ConsoleWriter.java

/*
 * 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 gobblin.writer;

import java.io.IOException;
import java.util.Map;

import lombok.extern.slf4j.Slf4j;

import gobblin.source.extractor.CheckpointableWatermark;


/**
 * A simple console writer that prints the record to stdout
 */
@Slf4j
public class ConsoleWriter<D> implements WatermarkAwareWriter<D> {
  private long _recordsWritten;

  public ConsoleWriter() {
    _recordsWritten = 0;
  }

  @Override
  public void write(D record)
      throws IOException {
    System.out.println(record);
    if (record != null) {
      log.info(record.toString());
    } else {
      log.info("null record");
    }
    ++_recordsWritten;
  }

  @Override
  public void commit()
      throws IOException {
    log.debug("Commit called.");
  }

  @Override
  public void cleanup()
      throws IOException {
    log.debug("Cleanup called.");
  }

  @Override
  public long recordsWritten() {
    return _recordsWritten;
  }

  @Override
  public long bytesWritten()
      throws IOException {
    return 0;
  }

  @Override
  public void close()
      throws IOException {
    log.debug("Close called");
  }

  @Override
  public boolean isWatermarkCapable() {
    return true;
  }


  @Override
  public void writeEnvelope(AcknowledgableRecordEnvelope<D> recordEnvelope)
      throws IOException {
    write(recordEnvelope.getRecord());
    recordEnvelope.ack();
  }

  @Override
  public Map<String, CheckpointableWatermark> getCommittableWatermark() {
    throw new UnsupportedOperationException("This writer does not keep track of committed watermarks");
  }

  @Override
  public Map<String, CheckpointableWatermark> getUnacknowledgedWatermark() {
    throw new UnsupportedOperationException("This writer does not keep track of uncommitted watermarks");
  }

}