org.apache.commons.compress.archivers.tar

Class TarArchiveInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.compress.archivers.ArchiveInputStream

org.apache.commons.compress.archivers.tar.TarArchiveInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class TarArchiveInputStream
extends ArchiveInputStream

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().

Constructor Summary

Constructors

Constructor and Description
TarArchiveInputStream(java.io.InputStream is) Constructor for TarInputStream.
TarArchiveInputStream(java.io.InputStream is, int blockSize) Constructor for TarInputStream.
TarArchiveInputStream(java.io.InputStream is, int blockSize, int recordSize) Constructor for TarInputStream.
TarArchiveInputStream(java.io.InputStream is, int blockSize, int recordSize, java.lang.String encoding) Constructor for TarInputStream.
TarArchiveInputStream(java.io.InputStream is, int blockSize, java.lang.String encoding) Constructor for TarInputStream.
TarArchiveInputStream(java.io.InputStream is, java.lang.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(ArchiveEntry ae) Whether this class is able to read the given entry.
void	close() Closes this stream.
TarArchiveEntry	getCurrentEntry() Get the current TAR Archive Entry that this input stream is processing
ArchiveEntry	getNextEntry() Returns the next Archive Entry in this Stream.
TarArchiveEntry	getNextTarEntry() Get the next entry in this tar archive.
int	getRecordSize() Get the record size being used by this stream's buffer.
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.
static boolean	matches(byte[] signature, int length) Checks if the signature matches what is expected for a tar file.
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.
long	skip(long n) Skips over and discards n bytes of data from this input stream.

Methods inherited from class org.apache.commons.compress.archivers.ArchiveInputStream

getBytesRead, getCount, read

Methods inherited from class java.io.InputStream

read

Methods inherited from class java.lang.Object

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

Constructor Detail

TarArchiveInputStream

public TarArchiveInputStream(java.io.InputStream is)

Constructor for TarInputStream.

Parameters:

is - the input stream to use

TarArchiveInputStream

public TarArchiveInputStream(java.io.InputStream is,
                             java.lang.String encoding)

Constructor for TarInputStream.

Parameters:

is - the input stream to use

encoding - name of the encoding to use for file names

Since:

1.4

TarArchiveInputStream

public TarArchiveInputStream(java.io.InputStream is,
                             int blockSize)

Constructor for TarInputStream.

Parameters:

is - the input stream to use

blockSize - the block size to use

TarArchiveInputStream

public TarArchiveInputStream(java.io.InputStream is,
                             int blockSize,
                             java.lang.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

Since:

1.4

TarArchiveInputStream

public TarArchiveInputStream(java.io.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

TarArchiveInputStream

public TarArchiveInputStream(java.io.InputStream is,
                             int blockSize,
                             int recordSize,
                             java.lang.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

Since:

1.4

Method Detail

close

public void close()
           throws java.io.IOException

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

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException - on error

getRecordSize

public int getRecordSize()

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

Returns:

The TarBuffer record size.

available

public int available()
              throws java.io.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 java.io.InputStream

Returns:

The number of available bytes for the current entry.

Throws:

java.io.IOException - for signature

skip

public long skip(long n)
          throws java.io.IOException

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file or end of entry before n bytes have been skipped; are only two possibilities. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

Overrides:

skip in class java.io.InputStream

Parameters:

n - the number of bytes to be skipped.

Returns:

the actual number of bytes skipped.

Throws:

java.io.IOException - if some other I/O error occurs.

markSupported

public boolean markSupported()

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

Overrides:

markSupported in class java.io.InputStream

Returns:

False.

mark

public void mark(int markLimit)

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

Overrides:

mark in class java.io.InputStream

Parameters:

markLimit - The limit to mark.

reset

public void reset()

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

Overrides:

reset in class java.io.InputStream

getNextTarEntry

public TarArchiveEntry getNextTarEntry()
                                throws java.io.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:

java.io.IOException - on error

getNextEntry

public ArchiveEntry getNextEntry()
                          throws java.io.IOException

Returns the next Archive Entry in this Stream.

Specified by:

getNextEntry in class ArchiveInputStream

Returns:

the next entry, or null if there are no more entries

Throws:

java.io.IOException - if the next entry could not be read

read

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

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:

java.io.IOException - on error

canReadEntryData

public boolean canReadEntryData(ArchiveEntry ae)

Whether this class is able to read the given entry.

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

Overrides:

canReadEntryData in class ArchiveInputStream

Parameters:

ae - the entry to test

Returns:

This implementation always returns true.

getCurrentEntry

public TarArchiveEntry getCurrentEntry()

Get the current TAR Archive Entry that this input stream is processing

Returns:

The current Archive Entry

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 check

length - the number of bytes to check

Returns:

true, if this stream is a tar archive stream, false otherwise