org.apache.tools.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().
Field Summary
protected TarBufferbuffer
protected TarEntrycurrEntry
protected booleandebug
protected intentryOffset
protected intentrySize
protected booleanhasHitEOF
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
Constructor Summary
TarInputStream(InputStream is)
Constructor for TarInputStream.
TarInputStream(InputStream is, int blockSize)
Constructor for TarInputStream.
TarInputStream(InputStream is, int blockSize, int recordSize)
Constructor for TarInputStream.
Method Summary
intavailable()
Get the available data that can be read from the current entry in the archive.
voidclose()
Closes this stream.
voidcopyEntryContents(OutputStream out)
Copies the contents of the current tar archive entry directly into an output stream.
TarEntrygetNextEntry()
Get the next entry in this tar archive.
intgetRecordSize()
Get the record size being used by this stream's TarBuffer.
voidmark(int markLimit)
Since we do not support marking just yet, we do nothing.
booleanmarkSupported()
Since we do not support marking just yet, we return false.
intread()
Reads a byte from the current tar archive entry.
intread(byte[] buf, int offset, int numToRead)
Reads bytes from the current tar archive entry.
voidreset()
Since we do not support marking just yet, we do nothing.
voidsetDebug(boolean debug)
Sets the debugging flag.
longskip(long numToSkip)
Skip bytes in the input buffer.

Field Detail

buffer

protected TarBuffer buffer

currEntry

protected TarEntry currEntry

debug

protected boolean debug

entryOffset

protected int entryOffset

entrySize

protected int 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

Method Detail

available

public int 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.

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

Throws: IOException for signature

close

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

Throws: IOException on error

copyEntryContents

public void copyEntryContents(OutputStream out)
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

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 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.

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 on error

read

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

Throws: IOException on error

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 True to turn on debugging.

skip

public long skip(long 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.

Returns: the number actually skipped

Throws: IOException on error

Copyright B) 2000-2007 Apache Software Foundation. All Rights Reserved.