public static final String readUTF(DataInput in) throws IOException {
    return decodeUTF(in.readUnsignedShort(), in);
  }
Reads a UTF format String from the DataInput Stream <code>in</code>.

@param in
         the input stream to read from
@return the next UTF String from the source stream.

@throws IOException
          If a problem occurs reading from this DataInputStream.
ql/src/java/org/apache/hadoop/hive/ql/io/NonSyncDataInputBuffer.java