public static int toInt(byte[] bytes, int offset, final int length) {
    if (length != SIZEOF_INT || offset + length > bytes.length) {
      throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_INT);
    }
    return ConverterHolder.BEST_CONVERTER.toInt(bytes, offset, length);
  }
Converts a byte array to an int value
@param bytes  byte array
@param offset offset into array
@param length length of int (has to be {@link #SIZEOF_INT})
@return the int value
@throws IllegalArgumentException if length is not {@link #SIZEOF_INT} or if there's not enough
                                 room in the array at the offset indicated.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/Bytes.java