BaseStringActivityConverter.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 org.apache.streams.converter;

import org.apache.streams.data.ActivityConverter;
import org.apache.streams.exceptions.ActivityConversionException;
import org.apache.streams.jackson.StreamsJacksonMapper;
import org.apache.streams.pojo.json.Activity;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.lang.NotImplementedException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.ArrayList;
import java.util.List;

/**
 * Ensures generic String Json representation of an Activity can be converted to Activity
 *
 * <p/>
 * BaseObjectNodeActivityConverter is included by default in all
 * {@link org.apache.streams.converter.ActivityConverterProcessor}
 *
 */
public class BaseStringActivityConverter implements ActivityConverter<String> {

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

  public static final Class requiredClass = String.class;

  private ObjectMapper mapper = StreamsJacksonMapper.getInstance();

  @Override
  public Class requiredClass() {
    return requiredClass;
  }

  @Override
  public String serializationFormat() {
    return null;
  }

  @Override
  public String fromActivity(Activity deserialized) throws ActivityConversionException {
    try {
      return mapper.writeValueAsString(deserialized);
    } catch (JsonProcessingException ex) {
      throw new ActivityConversionException();
    }
  }

  @Override
  public List<String> fromActivityList(List<Activity> list) {
    throw new NotImplementedException();
  }

  @Override
  public List<Activity> toActivityList(String serialized) throws ActivityConversionException {
    List<Activity> activityList = new ArrayList<>();
    try {
      activityList.add(mapper.readValue(serialized, Activity.class));
    } catch (Exception ex) {
      throw new ActivityConversionException();
    }
    return activityList;
  }

  @Override
  public List<Activity> toActivityList(List<String> list) {
    List<Activity> result = new ArrayList<>();
    for ( String item : list ) {
      try {
        result.addAll(toActivityList(item));
      } catch (ActivityConversionException ex) {
        LOGGER.trace("ActivityConversionException", ex);
      }
    }
    return result;
  }



}