(Java) Unzip Binary File to Stream

Demonstrates how to unzip a large binary file to a stream to allow the application to process the uncompressed bytes chunk by chunk.

Note: This example requires Chilkat v9.5.0.67 or greater.

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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 requires the Chilkat Zip API to have been previously unlocked.
    // See Unlock Chilkat Zip for sample code.

    CkZip zip = new CkZip();

    // First open a .zip.
    boolean success = zip.OpenZip("qa_data/zips/big.zip");
    if (success != true) {
        System.out.println(zip.lastErrorText());
        return;
        }

    // Get the entry to be unzipped to a stream..
    CkZipEntry entry = zip.GetEntryByIndex(0);
    if (zip.get_LastMethodSuccess() != true) {
        System.out.println(zip.lastErrorText());
        return;
        }

    CkStream dataStream = new CkStream();

    CkTask unzipTask = entry.UnzipToStreamAsync(dataStream);
    if (entry.get_LastMethodSuccess() != true) {
        System.out.println(entry.lastErrorText());

        return;
        }

    // Start the background unzip thread.
    unzipTask.Run();

    // We'll read the uncompressed data chunk-by-chunk and write to an output file.
    CkFileAccess fac = new CkFileAccess();
    success = fac.OpenForWrite("qa_output/out.dat");
    if (success != true) {
        System.out.println(fac.lastErrorText());

        return;
        }

    // Read the stream.  (this is reading the unzipped file data)
    CkBinData bd = new CkBinData();
    while (dataStream.get_EndOfStream() != true) {
        // Get the next chunk of decompressed bytes.
        dataStream.ReadBd(bd);
        // Do something with it..
        // In this simple example, we'll just write to the file.
        fac.FileWriteBd(bd,0,0);
        // Clear for the next read.
        bd.Clear();
        }

    fac.FileClose();

    System.out.println("Success.");
  }
}