Apache Commons Compress

Apache Commons Compress supports both file streams (via compressors) and structured content (via archivers).

The library can be used for both compression and decompression operations, working with a relative large number of archive formats, being one of the well-known such solutions in the Java community.

The library isn't perfect, some problems still being under development for each archive file format, but overall, if you need to support a large number of compression formats and don't want to use bulky individual libraries for each format, the Commons Compress package might be your best answer.

Features:

• Supported archive file formats:
• 7z
• ar
• arj
• bzip2
• cpio
• DEFLATE
• gzip
• lzma
• Pack200
• snappy
• tar
• Unix dump
• XZ
• Zip

What is new in this release:

• The snappy, ar and tar inputstreams might fail to read from a non-buffered stream in certain cases.
• IOUtils#skip might skip fewer bytes than requested even though more could be read from the stream.
• ArchiveStreams now validate there is a current entry before reading or writing entry data.
• ArjArchiveInputStream#canReadEntryData tested the current entry of the stream rather than its argument.
• ChangeSet#delete and deleteDir now properly deal with unnamed entries.
• Added a few null checks to improve robustness.
• TarArchiveInputStream failed to read archives with empty gid/uid fields.
• TarArchiveInputStream now again throws an exception when it encounters a truncated archive while reading from the last entry.
• Adapted TarArchiveInputStream#skip to the modified IOUtils#skip method. Thanks to BELUGA BEHR.

What is new in version 1.7:

• Read-Only support for Snappy compression.
• Read-Only support for .Z compressed files.
• ZipFile and ZipArchiveInputStream now support reading entries compressed using the SHRINKING method.
• GzipCompressorOutputStream now supports setting the compression level and the header metadata (filename, comment, modification time, operating system and extra flags)
• ZipFile and ZipArchiveInputStream now support reading entries compressed using the IMPLODE method.
• ZipFile and the 7z file classes now implement Closeable and can be used in try-with-resources constructs.

What is new in version 1.5:

• CompressorStreamFactory has an option to create decompressing streams that decompress the full input for formats that support multiple concatenated streams.

What is new in version 1.4:

• Support for the XZ format has been added.

What is new in version 1.3:

• Support for the Pack200 format has been added.
• Read-only support for the format used by the Unix dump(8) tool has been added.

What is new in version 1.2:

• New features:
• ZipArchiveEntry has a new method getRawName that provides the original bytes that made up the name. This may allow user code to detect the encoding.
• TarArchiveEntry provides access to the flags that determine whether it is an archived symbolic link, pipe or other"uncommon" file system object.
• Fixed Bugs:
• ZipArchiveInputStream could fail with a "Truncated ZIP" error message for entries between 2 GByte and 4 GByte in size.
• TarArchiveInputStream now detects sparse entries using the oldgnu format and properly reports it cannot extract their contents.
• The Javadoc for ZipArchiveInputStream#skip now matches the implementation, the code has been made more defensive.
• ArArchiveInputStream fails if entries contain only blanks for userId or groupId.
• ZipFile may leak resources on some JDKs.
• BZip2CompressorInputStream throws IOException if underlying stream returns available() == 0. Removed the check.
• Calling close() on inputStream returned by CompressorStreamFactory.createCompressorInputStream() does not close the underlying input stream.
• TarArchiveOutputStream#finish now writes all buffered data to the stream
• Changes:
• ZipFile now implements finalize which closes the underlying file.
• Certain tar files not recognised by ArchiveStreamFactory.

Requirements:

• Java 5 or higher