001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.activemq.kaha.impl.container; 018 019 import java.util.Iterator; 020 import org.apache.activemq.kaha.impl.index.IndexItem; 021 import org.apache.activemq.kaha.impl.index.IndexLinkedList; 022 023 /** 024 * Iterator for the set of keys for a container 025 * 026 * 027 */ 028 public class ContainerKeySetIterator implements Iterator { 029 030 protected IndexItem nextItem; 031 protected IndexItem currentItem; 032 033 private MapContainerImpl container; 034 private IndexLinkedList list; 035 036 ContainerKeySetIterator(MapContainerImpl container) { 037 this.container = container; 038 this.list = container.getInternalList(); 039 this.currentItem = list.getRoot(); 040 this.nextItem = list.getNextEntry(currentItem); 041 } 042 043 public boolean hasNext() { 044 return nextItem != null; 045 } 046 047 public Object next() { 048 currentItem = nextItem; 049 Object result = container.getKey(nextItem); 050 nextItem = list.getNextEntry(nextItem); 051 return result; 052 } 053 054 public void remove() { 055 if (currentItem != null) { 056 container.remove(currentItem); 057 if (nextItem != null) { 058 list.refreshEntry(nextItem); 059 } 060 } 061 } 062 }