| /* |
| * 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.example; |
| |
| import org.apache.flink.api.java.DataSet; |
| import org.apache.flink.api.java.ExecutionEnvironment; |
| import org.apache.flink.batch.connectors.cassandra.CassandraPojoInputFormat; |
| import org.apache.flink.batch.connectors.cassandra.CassandraPojoOutputFormat; |
| import org.apache.flink.batch.connectors.cassandra.CustomCassandraAnnotatedPojo; |
| import org.apache.flink.streaming.connectors.cassandra.ClusterBuilder; |
| |
| import com.datastax.driver.core.Cluster; |
| import com.datastax.driver.core.ConsistencyLevel; |
| import com.datastax.driver.mapping.Mapper; |
| |
| import java.util.List; |
| import java.util.UUID; |
| import java.util.stream.Collectors; |
| import java.util.stream.IntStream; |
| |
| /** |
| * This is an example showing the to use the {@link CassandraPojoInputFormat}/{@link CassandraPojoOutputFormat} in the Batch API. |
| * |
| * <p>The example assumes that a table exists in a local cassandra database, according to the following queries: |
| * CREATE KEYSPACE IF NOT EXISTS flink WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '1'}; |
| * CREATE TABLE IF NOT EXISTS flink.batches (id text, counter int, batch_id int, PRIMARY KEY(id, counter, batchId)); |
| */ |
| public class BatchPojoExample { |
| private static final String SELECT_QUERY = "SELECT id, counter, batch_id FROM flink.batches;"; |
| |
| public static void main(String[] args) throws Exception { |
| |
| ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment(); |
| env.setParallelism(1); |
| |
| List<CustomCassandraAnnotatedPojo> customCassandraAnnotatedPojos = IntStream.range(0, 20) |
| .mapToObj(x -> new CustomCassandraAnnotatedPojo(UUID.randomUUID().toString(), x, 0)) |
| .collect(Collectors.toList()); |
| |
| DataSet<CustomCassandraAnnotatedPojo> dataSet = env.fromCollection(customCassandraAnnotatedPojos); |
| |
| ClusterBuilder clusterBuilder = new ClusterBuilder() { |
| private static final long serialVersionUID = -1754532803757154795L; |
| |
| @Override |
| protected Cluster buildCluster(Cluster.Builder builder) { |
| return builder.addContactPoints("127.0.0.1").build(); |
| } |
| }; |
| |
| dataSet.output(new CassandraPojoOutputFormat<>(clusterBuilder, CustomCassandraAnnotatedPojo.class, () -> new Mapper.Option[]{Mapper.Option.saveNullFields(true)})); |
| |
| env.execute("Write"); |
| |
| /* |
| * This is for the purpose of showing an example of creating a DataSet using CassandraPojoInputFormat. |
| */ |
| DataSet<CustomCassandraAnnotatedPojo> inputDS = env |
| .createInput(new CassandraPojoInputFormat<>( |
| SELECT_QUERY, |
| clusterBuilder, |
| CustomCassandraAnnotatedPojo.class, |
| () -> new Mapper.Option[]{Mapper.Option.consistencyLevel(ConsistencyLevel.ANY)} |
| )); |
| |
| inputDS.print(); |
| } |
| } |