in flink-connector-jdbc/src/main/java/org/apache/flink/connector/jdbc/JdbcInputFormat.java [283:299]
public Row nextRecord(Row reuse) throws IOException {
try {
if (!hasNext) {
return null;
}
for (int pos = 0; pos < reuse.getArity(); pos++) {
reuse.setField(pos, resultSet.getObject(pos + 1));
}
// update hasNext after we've read the record
hasNext = resultSet.next();
return reuse;
} catch (SQLException se) {
throw new IOException("Couldn't read data - " + se.getMessage(), se);
} catch (NullPointerException npe) {
throw new IOException("Couldn't access resultSet", npe);
}
}