Examples with ResultSetTypedIterator annis.sqlgen.ResultSetTypedIterator used on opensource projects

Example 1 with ResultSetTypedIterator

use of annis.sqlgen.ResultSetTypedIterator in project ANNIS by korpling.

the class QueryDaoImpl method find.

@Transactional(readOnly = true)
@Override
public boolean find(final QueryData queryData, final OutputStream out) {
    prepareTransaction(queryData);
    Boolean finished = getJdbcTemplate().execute(new ConnectionCallback<Boolean>() {

        @Override
        public Boolean doInConnection(Connection con) throws SQLException, DataAccessException {
            try (Statement stmt = con.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY)) {
                String sql = findSqlGenerator.toSql(queryData);
                PrintWriter w;
                try (ResultSet rs = stmt.executeQuery(sql)) {
                    w = new PrintWriter(new OutputStreamWriter(out, "UTF-8"));
                    ResultSetTypedIterator<Match> itMatches = new ResultSetTypedIterator<>(rs, findSqlGenerator);
                    int i = 1;
                    while (itMatches.hasNext()) {
                        // write single match to output stream
                        Match m = itMatches.next();
                        w.print(m.toString());
                        w.print("\n");
                        // flush after every 10th item
                        if (i % 10 == 0) {
                            w.flush();
                        }
                        i++;
                    }
                // end for each match
                }
                w.flush();
                return true;
            } catch (UnsupportedEncodingException ex) {
                log.error("Your system is not able to handle UTF-8 but ANNIS really needs this charset", ex);
            }
            return false;
        }
    });
    return finished;
}