(Java) GZip Create / Extract .gz File

Demonstrates how to compress a file to create a .gz (GZip) file.

Note: The .gz file format is a compressed file format. It contains a single file. The .gz file format is not an archive format (i.e. it does not contain a collection of files/directories such as with the .zip, .rar, or .tar file formats). GZip is often combined with TAR to create a .tgz (or .tar.gz).

Note: It is possible for a .gz to contain more than one file, but this is very uncommon.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkGzip gzip = new CkGzip();

    // File-to-file GZip:
    // Compress "hamlet.xml" to create "hamlet.xml.gz"
    boolean success = gzip.CompressFile("hamlet.xml","hamlet.xml.gz");
    if (success != true) {
        System.out.println(gzip.lastErrorText());
        return;
        }

    // File-to-file ungzip
    // Decompress "hamlet.xml.gz" to create "hamletOut.xml"
    success = gzip.UncompressFile("hamlet.xml.gz","hamletOut.xml");
    if (success != true) {
        System.out.println(gzip.lastErrorText());
        return;
        }

    // File-to-string ungzip
    // Decompress the contents of a .gz directly to a string variable:
    // The 2nd argument indicates the charset of the character
    // data after it is decompressed.
    String xmlStr;
    xmlStr = gzip.uncompressFileToString("hamlet.xml.gz","utf-8");
    if (success != true) {
        System.out.println(gzip.lastErrorText());
        return;
        }

    System.out.println(xmlStr);

    // The Chilkat GZip API provides much more flexibility than shown
    // here.  See the reference documentation at 
    // http://www.chilkatsoft.com/refdoc for more information
  }
}