void readData(String datapoint) {
int row_count = 100;
System.out.println("\n\n Readind data from con1 table =>\n");
DateSerializer dt = new DateSerializer();
LongSerializer ls = new LongSerializer();
// UUIDSerializer ud=new UUIDSerializer();
DoubleSerializer ds = new DoubleSerializer();
RangeSlicesQuery<Date, Long, Double> sl = HFactory.createRangeSlicesQuery(keyspace, dt, ls, ds);
// ColumnSliceIterator<Date, UUID, Double> csit=new ColumnSliceIterator<Date, UUID,
// Double>(sl,null,FINISH,false);
sl.setColumnFamily(datapoint).setRange(null, null, false, 10).setRowCount(row_count);
Date Lastkey = null;
/*QueryResult<ColumnSlice<UUID,Double>> qr=sl.execute();
System.out.println("\nInserted data is as follows:\n" + qr.get());*/
while (true) {
sl.setKeys(Lastkey, null);
QueryResult<OrderedRows<Date, Long, Double>> result = sl.execute();
OrderedRows<Date, Long, Double> rows = result.get();
Iterator<Row<Date, Long, Double>> rowsIterator = rows.iterator();
// we'll skip this first one, since it is the same as the last one from previous time we
// executed
if (Lastkey != null && rowsIterator != null) rowsIterator.next();
while (rowsIterator.hasNext()) {
Row<Date, Long, Double> row = rowsIterator.next();
Lastkey = row.getKey();
if (row.getColumnSlice().getColumns().isEmpty()) {
continue;
}
System.out.println(row);
}
if (rows.getCount() < row_count) break;
}
}
public List<String> queryAllRowKeys(String keyspace, int limit) {
int row_count = (limit > 100) ? 100 : limit;
List<String> results = new ArrayList<String>();
String decoded_keyspace = this.decodeKeyspace(keyspace);
// String(row), String(column_name), String(column_value)
Keyspace k = getExistingKeyspace(keyspace);
RangeSlicesQuery<String, String, String> rangeSlicesQuery =
HFactory.createRangeSlicesQuery(
k, StringSerializer.get(), StringSerializer.get(), StringSerializer.get())
.setColumnFamily("SPO")
.setRange(null, null, false, row_count)
.setRowCount(
(row_count == 1)
? 2
: row_count); // do this trick because if row_count=1 and only one "null"
// record, then stucks in a loop
String last_key = null;
while (true) {
rangeSlicesQuery.setKeys(last_key, null);
QueryResult<OrderedRows<String, String, String>> result = rangeSlicesQuery.execute();
OrderedRows<String, String, String> rows = result.get();
Iterator<Row<String, String, String>> rowsIterator = rows.iterator();
// we'll skip this first one, since it is the same as the last one from previous time we
// executed
if (last_key != null && rowsIterator != null) rowsIterator.next();
while (rowsIterator.hasNext()) {
Row<String, String, String> row = rowsIterator.next();
last_key = row.getKey();
results.add(row.getKey());
}
if (rows.getCount() < row_count) break;
}
return results;
}
// TM: added for supporting (?,?,?,g) queries
// NOTE: pass the actual name of the keyspace (hashed value in case of graphs)
public int queryEntireKeyspace(String keyspace, Writer out, int limit) throws IOException {
int row_count = (limit > 100) ? 100 : limit;
int total_row_count = 0;
String decoded_keyspace = this.decodeKeyspace(keyspace);
// String(row), String(column_name), String(column_value)
Keyspace k = getExistingKeyspace(keyspace);
RangeSlicesQuery<String, String, String> rangeSlicesQuery =
HFactory.createRangeSlicesQuery(
k, StringSerializer.get(), StringSerializer.get(), StringSerializer.get())
.setColumnFamily("SPO")
.setRange(null, null, false, Integer.MAX_VALUE)
.setRowCount(
(row_count == 1)
? 2
: row_count); // do this trick because if row_count=1 and only one "null"
// record, then stucks in a loop
String last_key = null;
while (true) {
rangeSlicesQuery.setKeys(last_key, null);
try {
QueryResult<OrderedRows<String, String, String>> result = rangeSlicesQuery.execute();
OrderedRows<String, String, String> rows = result.get();
Iterator<Row<String, String, String>> rowsIterator = rows.iterator();
// we'll skip this first one, since it is the same as the last one from previous time we
// executed
if (last_key != null && rowsIterator != null) rowsIterator.next();
while (rowsIterator.hasNext()) {
Row<String, String, String> row = rowsIterator.next();
last_key = row.getKey();
// print even if we just have row_key but none columns ?!
if (row.getColumnSlice().getColumns().isEmpty()) {
/*StringBuffer buf = new StringBuffer();
buf.append(row.getKey());
buf.append(" NULL NULL . ");
buf.append(keyspace + "\n");
out.println(buf.toString());
++total_row_count;
if( total_row_count >= limit )
return total_row_count;*/
continue;
}
for (Iterator it = row.getColumnSlice().getColumns().iterator(); it.hasNext(); ) {
HColumn c = (HColumn) it.next();
StringBuffer buf = new StringBuffer();
buf.append(row.getKey());
buf.append(" ");
buf.append(c.getName());
buf.append(" ");
buf.append(c.getValue());
buf.append(decoded_keyspace + "\n");
out.write(buf.toString());
// because the same row key can contain multiple column records, we consider a row each
// of them rather than the entire row :)
// (see how cumulusrdf flat storage works)
++total_row_count;
if (total_row_count >= limit) return total_row_count;
}
}
if (rows.getCount() < row_count) break;
} catch (Exception e) {
e.printStackTrace();
out.write("Exception message: " + e.getMessage() + "\n");
out.write("Exception: " + e.toString());
return -1;
}
}
return total_row_count;
}