How to Compress/Decompress tar.gz files in java

My favorite is plexus-archiver - see sources on GitHub.

Another option is Apache commons-compress - (see mvnrepository).

With plexus-utils, the code for unarchiving looks like this:

final TarGZipUnArchiver ua = new TarGZipUnArchiver();
// Logging - as @Akom noted, logging is mandatory in newer versions, so you can use a code like this to configure it:
ConsoleLoggerManager manager = new ConsoleLoggerManager();
manager.initialize();
ua.enableLogging(manager.getLoggerForComponent("bla"));
// -- end of logging part
ua.setSourceFile(sourceFile);
destDir.mkdirs();
ua.setDestDirectory(destDir);
ua.extract();

Similar *Archiver classes are there for archiving.

With Maven, you can use this dependency:

<dependency>
  <groupId>org.codehaus.plexus</groupId>
  <artifactId>plexus-archiver</artifactId>
  <version>2.2</version>
</dependency>

I've written a wrapper for commons-compress called jarchivelib that makes it easy to extract or compress from and into File objects.

Example code would look like this:

File archive = new File("/home/thrau/archive.tar.gz");
File destination = new File("/home/thrau/archive/");

Archiver archiver = ArchiverFactory.createArchiver("tar", "gz");
archiver.extract(archive, destination);