com.ice.tar

Class TarInputStream


public 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(). Kerry Menzel <kmenzel@cfl.rr.com> Contributed the code to support file sizes greater than 2GB (longs versus ints).
Version:
$Revision: 1.9 $
Author:
Timothy Gerard Endres,
See Also:
TarBuffer, TarHeader, TarEntry

Nested Class Summary

class
TarInputStream.EntryAdapter
static interface
TarInputStream.EntryFactory
This interface is provided, with the method setEntryFactory(), to allow the programmer to have their own TarEntry subclass instantiated for the entries return from getNextEntry().

Field Summary

protected TarBuffer
buffer
protected TarEntry
currEntry
protected boolean
debug
protected TarInputStream.EntryFactory
eFactory
protected long
entryOffset
protected long
entrySize
protected boolean
hasHitEOF
protected byte[]
oneBuf
protected byte[]
readBuf

Constructor Summary

TarInputStream(InputStream is)
TarInputStream(InputStream is, int blockSize)
TarInputStream(InputStream is, int blockSize, int recordSize)

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 out)
Copies the contents of the current tar archive entry directly into an output stream.
long
getEntryPosition()
Get the number of bytes into the current TarEntry.
TarEntry
getNextEntry()
Get the next entry in this tar archive.
int
getRecordSize()
Get the record size being used by this stream's TarBuffer.
long
getStreamPosition()
Get the number of bytes into the stream we are currently at.
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[] buf)
Reads bytes from the current tar archive entry.
int
read(byte[] buf, int offset, int numToRead)
Reads bytes from the current tar archive entry.
void
reset()
Since we do not support marking just yet, we do nothing.
void
setBufferDebug(boolean debug)
Sets the debugging flag in this stream's TarBuffer.
void
setDebug(boolean debugF)
Sets the debugging flag.
void
setEntryFactory(TarInputStream.EntryFactory factory)
Sets the debugging flag.
long
skip(long numToSkip)
Skip bytes in the input buffer.

Field Details

buffer

protected TarBuffer buffer

currEntry

protected TarEntry currEntry

debug

protected boolean debug

eFactory

protected TarInputStream.EntryFactory eFactory

entryOffset

protected long entryOffset

entrySize

protected long entrySize

hasHitEOF

protected boolean hasHitEOF

oneBuf

protected byte[] oneBuf

readBuf

protected byte[] readBuf

Constructor Details

TarInputStream

public TarInputStream(InputStream is)

TarInputStream

public TarInputStream(InputStream is,
                      int blockSize)

TarInputStream

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

Method Details

available

public int available()
            throws IOException
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.

close

public void close()
            throws IOException
Closes this stream. Calls the TarBuffer's close() method.

copyEntryContents

public void copyEntryContents(OutputStream out)
            throws IOException
Copies the contents of the current tar archive entry directly into an output stream.
Parameters:
out - The OutputStream into which to write the entry's data.

getEntryPosition

public long getEntryPosition()
Get the number of bytes into the current TarEntry. This method returns the number of bytes that have been read from the current TarEntry's data.

getNextEntry

public TarEntry getNextEntry()
            throws IOException
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.

getRecordSize

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

getStreamPosition

public long getStreamPosition()
Get the number of bytes into the stream we are currently at. This method accounts for the blocking stream that tar uses, so it represents the actual position in input stream, as opposed to the place where the tar archive parsing is.

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()
            throws IOException
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.

read

public int read(byte[] buf)
            throws IOException
Reads bytes from the current tar archive entry. This method simply calls read( byte[], int, int ).
Parameters:
buf - The buffer into which to place bytes read.
Returns:
The number of bytes read, or -1 at EOF.

read

public int read(byte[] buf,
                int offset,
                int numToRead)
            throws 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.
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.

reset

public void reset()
Since we do not support marking just yet, we do nothing.

setBufferDebug

public void setBufferDebug(boolean debug)
Sets the debugging flag in this stream's TarBuffer.
Parameters:

setDebug

public void setDebug(boolean debugF)
Sets the debugging flag.
Parameters:
debugF - True to turn on debugging.

setEntryFactory

public void setEntryFactory(TarInputStream.EntryFactory factory)
Sets the debugging flag.
Parameters:

skip

public long skip(long numToSkip)
            throws IOException
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.
Returns:
The actual number of bytes skipped.

This software has been placed into the public domain.