Upload an Archive to a Vault in S3 Glacier by Using the Amazon SDK for Java

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.glacier.GlacierClient;
import software.amazon.awssdk.services.glacier.model.UploadArchiveRequest;
import software.amazon.awssdk.services.glacier.model.UploadArchiveResponse;
import software.amazon.awssdk.services.glacier.model.GlacierException;
import java.io.File;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */
public class UploadArchive {

    static final int ONE_MB = 1024 * 1024;

    public static void main(String[] args) {
        final String usage = """

                Usage:   <strPath> <vaultName>\s

                Where:
                   strPath - The path to the archive to upload (for example, C:\\AWS\\test.pdf).
                   vaultName - The name of the vault.
                """;

        if (args.length != 2) {
            System.out.println(usage);
            System.exit(1);
        }

        String strPath = args[0];
        String vaultName = args[1];
        File myFile = new File(strPath);
        Path path = Paths.get(strPath);
        GlacierClient glacier = GlacierClient.builder()
                .region(Region.US_EAST_1)
                .build();

        String archiveId = uploadContent(glacier, path, vaultName, myFile);
        System.out.println("The ID of the archived item is " + archiveId);
        glacier.close();
    }

    public static String uploadContent(GlacierClient glacier, Path path, String vaultName, File myFile) {
        // Get an SHA-256 tree hash value.
        String checkVal = computeSHA256(myFile);
        try {
            UploadArchiveRequest uploadRequest = UploadArchiveRequest.builder()
                    .vaultName(vaultName)
                    .checksum(checkVal)
                    .build();

            UploadArchiveResponse res = glacier.uploadArchive(uploadRequest, path);
            return res.archiveId();

        } catch (GlacierException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
        return "";
    }

    private static String computeSHA256(File inputFile) {
        try {
            byte[] treeHash = computeSHA256TreeHash(inputFile);
            System.out.printf("SHA-256 tree hash = %s\n", toHex(treeHash));
            return toHex(treeHash);

        } catch (IOException ioe) {
            System.err.format("Exception when reading from file %s: %s", inputFile, ioe.getMessage());
            System.exit(-1);

        } catch (NoSuchAlgorithmException nsae) {
            System.err.format("Cannot locate MessageDigest algorithm for SHA-256: %s", nsae.getMessage());
            System.exit(-1);
        }
        return "";
    }

    public static byte[] computeSHA256TreeHash(File inputFile) throws IOException,
            NoSuchAlgorithmException {

        byte[][] chunkSHA256Hashes = getChunkSHA256Hashes(inputFile);
        return computeSHA256TreeHash(chunkSHA256Hashes);
    }

    /**
     * Computes an SHA256 checksum for each 1 MB chunk of the input file. This
     * includes the checksum for the last chunk, even if it's smaller than 1 MB.
     */
    public static byte[][] getChunkSHA256Hashes(File file) throws IOException,
            NoSuchAlgorithmException {

        MessageDigest md = MessageDigest.getInstance("SHA-256");
        long numChunks = file.length() / ONE_MB;
        if (file.length() % ONE_MB > 0) {
            numChunks++;
        }

        if (numChunks == 0) {
            return new byte[][] { md.digest() };
        }

        byte[][] chunkSHA256Hashes = new byte[(int) numChunks][];
        FileInputStream fileStream = null;

        try {
            fileStream = new FileInputStream(file);
            byte[] buff = new byte[ONE_MB];

            int bytesRead;
            int idx = 0;

            while ((bytesRead = fileStream.read(buff, 0, ONE_MB)) > 0) {
                md.reset();
                md.update(buff, 0, bytesRead);
                chunkSHA256Hashes[idx++] = md.digest();
            }

            return chunkSHA256Hashes;

        } finally {
            if (fileStream != null) {
                try {
                    fileStream.close();
                } catch (IOException ioe) {
                    System.err.printf("Exception while closing %s.\n %s", file.getName(),
                            ioe.getMessage());
                }
            }
        }
    }

    /**
     * Computes the SHA-256 tree hash for the passed array of 1 MB chunk
     * checksums.
     */
    public static byte[] computeSHA256TreeHash(byte[][] chunkSHA256Hashes)
            throws NoSuchAlgorithmException {

        MessageDigest md = MessageDigest.getInstance("SHA-256");
        byte[][] prevLvlHashes = chunkSHA256Hashes;
        while (prevLvlHashes.length > 1) {
            int len = prevLvlHashes.length / 2;
            if (prevLvlHashes.length % 2 != 0) {
                len++;
            }

            byte[][] currLvlHashes = new byte[len][];
            int j = 0;
            for (int i = 0; i < prevLvlHashes.length; i = i + 2, j++) {

                // If there are at least two elements remaining.
                if (prevLvlHashes.length - i > 1) {

                    // Calculate a digest of the concatenated nodes.
                    md.reset();
                    md.update(prevLvlHashes[i]);
                    md.update(prevLvlHashes[i + 1]);
                    currLvlHashes[j] = md.digest();

                } else { // Take care of the remaining odd chunk
                    currLvlHashes[j] = prevLvlHashes[i];
                }
            }

            prevLvlHashes = currLvlHashes;
        }

        return prevLvlHashes[0];
    }

    /**
     * Returns the hexadecimal representation of the input byte array
     */
    public static String toHex(byte[] data) {
        StringBuilder sb = new StringBuilder(data.length * 2);
        for (byte datum : data) {
            String hex = Integer.toHexString(datum & 0xFF);

            if (hex.length() == 1) {
                // Append leading zero.
                sb.append("0");
            }
            sb.append(hex);
        }
        return sb.toString().toLowerCase();
    }
}