how to read orcfile,OrcStruct is not public

[陈涛]

 i am trying to write orcfile(snappy) instead of sequencefile(lzo) in 
mapreduce,but OrcStruct is not public include getFieldValue method:
class OrcStruct implements Writable {

  private Object[] fields;

  OrcStruct(int children) {
    fields = new Object[children];
  }

  Object getFieldValue(int fieldIndex) {
    return fields[fieldIndex];
  }
}

so,how can i read orcfile?