public static void zero(byte[] b, int offset, int length) {
    checkPositionIndex(offset, b.length, "offset");
    checkArgument(length > 0, "length must be greater than 0");
    checkPositionIndex(offset + length, b.length, "offset + length");
    Arrays.fill(b, offset, offset + length, (byte) 0);
  }
Fill given array with zeros at the specified position.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/Bytes.java