Example usage for com.amazonaws.util Base16Lower encodeAsString

Introduction

In this page you can find the example usage for com.amazonaws.util Base16Lower encodeAsString.

Prototype

public static String encodeAsString(byte... bytes) 

Source Link

Document

Returns a base 16 encoded string (in lower case) of the given bytes.

Usage

From source file:com.netflix.hollow.example.consumer.infrastructure.S3BlobRetriever.java

License:Apache License

private File downloadFile(String objectName) throws IOException {
    for (int retryCount = 0; retryCount < 3; retryCount++) {
        try {/* ww  w .  j  av  a 2  s. com*/
            File tempFile = new File(System.getProperty("java.io.tmpdir"), objectName.replace('/', '-'));

            S3Object s3Object = s3.getObject(bucketName, objectName);

            MessageDigest md = MessageDigest.getInstance("MD5");
            try (InputStream is = new DigestInputStream(s3Object.getObjectContent(), md);
                    OutputStream os = new FileOutputStream(tempFile)) {
                IOUtils.copy(is, os);
            }

            String expectedMD5 = s3Object.getObjectMetadata().getETag();
            String actualMD5 = Base16Lower.encodeAsString(md.digest());

            if (!actualMD5.equals(expectedMD5))
                throw new IOException("MD5 sum did not match expected!");

            return tempFile;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    throw new IOException("Unable to successfully retrieve stream from S3 after 3 retries");
}

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