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Gobblin Ingestion Framework

There is a newer version: 0.11.0

/*
 * Copyright (C) 2014-2016 LinkedIn Corp. All rights reserved.
 *
 * 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.
 */

package gobblin.example.simplejson;

import java.io.IOException;
import java.util.List;

import com.google.common.base.Splitter;
import com.google.common.collect.Lists;

import gobblin.configuration.ConfigurationKeys;
import gobblin.configuration.SourceState;
import gobblin.configuration.WorkUnitState;
import gobblin.source.Source;
import gobblin.source.extractor.Extractor;
import gobblin.source.workunit.Extract;
import gobblin.source.workunit.WorkUnit;


/**
 * An implementation of {@link Source} for the simple JSON example.
 *
 * 
 *   This source creates one {@link gobblin.source.workunit.WorkUnit}
 *   for each file to pull and uses the {@link SimpleJsonExtractor} to pull the data.
 * 
 *
 * @author Yinan Li
 */
public class SimpleJsonSource implements Source {

  public static final String SOURCE_FILE_KEY = "source.file";

  @Override
  public List getWorkunits(SourceState state) {
    List workUnits = Lists.newArrayList();

    if (!state.contains(ConfigurationKeys.SOURCE_FILEBASED_FILES_TO_PULL)) {
      return workUnits;
    }

    // Create a single snapshot-type extract for all files
    Extract extract = new Extract(Extract.TableType.SNAPSHOT_ONLY,
        state.getProp(ConfigurationKeys.EXTRACT_NAMESPACE_NAME_KEY, "ExampleNamespace"), "ExampleTable");

    String filesToPull = state.getProp(ConfigurationKeys.SOURCE_FILEBASED_FILES_TO_PULL);
    for (String file : Splitter.on(',').omitEmptyStrings().split(filesToPull)) {
      // Create one work unit for each file to pull
      WorkUnit workUnit = WorkUnit.create(extract);
      workUnit.setProp(SOURCE_FILE_KEY, file);
      workUnits.add(workUnit);
    }

    return workUnits;
  }

  @Override
  public Extractor getExtractor(WorkUnitState state) throws IOException {
    return new SimpleJsonExtractor(state);
  }

  @Override
  public void shutdown(SourceState state) {
    // Nothing to do
  }
}