public static int readAsInt(byte[] bytes, int offset, final int length) {
    if (offset + length > bytes.length) {
      throw new IllegalArgumentException("offset (" + offset + ") + length (" + length
        + ") exceed the" + " capacity of the array: " + bytes.length);
    }
    int n = 0;
    for (int i = offset; i < (offset + length); i++) {
      n <<= 8;
      n ^= bytes[i] & 0xFF;
    }
    return n;
  }
Converts a byte array to an int value
@param bytes  byte array
@param offset offset into array
@param length how many bytes should be considered for creating int
@return the int value
@throws IllegalArgumentException 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