@Override
public RowSet getNextRowSet(FetchOrientation orientation, long maxRows) throws HiveSQLException {
validateDefaultFetchOrientation(orientation);
assertState(OperationState.FINISHED);
RowSet rowSet = RowSetFactory.create(resultSchema, getProtocolVersion());
try {
/* if client is requesting fetch-from-start and its not the first time reading from this operation
* then reset the fetch position to beginning
*/
if (orientation.equals(FetchOrientation.FETCH_FIRST) && fetchStarted) {
driver.resetFetch();
}
fetchStarted = true;
driver.setMaxRows((int) maxRows);
if (driver.getResults(convey)) {
return decode(convey, rowSet);
}
return rowSet;
} catch (IOException e) {
throw new HiveSQLException(e);
} catch (CommandNeedRetryException e) {
throw new HiveSQLException(e);
} catch (Exception e) {
throw new HiveSQLException(e);
} finally {
convey.clear();
}
}
/**
* Fetches numRows rows.
*
* @param numRows Number of rows to fetch.
* @return A list of rows. The size of the list is numRows if there are at least numRows rows
* available to return. The size is smaller than numRows if there aren't enough rows. The
* list will be empty if there is no more row to fetch or numRows == 0.
* @throws HiveServerException Invalid value for numRows (numRows < 0)
*/
public List<String> fetchN(int numRows) throws HiveServerException, TException {
if (numRows < 0) {
throw new HiveServerException("Invalid argument for number of rows: " + numRows);
}
if (!isHiveQuery)
// Return no results if the last command was not a Hive query
return new Vector<String>();
Vector<String> result = new Vector<String>();
driver.setMaxRows(numRows);
try {
driver.getResults(result);
} catch (IOException e) {
throw new HiveServerException(e.getMessage());
}
return result;
}
/**
* Fetches the next row in a query result set.
*
* @return the next row in a query result set. null if there is no more row to fetch.
*/
public String fetchOne() throws HiveServerException, TException {
if (!isHiveQuery)
// Return no results if the last command was not a Hive query
return "";
Vector<String> result = new Vector<String>();
driver.setMaxRows(1);
try {
if (driver.getResults(result)) {
return result.get(0);
}
// TODO: Cannot return null here because thrift cannot handle nulls
// TODO: Returning empty string for now. Need to figure out how to
// TODO: return null in some other way
return "";
} catch (IOException e) {
throw new HiveServerException(e.getMessage());
}
}
@Override
public RowSet getNextRowSet(FetchOrientation orientation, long maxRows) throws HiveSQLException {
assertState(OperationState.FINISHED);
ArrayList<String> rows = new ArrayList<String>();
driver.setMaxRows((int) maxRows);
try {
driver.getResults(rows);
getSerDe();
StructObjectInspector soi = (StructObjectInspector) serde.getObjectInspector();
List<? extends StructField> fieldRefs = soi.getAllStructFieldRefs();
RowSet rowSet = new RowSet();
Object[] deserializedFields = new Object[fieldRefs.size()];
Object rowObj;
ObjectInspector fieldOI;
for (String rowString : rows) {
rowObj = serde.deserialize(new BytesWritable(rowString.getBytes()));
for (int i = 0; i < fieldRefs.size(); i++) {
StructField fieldRef = fieldRefs.get(i);
fieldOI = fieldRef.getFieldObjectInspector();
deserializedFields[i] =
convertLazyToJava(soi.getStructFieldData(rowObj, fieldRef), fieldOI);
}
rowSet.addRow(resultSchema, deserializedFields);
}
return rowSet;
} catch (IOException e) {
throw new HiveSQLException(e);
} catch (CommandNeedRetryException e) {
throw new HiveSQLException(e);
} catch (Exception e) {
throw new HiveSQLException(e);
}
}
