src/main/java/net/onrc/onos/datastore/utils/ByteArrayUtil.java

package net.onrc.onos.datastore.utils;

import java.nio.ByteBuffer;

public class ByteArrayUtil {

    // Suppresses default constructor, ensuring non-instantiability.
    private ByteArrayUtil() {}

    /**
     * Returns a StringBuffer with each byte in {@code bytes}
     * converted to a String with {@link Integer#toHexString(int)},
     * separated by {@code sep}.
     *
     * @param bytes byte array to convert
     * @param sep separator between each bytes
     * @return {@code bytes} converted to a StringBuffer
     */
    public static StringBuffer toHexStringBuffer(final byte[] bytes,
	    final String sep) {
	return toHexStringBuffer(bytes, sep, new StringBuffer());
    }

    /**
     * Returns a StringBuffer with each byte in {@code bytes}
     * converted to a String with {@link Integer#toHexString(int)},
     * separated by {@code sep}.
     *
     * @param bytes byte array to convert
     * @param sep separator between each bytes
     * @param buf StringBuffer to append to.
     * @return {@code buf}
     */
    public static StringBuffer toHexStringBuffer(final byte[] bytes,
	    final String sep, final StringBuffer buf) {
	if (bytes == null) {
	    return buf;
	}

	ByteBuffer wrap = ByteBuffer.wrap(bytes);

	boolean hasWritten = false;
	while (wrap.hasRemaining()) {
	    if (hasWritten) {
		buf.append(sep);
	    }
	    buf.append(Integer.toHexString(wrap.get()));
	    hasWritten = true;
	}

	return buf;
    }
}