java.lang.Object
org.apache.commons.compress.compressors.xz.XZUtils

public class XZUtils extends Object
Utility code for the xz compression format.
Since:
1.4
  • Field Details

    • fileNameUtil

      private static final FileNameUtil fileNameUtil
    • HEADER_MAGIC

      private static final byte[] HEADER_MAGIC
      XZ Header Magic Bytes begin a XZ file.

      This is a copy of org.tukaani.xz.XZ.HEADER_MAGIC in XZ for Java version 1.5.

    • cachedXZAvailability

      private static volatile XZUtils.CachedAvailability cachedXZAvailability
  • Constructor Details

    • XZUtils

      private XZUtils()
      Private constructor to prevent instantiation of this utility class.
  • Method Details

    • matches

      public static boolean matches(byte[] signature, int length)
      Checks if the signature matches what is expected for a .xz file.

      This is more or less a copy of the version found in XZCompressorInputStream but doesn't depend on the presence of XZ for Java.

      Parameters:
      signature - the bytes to check
      length - the number of bytes to check
      Returns:
      true if signature matches the .xz magic bytes, false otherwise
      Since:
      1.9
    • isXZCompressionAvailable

      public static boolean isXZCompressionAvailable()
      Are the classes required to support XZ compression available?
      Returns:
      true if the classes required to support XZ compression are available
      Since:
      1.5
    • internalIsXZCompressionAvailable

      private static boolean internalIsXZCompressionAvailable()
    • isCompressedFilename

      public static boolean isCompressedFilename(String fileName)
      Detects common xz suffixes in the given file name.
      Parameters:
      fileName - name of a file
      Returns:
      true if the file name has a common xz suffix, false otherwise
    • getUncompressedFilename

      public static String getUncompressedFilename(String fileName)
      Maps the given name of a xz-compressed file to the name that the file should have after uncompression. Commonly used file type specific suffixes like ".txz" are automatically detected and correctly mapped. For example the name "package.txz" is mapped to "package.tar". And any file names with the generic ".xz" suffix (or any other generic xz suffix) is mapped to a name without that suffix. If no xz suffix is detected, then the file name is returned unmapped.
      Parameters:
      fileName - name of a file
      Returns:
      name of the corresponding uncompressed file
    • getCompressedFilename

      public static String getCompressedFilename(String fileName)
      Maps the given file name to the name that the file should have after compression with xz. Common file types with custom suffixes for compressed versions are automatically detected and correctly mapped. For example the name "package.tar" is mapped to "package.txz". If no custom mapping is applicable, then the default ".xz" suffix is appended to the file name.
      Parameters:
      fileName - name of a file
      Returns:
      name of the corresponding compressed file
    • setCacheXZAvailablity

      public static void setCacheXZAvailablity(boolean doCache)
      Whether to cache the result of the XZ for Java check.

      This defaults to false in an OSGi environment and true otherwise.

      Parameters:
      doCache - whether to cache the result
      Since:
      1.9
    • getCachedXZAvailability

      static XZUtils.CachedAvailability getCachedXZAvailability()