org.apache.commons.compress.archivers.tar

## Class TarArchiveSparseEntry

- java.lang.Object
- - org.apache.commons.compress.archivers.tar.TarArchiveSparseEntry

- All Implemented Interfaces:
    TarConstants

      public class TarArchiveSparseEntry
      extends Object
      implements TarConstants

  This class represents a sparse entry in a Tar archive.

  The C structure for a sparse entry is:

       struct posix_header {
       struct sparse sp[21]; // TarConstants.SPARSELEN_GNU_SPARSE     - offset 0
       char isextended;      // TarConstants.ISEXTENDEDLEN_GNU_SPARSE - offset 504
       };

  Whereas, "struct sparse" is:

       struct sparse {
       char offset[12];   // offset 0
       char numbytes[12]; // offset 12
       };

  Each such struct describes a block of data that has actually been written to the archive. The offset describes where in the extracted file the data is supposed to start and the numbytes provides the length of the block. When extracting the entry the gaps between the sparse structs are equivalent to areas filled with zero bytes.

- - ### Field Summary

    - ### Fields inherited from interface org.apache.commons.compress.archivers.tar.TarConstants

      `ATIMELEN_GNU, ATIMELEN_XSTAR, CHKSUM_OFFSET, CHKSUMLEN, CTIMELEN_GNU, CTIMELEN_XSTAR, DEFAULT_BLKSIZE, DEFAULT_RCDSIZE, DEVLEN, FORMAT_OLDGNU, FORMAT_POSIX, FORMAT_XSTAR, GIDLEN, GNAMELEN, GNU_LONGLINK, ISEXTENDEDLEN_GNU, ISEXTENDEDLEN_GNU_SPARSE, LF_BLK, LF_CHR, LF_CONTIG, LF_DIR, LF_FIFO, LF_GNUTYPE_LONGLINK, LF_GNUTYPE_LONGNAME, LF_GNUTYPE_SPARSE, LF_LINK, LF_NORMAL, LF_OLDNORM, LF_PAX_EXTENDED_HEADER_LC, LF_PAX_EXTENDED_HEADER_UC, LF_PAX_GLOBAL_EXTENDED_HEADER, LF_SYMLINK, LONGNAMESLEN_GNU, MAGIC_ANT, MAGIC_GNU, MAGIC_OFFSET, MAGIC_POSIX, MAGIC_XSTAR, MAGICLEN, MAXID, MAXSIZE, MODELEN, MODTIMELEN, NAMELEN, OFFSETLEN_GNU, PAD2LEN_GNU, PREFIXLEN, PREFIXLEN_XSTAR, REALSIZELEN_GNU, SIZELEN, SPARSE_HEADERS_IN_EXTENSION_HEADER, SPARSE_HEADERS_IN_OLDGNU_HEADER, SPARSE_NUMBYTES_LEN, SPARSE_OFFSET_LEN, SPARSELEN_GNU, SPARSELEN_GNU_SPARSE, UIDLEN, UNAMELEN, VERSION_ANT, VERSION_GNU_SPACE, VERSION_GNU_ZERO, VERSION_OFFSET, VERSION_POSIX, VERSIONLEN, XSTAR_MAGIC_LEN, XSTAR_MAGIC_OFFSET`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `TarArchiveSparseEntry(byte[] headerBuf)` Construct an entry from an archive's header bytes.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `List<TarArchiveStructSparse>` | `getSparseHeaders()` Obtains information about the configuration for the sparse entry.
    `boolean` | `isExtended()`

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

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

- - ### Constructor Detail

    - #### TarArchiveSparseEntry

          public TarArchiveSparseEntry(byte[] headerBuf)
                                throws IOException

      Construct an entry from an archive's header bytes. File is set to null.
      Parameters:
        `headerBuf` - The header bytes from a tar archive entry.
      Throws:
        `IOException` - on unknown format

  - ### Method Detail

    - #### isExtended

          public boolean isExtended()

    - #### getSparseHeaders

          public List<TarArchiveStructSparse> getSparseHeaders()

      Obtains information about the configuration for the sparse entry.
      Returns:
        information about the configuration for the sparse entry.
      Since:
        1.20

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