Package 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 
    Modifier and Type Field Description
    static int DEFAULT_BLKSIZE
    Default block size
    static int DEFAULT_RCDSIZE
    Default record size

  • Constructor Summary

    Constructors 
    Constructor 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

    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

  • Constructor Details

    • 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 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 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