    001/*
    002 * Copyright (c) 2007-2016 Concurrent, Inc. All Rights Reserved.
    003 *
    004 * Project and contact information: http://www.cascading.org/
    005 *
    006 * This file is part of the Cascading project.
    007 *
    008 * Licensed under the Apache License, Version 2.0 (the "License");
    009 * you may not use this file except in compliance with the License.
    010 * You may obtain a copy of the License at
    011 *
    012 *     http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing, software
    015 * distributed under the License is distributed on an "AS IS" BASIS,
    016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    017 * See the License for the specific language governing permissions and
    018 * limitations under the License.
    019 */
    020
    021package cascading.tuple;
    022
    023import java.io.Closeable;
    024import java.util.Iterator;
    025
    026/**
    027 * Class TupleEntryIterator provides an efficient Iterator for returning {@link TupleEntry} elements in an
    028 * underlying {@link Tuple} collection.
    029 */
    030public abstract class TupleEntryIterator implements Iterator<TupleEntry>, Closeable
    031  {
    032  /** Field entry */
    033  final TupleEntry entry;
    034
    035  /**
    036   * Constructor TupleEntryIterator creates a new TupleEntryIterator instance.
    037   *
    038   * @param fields of type Fields
    039   */
    040  public TupleEntryIterator( Fields fields )
    041    {
    042    this.entry = new TupleEntry( fields, Tuple.size( fields.size() ) );
    043    }
    044
    045  /**
    046   * Method getFields returns the fields of this TupleEntryIterator object.
    047   *
    048   * @return the fields (type Fields) of this TupleEntryIterator object.
    049   */
    050  public Fields getFields()
    051    {
    052    return entry.getFields();
    053    }
    054
    055  /**
    056   * Method getTupleEntry returns the entry of this TupleEntryIterator object.
    057   * <p/>
    058   * Since {@link TupleEntry} and the underlying {@link Tuple} instances are re-used, you must make a copy if you wish
    059   * to store the instances in a Collection for later use.
    060   *
    061   * @return the entry (type TupleEntry) of this TupleEntryIterator object.
    062   */
    063  public TupleEntry getTupleEntry()
    064    {
    065    return entry;
    066    }
    067  }