(Java) Compute Glacier SHA256 Tree Hash of a File

Computes the Amazon Glacier SHA256 tree hash for a file.

Note: This example requires Chilkat v9.5.0.78 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 example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkCrypt2 crypt = new CkCrypt2();

    // For more information about Amazon Glacier tree hashes, see Computing Glacier Checksums
    // Chilkat added the "sha256-tree-hash" algorithm in v9.5.0.78 to make it easy to compute the Glacier tree hash checksum
    // of a file or from bytes in memory.
    crypt.put_HashAlgorithm("sha256-tree-hash");

    // Return the hash in lowercase hexidecimal format.
    crypt.put_EncodingMode("hexlower");

    String treeHashHex = crypt.hashFileENC("qa_data/jpg/penguins.jpg");
    System.out.println("SHA256 tree hash = " + treeHashHex);
  }
}