org.apache.tools.tar

Class TarInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

org.apache.tools.tar.TarInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

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().

Field Summary

Fields

Modifier and Type	Field and Description
protected TarBuffer	buffer
protected TarEntry	currEntry
protected boolean	debug
protected long	entryOffset
protected long	entrySize
protected boolean	hasHitEOF
protected byte[]	oneBuf This contents of this array is not used at all in this class, it is only here to avoid repreated object creation during calls to the no-arg read method.
protected byte[]	readBuf

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor and Description
TarInputStream(InputStream is) Constructor for TarInputStream.
TarInputStream(InputStream is, int blockSize) Constructor for TarInputStream.
TarInputStream(InputStream is, int blockSize, int recordSize) Constructor for TarInputStream.
TarInputStream(InputStream is, int blockSize, int recordSize, String encoding) Constructor for TarInputStream.
TarInputStream(InputStream is, int blockSize, String encoding) Constructor for TarInputStream.
TarInputStream(InputStream is, String encoding) Constructor for TarInputStream.

Method Summary

Modifier and Type	Method and Description
int	available() Get the available data that can be read from the current entry in the archive.
boolean	canReadEntryData(TarEntry te) Whether this class is able to read the given entry.
void	close() Closes this stream.
void	copyEntryContents(OutputStream out) Copies the contents of the current tar archive entry directly into an output stream.
protected byte[]	getLongNameData() Get the next entry in this tar archive as longname data.
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[] 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	setDebug(boolean debug) Sets the debugging flag.
long	skip(long numToSkip) Skip bytes in the input buffer.

Methods inherited from class java.io.FilterInputStream

read

Methods inherited from class java.lang.Object

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

Field Detail

buffer

protected TarBuffer buffer

currEntry

protected TarEntry currEntry

debug

protected boolean debug

entryOffset

protected long entryOffset

entrySize

protected long entrySize

hasHitEOF

protected boolean hasHitEOF

oneBuf

protected byte[] oneBuf

This contents of this array is not used at all in this class, it is only here to avoid repreated object creation during calls to the no-arg read method.

readBuf

protected byte[] readBuf

Constructor Detail

TarInputStream

public TarInputStream(InputStream is)

Constructor for TarInputStream.

Parameters:

is - the input stream to use

TarInputStream

public TarInputStream(InputStream is,
                      int blockSize)

Constructor for TarInputStream.

Parameters:

is - the input stream to use

blockSize - the block size to use

TarInputStream

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

Constructor for TarInputStream.

Parameters:

is - the input stream to use

blockSize - the block size to use

recordSize - the record size to use

TarInputStream

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

Constructor for TarInputStream.

Parameters:

is - 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

TarInputStream

public TarInputStream(InputStream is,
                      int blockSize,
                      String encoding)

Constructor for TarInputStream.

Parameters:

is - the input stream to use

blockSize - the block size to use

encoding - name of the encoding to use for file names

TarInputStream

public TarInputStream(InputStream is,
                      String encoding)

Constructor for TarInputStream.

Parameters:

is - the input stream to use

encoding - name of the encoding to use for file names

Method Detail

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. 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 FilterInputStream

Returns:

The number of available bytes for the current entry.

Throws:

IOException - for signature

canReadEntryData

public boolean canReadEntryData(TarEntry te)

Whether this class is able to read the given entry.

May return false if the current entry is a sparse file.

close

public void close()
           throws IOException

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

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class FilterInputStream

Throws:

IOException - on error

See Also:

FilterInputStream.in

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.

Throws:

IOException - on error

getLongNameData

protected byte[] getLongNameData()
                          throws IOException

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

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.

Throws:

IOException - on error

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.

Overrides:

mark in class FilterInputStream

Parameters:

markLimit - The limit to mark.

See Also:

FilterInputStream.in, FilterInputStream.reset()

markSupported

public boolean markSupported()

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

Overrides:

markSupported in class FilterInputStream

Returns:

False.

See Also:

FilterInputStream.in, InputStream.mark(int), InputStream.reset()

read

public int read()
         throws IOException

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

Overrides:

read in class FilterInputStream

Returns:

The byte read, or -1 at EOF.

Throws:

IOException - on error

See Also:

FilterInputStream.in

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.

Overrides:

read in class 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:

IOException - on error

See Also:

FilterInputStream.in

reset

public void reset()

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

Overrides:

reset in class FilterInputStream

See Also:

FilterInputStream.in, FilterInputStream.mark(int)

setDebug

public void setDebug(boolean debug)

Sets the debugging flag.

Parameters:

debug - True to turn on debugging.

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.

Overrides:

skip in class FilterInputStream

Parameters:

numToSkip - The number of bytes to skip.

Returns:

the number actually skipped

Throws:

IOException - on error