/** Convert a MD5MD5CRC32FileChecksum to a Json string. */
public static String toJsonString(final MD5MD5CRC32FileChecksum checksum) {
if (checksum == null) {
return null;
}
final Map<String, Object> m = new TreeMap<String, Object>();
m.put("algorithm", checksum.getAlgorithmName());
m.put("length", checksum.getLength());
m.put("bytes", StringUtils.byteToHexString(checksum.getBytes()));
return toJsonString(FileChecksum.class, m);
}
/** Convert a Json map to a MD5MD5CRC32FileChecksum. */
public static MD5MD5CRC32FileChecksum toMD5MD5CRC32FileChecksum(final Map<?, ?> json)
throws IOException {
if (json == null) {
return null;
}
final Map<?, ?> m = (Map<?, ?>) json.get(FileChecksum.class.getSimpleName());
final String algorithm = (String) m.get("algorithm");
final int length = (int) (long) (Long) m.get("length");
final byte[] bytes = StringUtils.hexStringToByte((String) m.get("bytes"));
final DataInputStream in = new DataInputStream(new ByteArrayInputStream(bytes));
final DataChecksum.Type crcType =
MD5MD5CRC32FileChecksum.getCrcTypeFromAlgorithmName(algorithm);
final MD5MD5CRC32FileChecksum checksum;
// Recreate what DFSClient would have returned.
switch (crcType) {
case CRC32:
checksum = new MD5MD5CRC32GzipFileChecksum();
break;
case CRC32C:
checksum = new MD5MD5CRC32CastagnoliFileChecksum();
break;
default:
throw new IOException("Unknown algorithm: " + algorithm);
}
checksum.readFields(in);
// check algorithm name
if (!checksum.getAlgorithmName().equals(algorithm)) {
throw new IOException(
"Algorithm not matched. Expected "
+ algorithm
+ ", Received "
+ checksum.getAlgorithmName());
}
// check length
if (length != checksum.getLength()) {
throw new IOException(
"Length not matched: length="
+ length
+ ", checksum.getLength()="
+ checksum.getLength());
}
return checksum;
}