being used by this stream's buffer.- Returns:
- The TarBuffer record size.
-
available
Get 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 classInputStream
- Returns:
- The number of available bytes for the current entry.
- Throws:
IOException
- for signature
-
skip
Skips over and discardsn
bytes of data from this input stream. Theskip
method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly0
. This may result from any of a number of conditions; reaching end of file or end of entry beforen
bytes have been skipped; are only two possibilities. The actual number of bytes skipped is returned. Ifn
is negative, no bytes are skipped.- Overrides:
skip
in classInputStream
- Parameters:
n
- the number of bytes to be skipped.- Returns:
- the actual number of bytes skipped.
- Throws:
IOException
- if a truncated tar archive is detected or some other I/O error occurs
-
skipSparse
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:
IOException
-
markSupported
public boolean markSupported()Since we do not support marking just yet, we return false.- Overrides:
markSupported
in classInputStream
- Returns:
- False.
-
mark
public void mark(int markLimit) Since we do not support marking just yet, we do nothing.- Overrides:
mark
in classInputStream
- Parameters:
markLimit
- The limit to mark.
-
reset
public void reset()Since we do not support marking just yet, we do nothing.- Overrides:
reset
in classInputStream
-
getNextTarEntry
Get 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:
IOException
- on error
-
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.- Throws:
IOException
- if a truncated tar archive is detected
-
getActuallySkipped
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:
IOException
- if a truncated tar archive is detected
-
getLongNameData
Get the next entry in this tar archive as longname data.- Returns:
- The next entry in the archive as longname data, or null.
- Throws:
IOException
- on error
-
getRecord
Get 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:
IOException
- on error
-
isEOFRecord
protected boolean isEOFRecord(byte[] record) Determine 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
-
readRecord
Read a record from the input stream and return the data.- Returns:
- The record data or null if EOF has been hit.
- Throws:
IOException
- on error
-
readGlobalPaxHeaders
- Throws:
IOException
-
paxHeaders
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:
IOException
-
applyPaxHeadersToCurrentEntry
private void applyPaxHeadersToCurrentEntry(Map<String, String> headers, List<TarArchiveStructSparse> sparseHeaders) throws IOException- Throws:
IOException
-
readOldGNUSparse
Adds the sparse chunks from the current entry to the sparse chunks, including any additional sparse entries following the current entry.- Throws:
IOException
- on error
-
isDirectory
private boolean isDirectory() -
getNextEntry
Returns the next Archive Entry in this Stream.- Specified by:
getNextEntry
in classArchiveInputStream
- Returns:
- the next entry,
or
null
if there are no more entries - Throws:
IOException
- if the next entry could not be read
-
tryToConsumeSecondEOFRecord
Tries to read the next record rewinding the stream if it is not a 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:
IOException
-
read
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 classInputStream
- 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:
IOException
- on error
-
readSparse
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:
IOException
- on error
-
canReadEntryData
Whether this class is able to read the given entry.- Overrides:
canReadEntryData
in classArchiveInputStream
- Parameters:
ae
- the entry to test- Returns:
- The implementation will return true if the
ArchiveEntry
is an instance ofTarArchiveEntry
-
getCurrentEntry
Get the current TAR Archive Entry that this input stream is processing- Returns:
- The current Archive Entry
-
setCurrentEntry
-
isAtEOF
protected final boolean isAtEOF() -
setAtEOF
protected final void setAtEOF(boolean b) -
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.- Throws:
IOException
-
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 checklength
- the number of bytes to check- Returns:
- true, if this stream is a tar archive stream, false otherwise
-
buildSparseInputStreams
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:
IOException
-