ActivityObjectConverterProcessor.java

/*
Licensed to the Apache Software Foundation (ASF) under one
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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
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  http://www.apache.org/licenses/LICENSE-2.0

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*/

package org.apache.streams.converter;

import org.apache.streams.core.StreamsDatum;
import org.apache.streams.core.StreamsProcessor;
import org.apache.streams.core.util.DatumUtils;
import org.apache.streams.pojo.json.ActivityObject;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.LinkedList;
import java.util.List;

/**
 * ActivityObjectConverterProcessor is a utility processor for converting any datum document
 * to an Activity.
 *
 * <p/>
 * By default it will handle string json and objectnode representation of existing Activities,
 * translating them into the POJO representation(s) preferred by each registered/detected
 * ActivityConverter.
 *
 * <p/>
 * To use this capability without a dedicated stream processor, just use ActivityConverterUtil.
 */
public class ActivityObjectConverterProcessor implements StreamsProcessor {

  public static final String STREAMS_ID = "ActivityObjectConverterProcessor";

  private static final Logger LOGGER = LoggerFactory.getLogger(ActivityObjectConverterProcessor.class);

  private ActivityObjectConverterUtil converterUtil;

  private ActivityObjectConverterProcessorConfiguration configuration;

  public ActivityObjectConverterProcessor() {
  }

  public ActivityObjectConverterProcessor(ActivityObjectConverterProcessorConfiguration configuration) {
    this.configuration = configuration;
  }

  @Override
  public String getId() {
    return STREAMS_ID;
  }

  @Override
  public List<StreamsDatum> process(StreamsDatum entry) {

    List<StreamsDatum> result = new LinkedList<>();
    Object document = entry.getDocument();

    try {

      // first determine which classes this document might actually be
      ActivityObject activityObject = converterUtil.convert(document);

      StreamsDatum datum = DatumUtils.cloneDatum(entry);
      datum.setId(activityObject.getId());
      datum.setDocument(activityObject);
      result.add(datum);

    } catch ( Exception ex ) {
      LOGGER.warn("General exception in process! " + ex.getMessage());
    }

    return result;

  }

  @Override
  public void prepare(Object configurationObject) {
    if( configurationObject instanceof ActivityObjectConverterProcessorConfiguration) {
      converterUtil = ActivityObjectConverterUtil.getInstance((ActivityObjectConverterProcessorConfiguration) configurationObject);
    } else {
      converterUtil = ActivityObjectConverterUtil.getInstance();
    }
  }

  @Override
  public void cleanUp() {

  }

}