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; }