NIFI-16189 Deprecated StreamUtils#read(InputStream,byte[] destination, int)

[dan-s1]

Summary

NIFI-16189
The implementations of the read method in org.apache.nifi.stream.io.StreamUtils and readNBytes(byte[], int, int) in java.io.Inputstream method are almost identical. The big difference is when bytes cannot be read from the InputStream where read throws an EOFException while readNBytes breaks out of the while loop and returns the number of byes read even though it may be 0 or -1. Although there is this difference, it seems where read was used in SplitPCAP and StandardLoadBalanceProtocol there are subsequent checks in the code, hence even though an exception is not thrown if there is something wrong it will be noted.

For ease of review, the implementations are brought below.

public static void read(final InputStream source, final byte[] destination, final int byteCount) throws IOException {
        if (destination.length < byteCount) {
            throw new IllegalArgumentException();
        }

        int bytesRead = 0;
        int len;
        while (bytesRead < byteCount) {
            len = source.read(destination, bytesRead, byteCount - bytesRead);
            if (len < 0) {
                throw new EOFException("Expected to consume " + byteCount + " bytes but consumed only " + bytesRead);
            }

            bytesRead += len;
        }
    } 

public int readNBytes(byte[] b, int off, int len) throws IOException {
        Objects.checkFromIndexSize(off, len, b.length);

        int n = 0;
        while (n < len) {
            int count = read(b, off + n, len - n);
            if (count < 0)
                break;
            n += count;
        }
        return n;
    }

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[exceptionfactory]

Thanks @dan-s1. On review, the change looks good. The behavioral difference is notable, but the checksum comparison in StandardLoadBalanceProtocol ensures expected behavior.