Github user rmetzger commented on a diff in the pull request:
https://github.com/apache/flink/pull/1771#discussion_r56156990
--- Diff:
flink-streaming-connectors/flink-connector-cassandra/src/main/java/org/apache/flink/batch/connectors/cassandra/CassandraInputFormat.java
---
@@ -0,0 +1,129 @@
+/*
+ * 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.batch.connectors.cassandra;
+
+import com.datastax.driver.core.Cluster;
+import com.datastax.driver.core.ResultSet;
+import com.datastax.driver.core.Row;
+import com.datastax.driver.core.Session;
+import com.google.common.base.Strings;
+import org.apache.flink.api.common.io.DefaultInputSplitAssigner;
+import org.apache.flink.api.common.io.NonParallelInput;
+import org.apache.flink.api.common.io.RichInputFormat;
+import org.apache.flink.api.common.io.statistics.BaseStatistics;
+import org.apache.flink.api.java.tuple.Tuple;
+import org.apache.flink.configuration.Configuration;
+import org.apache.flink.core.io.GenericInputSplit;
+import org.apache.flink.core.io.InputSplit;
+import org.apache.flink.core.io.InputSplitAssigner;
+import org.apache.flink.streaming.connectors.cassandra.ClusterBuilder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+
+/**
+ * InputFormat to read data from Apache Cassandra and generate ${@link
Tuple}.
+ *
+ * @param <OUT> type of Tuple
+ */
+public class CassandraInputFormat<OUT extends Tuple> extends
RichInputFormat<OUT, InputSplit> implements NonParallelInput {
+ private static final Logger LOG =
LoggerFactory.getLogger(CassandraInputFormat.class);
+
+ private final String query;
+ private final ClusterBuilder builder;
+
+ private transient Cluster cluster;
+ private transient Session session;
+ private transient ResultSet resultSet;
+
+ public CassandraInputFormat(String query, ClusterBuilder builder) {
+ if (Strings.isNullOrEmpty(query)) {
+ throw new IllegalArgumentException("Query cannot be
null or empty");
+ }
+ if (builder == null) {
+ throw new IllegalArgumentException("Builder cannot be
null.");
+ }
+ this.query = query;
+ this.builder = builder;
+ }
+
+ @Override
+ public void configure(Configuration parameters) {
+ this.cluster = builder.getCluster();
+ }
+
+ @Override
+ public BaseStatistics getStatistics(BaseStatistics cachedStatistics)
throws IOException {
+ return cachedStatistics;
+ }
+
+ /**
+ * Opens a Session and executes the query.
+ *
+ * @param ignored
+ * @throws IOException
+ */
+ @Override
+ public void open(InputSplit ignored) throws IOException {
+ this.session = cluster.connect();
+ this.resultSet = session.execute(query);
+ }
+
+ @Override
+ public boolean reachedEnd() throws IOException {
+ return resultSet.isExhausted();
+ }
+
+ @Override
+ public OUT nextRecord(OUT reuse) throws IOException {
+ final Row item = resultSet.one();
+ for (int i = 0; i < reuse.getArity(); i++) {
+ reuse.setField(item.getObject(i), i);
+ }
+ return reuse;
+ }
+
+ @Override
+ public InputSplit[] createInputSplits(int minNumSplits) throws
IOException {
+ GenericInputSplit[] split = {new GenericInputSplit(0, 1)};
+ return split;
+ }
+
+ @Override
+ public InputSplitAssigner getInputSplitAssigner(InputSplit[]
inputSplits) {
+ return new DefaultInputSplitAssigner(inputSplits);
+ }
+
+ /**
+ * Closes all resources used.
+ */
+ @Override
+ public void close() throws IOException {
+ try {
+ session.close();
+ } catch (Exception e) {
+ LOG.info("Inputformat couldn't be closed - " +
e.getMessage());
+ }
+
+ try {
+ cluster.close();
+ } catch (Exception e) {
+ LOG.info("Inputformat couldn't be closed - " +
e.getMessage());
--- End diff --
I would add the cause in both cases.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
