001 /* 002 * Copyright (c) 2007-2014 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 */ 020 021 package cascading.tuple; 022 023 import java.io.Closeable; 024 import 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 */ 030 public 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 }