StreamCreator.java

/*
 * Copyright © 2015 Cask Data, Inc.
 *
 * Licensed 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 co.cask.cdap.internal.app.deploy.pipeline;

import co.cask.cdap.api.data.stream.StreamSpecification;
import co.cask.cdap.common.conf.Constants;
import co.cask.cdap.data2.transaction.stream.StreamAdmin;
import co.cask.cdap.proto.Id;

import java.util.Properties;

/**
 * Creates streams.
 */
public class StreamCreator {

  private final Id.Namespace namespace;
  private final StreamAdmin streamAdmin;

  public StreamCreator(Id.Namespace namespace, StreamAdmin streamAdmin) {
    this.namespace = namespace;
    this.streamAdmin = streamAdmin;
  }

  /**
   * Create the given streams and the Hive tables for the streams if explore is enabled.
   *
   * @param streamSpecs the set of stream specifications for streams to be created
   * @throws Exception if there was an exception creating a stream
   */
  public void createStreams(Iterable<StreamSpecification> streamSpecs) throws Exception {
    for (StreamSpecification spec : streamSpecs) {
      Properties props = new Properties();
      if (spec.getDescription() != null) {
        props.put(Constants.Stream.DESCRIPTION, spec.getDescription());
      }
      streamAdmin.create(Id.Stream.from(namespace, spec.getName()), props);
    }
  }
}