echauchot commented on code in PR #3: URL: https://github.com/apache/flink-connector-cassandra/pull/3#discussion_r1137188385
########## flink-connector-cassandra/src/main/java/org/apache/flink/connector/cassandra/source/reader/CassandraRecordEmitter.java: ########## @@ -0,0 +1,130 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.flink.connector.cassandra.source.reader; + +import org.apache.flink.api.connector.source.SourceOutput; +import org.apache.flink.connector.base.source.reader.RecordEmitter; +import org.apache.flink.connector.cassandra.source.split.CassandraSplit; + +import com.datastax.driver.core.ColumnDefinitions; +import com.datastax.driver.core.ExecutionInfo; +import com.datastax.driver.core.ResultSet; +import com.datastax.driver.core.Row; +import com.google.common.util.concurrent.Futures; +import com.google.common.util.concurrent.ListenableFuture; + +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.function.Function; + +/** + * {@link RecordEmitter} that converts the {@link CassandraRow} read by the {@link + * CassandraSplitReader} to specified POJO and output it. This class uses the Cassandra driver + * mapper to map the row to the POJO. + * + * @param <OUT> type of POJO record to output + */ +class CassandraRecordEmitter<OUT> implements RecordEmitter<CassandraRow, OUT, CassandraSplit> { + + private final Function<ResultSet, OUT> map; + + public CassandraRecordEmitter(Function<ResultSet, OUT> map) { + this.map = map; + } + + @Override + public void emitRecord( + CassandraRow cassandraRow, SourceOutput<OUT> output, CassandraSplit cassandraSplit) { + final Row row = cassandraRow.getRow(); + // Mapping from a row to a Class<OUT> is a complex operation involving reflection API. + // It is better to use Cassandra mapper for it. + // but the mapper takes only a resultSet as input hence forging one containing only the row + ResultSet resultSet = + new ResultSet() { Review Comment: :+1: thanks for catching it -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
