001/* 002 * Copyright (c) 2016-2017 Chris K Wensel <chris@wensel.net>. All Rights Reserved. 003 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved. 004 * 005 * Project and contact information: http://www.cascading.org/ 006 * 007 * This file is part of the Cascading project. 008 * 009 * Licensed under the Apache License, Version 2.0 (the "License"); 010 * you may not use this file except in compliance with the License. 011 * You may obtain a copy of the License at 012 * 013 * http://www.apache.org/licenses/LICENSE-2.0 014 * 015 * Unless required by applicable law or agreed to in writing, software 016 * distributed under the License is distributed on an "AS IS" BASIS, 017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 018 * See the License for the specific language governing permissions and 019 * limitations under the License. 020 */ 021 022package cascading.tuple; 023 024import java.io.Closeable; 025import java.util.Iterator; 026 027/** 028 * Class TupleEntryIterator provides an efficient Iterator for returning {@link TupleEntry} elements in an 029 * underlying {@link Tuple} collection. 030 */ 031public abstract class TupleEntryIterator implements Iterator<TupleEntry>, Closeable 032 { 033 /** Field entry */ 034 final TupleEntry entry; 035 036 /** 037 * Constructor TupleEntryIterator creates a new TupleEntryIterator instance. 038 * 039 * @param fields of type Fields 040 */ 041 public TupleEntryIterator( Fields fields ) 042 { 043 this.entry = new TupleEntry( fields, Tuple.size( fields.size() ) ); 044 } 045 046 /** 047 * Method getFields returns the fields of this TupleEntryIterator object. 048 * 049 * @return the fields (type Fields) of this TupleEntryIterator object. 050 */ 051 public Fields getFields() 052 { 053 return entry.getFields(); 054 } 055 056 /** 057 * Method getTupleEntry returns the entry of this TupleEntryIterator object. 058 * <p> 059 * Since {@link TupleEntry} and the underlying {@link Tuple} instances are re-used, you must make a copy if you wish 060 * to store the instances in a Collection for later use. 061 * 062 * @return the entry (type TupleEntry) of this TupleEntryIterator object. 063 */ 064 public TupleEntry getTupleEntry() 065 { 066 return entry; 067 } 068 }