org.apache.commons.compress.archivers.tar

Class TarInputStream

public final class TarInputStream extends FilterInputStream

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().

Version: $Revision: 155439 $ $Date: 2006-08-28 08:10:02 +0200 (Mon, 28 Aug 2006) $

Author: Timothy Gerard Endres Stefano Mazzocchi Peter Donald

See Also: TarInputStream TarEntry

Field Summary
TarBuffer	m_buffer
TarEntry	m_currEntry
boolean	m_debug
int	m_entryOffset
int	m_entrySize
boolean	m_hasHitEOF
byte[]	m_oneBuf
byte[]	m_readBuf

Constructor Summary
	TarInputStream(InputStream input) Construct a TarInputStream using specified input stream and default block and record sizes.
	TarInputStream(InputStream input, int blockSize) Construct a TarInputStream using specified input stream, block size and default record sizes.
	TarInputStream(InputStream input, int blockSize, int recordSize) Construct a TarInputStream using specified input stream, block size and record sizes.

Method Summary
int	available() Get the available data that can be read from the current entry in the archive.
void	close() Closes this stream.
void	copyEntryContents(OutputStream output) Copies the contents of the current tar archive entry directly into an output stream.
protected void	debug(String message) Utility method to do debugging.
TarEntry	getNextEntry() Get the next entry in this tar archive.
int	getRecordSize() Get the record size being used by this stream's TarBuffer.
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.
int	read() Reads a byte from the current tar archive entry.
int	read(byte[] buffer) Reads bytes from the current tar archive entry.
int	read(byte[] buffer, int offset, int count) Reads bytes from the current tar archive entry.
void	reset() Since we do not support marking just yet, we do nothing.
void	setDebug(boolean debug) Sets the debugging flag.
void	skip(int numToSkip) Skip bytes in the input buffer.

Field Detail

Constructor Detail

TarInputStream

public TarInputStream(InputStream input)

Construct a TarInputStream using specified input stream and default block and record sizes.

Parameters: input stream to create TarInputStream from

TarInputStream

public TarInputStream(InputStream input, int blockSize)

Construct a TarInputStream using specified input stream, block size and default record sizes.

Parameters: input stream to create TarInputStream from blockSize the block size to use

TarInputStream

public TarInputStream(InputStream input, int blockSize, int recordSize)

Construct a TarInputStream using specified input stream, block size and record sizes.

Parameters: input stream to create TarInputStream from blockSize the block size to use recordSize the record size to use

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.

Returns: The number of available bytes for the current entry.

Throws: IOException when an IO error causes operation to fail

close

public void close()

Closes this stream. Calls the TarBuffer's close() method.

Throws: IOException when an IO error causes operation to fail

copyEntryContents

public void copyEntryContents(OutputStream output)

Copies the contents of the current tar archive entry directly into an output stream.

Parameters: output The OutputStream into which to write the entry's data.

Throws: IOException when an IO error causes operation to fail

debug

protected void debug(String message)

Utility method to do debugging. Capable of being overidden in sub-classes.

Parameters: message the message to use in debugging

getNextEntry

public TarEntry getNextEntry()

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 Description of Exception

getRecordSize

public int getRecordSize()

Get the record size being used by this stream's TarBuffer.

Returns: The TarBuffer record size.

mark

public void mark(int markLimit)

Since we do not support marking just yet, we do nothing.

Parameters: markLimit The limit to mark.

markSupported

public boolean markSupported()

Since we do not support marking just yet, we return false.

Returns: False.

read

public int read()

Reads a byte from the current tar archive entry. This method simply calls read( byte[], int, int ).

Returns: The byte read, or -1 at EOF.

Throws: IOException when an IO error causes operation to fail

read

public int read(byte[] buffer)

Reads bytes from the current tar archive entry. This method simply calls read( byte[], int, int ).

Parameters: buffer The buffer into which to place bytes read.

Returns: The number of bytes read, or -1 at EOF.

Throws: IOException when an IO error causes operation to fail

read

public int read(byte[] buffer, int offset, int count)

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.

Parameters: buffer The buffer into which to place bytes read. offset The offset at which to place bytes read. count The number of bytes to read.

Returns: The number of bytes read, or -1 at EOF.

Throws: IOException when an IO error causes operation to fail

reset

public void reset()

Since we do not support marking just yet, we do nothing.

setDebug

public void setDebug(boolean debug)

Sets the debugging flag.

Parameters: debug The new Debug value

skip

public void skip(int numToSkip)

Skip bytes in the input buffer. This skips bytes in the current entry's data, not the entire archive, and will stop at the end of the current entry's data if the number to skip extends beyond that point.

Parameters: numToSkip The number of bytes to skip.

Throws: IOException when an IO error causes operation to fail