org.apache.tools.tar

## Class TarBuffer

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

    public class TarBuffer
    extends java.lang.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
`static int` `DEFAULT_BLKSIZE` Default block size
`static int` `DEFAULT_RCDSIZE` Default record size

### Constructor Summary

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

### Method Summary

All Methods Instance Methods Concrete Methods
`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 Detail

#### 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 Detail

#### TarBuffer

    public TarBuffer(java.io.InputStream inStream)

Constructor for a TarBuffer on an input stream.

Parameters:
  `inStream` - the input stream to use

#### TarBuffer

    public TarBuffer(java.io.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(java.io.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(java.io.OutputStream outStream)

Constructor for a TarBuffer on an output stream.

Parameters:
  `outStream` - the output stream to use

#### TarBuffer

    public TarBuffer(java.io.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(java.io.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 Detail

#### 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 java.io.IOException

Skip over a record on the input stream.

Throws:
  `java.io.IOException` - on error

#### readRecord

    public byte[] readRecord()
                      throws java.io.IOException

Read a record from the input stream and return the data.

Returns:
  The record data.
Throws:
  `java.io.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 java.io.IOException

Write an archive record to the archive.

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

#### writeRecord

    public void writeRecord(byte[] buf,
                            int offset)
                     throws java.io.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:
  `java.io.IOException` - on error

#### close

    public void close()
               throws java.io.IOException

Close the TarBuffer. If this is an output buffer, also flush the current block before closing.

Throws:
  `java.io.IOException` - on error