Id.java

/*
 * Copyright © 2014 - 2021 Leipzig University (Database Research Group)
 *
 * 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 org.gradoop.flink.model.impl.functions.epgm;

import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.functions.FunctionAnnotation;
import org.apache.flink.api.java.functions.KeySelector;
import org.gradoop.common.model.api.entities.Element;
import org.gradoop.common.model.impl.id.GradoopId;

/**
 * {@code element => elementId}
 *
 * @param <EL> element type
 */
@FunctionAnnotation.ForwardedFields("id->*")
public class Id<EL extends Element> implements MapFunction<EL, GradoopId>, KeySelector<EL, GradoopId> {

  @Override
  public GradoopId map(EL element) throws Exception {
    return element.getId();
  }

  @Override
  public GradoopId getKey(EL element) throws Exception {
    return element.getId();
  }

}