Package org.apache.tools.tar

# Class TarBuffer

java.lang.Object
org.apache.tools.tar.TarBuffer

public class TarBuffer extends Object
The TarBuffer class implements the tar archive concept of a buffered input stream. This concept goes back to the days of blocked tape drives and special io devices. In the Java universe, the only real function that this class performs is to ensure that files have the correct "block" size, or other tars will complain.

You should never have a need to access this class directly. TarBuffers are created by Tar IO Streams.

## Field Summary

Fields
Modifier and Type
Field
Description
`static final int`
`DEFAULT_BLKSIZE`
Default block size
`static final int`
`DEFAULT_RCDSIZE`
Default record size

## Constructor Summary

Constructors
Constructor
Description
`TarBuffer(InputStream inStream)`
Constructor for a TarBuffer on an input stream.
`TarBuffer(InputStream inStream, int blockSize)`
Constructor for a TarBuffer on an input stream.
`TarBuffer(InputStream inStream, int blockSize, int recordSize)`
Constructor for a TarBuffer on an input stream.
`TarBuffer(OutputStream outStream)`
Constructor for a TarBuffer on an output stream.
`TarBuffer(OutputStream outStream, int blockSize)`
Constructor for a TarBuffer on an output stream.
`TarBuffer(OutputStream outStream, int blockSize, int recordSize)`
Constructor for a TarBuffer on an output stream.

## Method Summary

Modifier and Type
Method
Description
`void`
`close()`
Close the TarBuffer.
`int`
`getBlockSize()`
Get the TAR Buffer's block size.
`int`
`getCurrentBlockNum()`
Get the current block number, zero based.
`int`
`getCurrentRecordNum()`
Get the current record number, within the current block, zero based.
`int`
`getRecordSize()`
Get the TAR Buffer's record size.
`boolean`
`isEOFRecord(byte[] record)`
Determine if an archive record indicate End of Archive.
`byte[]`
`readRecord()`
Read a record from the input stream and return the data.
`void`
`setDebug(boolean debug)`
Set the debugging flag for the buffer.
`void`
`skipRecord()`
Skip over a record on the input stream.
`void`
`writeRecord(byte[] record)`
Write an archive record to the archive.
`void`
`writeRecord(byte[] buf, int offset)`
Write an archive record to the archive, where the record may be inside of a larger array buffer.

### Methods inherited from class java.lang.Object

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

## Field Details

### DEFAULT_RCDSIZE

public static final int DEFAULT_RCDSIZE
Default record size

See Also:
  - Constant Field Values

### DEFAULT_BLKSIZE

public static final int DEFAULT_BLKSIZE
Default block size

See Also:
  - Constant Field Values

## Constructor Details

### TarBuffer

public TarBuffer(InputStream inStream)
Constructor for a TarBuffer on an input stream.

Parameters:
  `inStream` - the input stream to use

### TarBuffer

public TarBuffer(InputStream inStream, int blockSize)
Constructor for a TarBuffer on an input stream.

Parameters:
  `inStream` - the input stream to use
  `blockSize` - the block size to use

### TarBuffer

public TarBuffer(InputStream inStream, int blockSize, int recordSize)
Constructor for a TarBuffer on an input stream.

Parameters:
  `inStream` - the input stream to use
  `blockSize` - the block size to use
  `recordSize` - the record size to use

### TarBuffer

public TarBuffer(OutputStream outStream)
Constructor for a TarBuffer on an output stream.

Parameters:
  `outStream` - the output stream to use

### TarBuffer

public TarBuffer(OutputStream outStream, int blockSize)
Constructor for a TarBuffer on an output stream.

Parameters:
  `outStream` - the output stream to use
  `blockSize` - the block size to use

### TarBuffer

public TarBuffer(OutputStream outStream, int blockSize, int recordSize)
Constructor for a TarBuffer on an output stream.

Parameters:
  `outStream` - the output stream to use
  `blockSize` - the block size to use
  `recordSize` - the record size to use

## Method Details

### getBlockSize

public int getBlockSize()
Get the TAR Buffer's block size. Blocks consist of multiple records.

Returns:
  the block size

### getRecordSize

public int getRecordSize()
Get the TAR Buffer's record size.

Returns:
  the record size

### setDebug

public void setDebug(boolean debug)
Set the debugging flag for the buffer.

Parameters:
  `debug` - If true, print debugging output.

### isEOFRecord

public boolean isEOFRecord(byte[] record)
Determine if an archive record indicate End of Archive. End of archive is indicated by a record that consists entirely of null bytes.

Parameters:
  `record` - The record data to check.
Returns:
  true if the record data is an End of Archive

### skipRecord

public void skipRecord() throws IOException
Skip over a record on the input stream.

Throws:
  `IOException` - on error

### readRecord

public byte[] readRecord() throws IOException
Read a record from the input stream and return the data.

Returns:
  The record data.
Throws:
  `IOException` - on error

### getCurrentBlockNum

public int getCurrentBlockNum()
Get the current block number, zero based.

Returns:
  The current zero based block number.

### getCurrentRecordNum

public int getCurrentRecordNum()
Get the current record number, within the current block, zero based. Thus, current offset = (currentBlockNum * recsPerBlk) + currentRecNum.

Returns:
  The current zero based record number.

### writeRecord

public void writeRecord(byte[] record) throws IOException
Write an archive record to the archive.

Parameters:
  `record` - The record data to write to the archive.
Throws:
  `IOException` - on error

### writeRecord

public void writeRecord(byte[] buf, int offset) throws IOException
Write an archive record to the archive, where the record may be inside of a larger array buffer. The buffer must be "offset plus record size" long.

Parameters:
  `buf` - The buffer containing the record data to write.
  `offset` - The offset of the record data within buf.
Throws:
  `IOException` - on error

### close

public void close() throws IOException
Close the TarBuffer. If this is an output buffer, also flush the current block before closing.

Throws:
  `IOException` - on error