| /** |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.activemq.store.amq.reader; |
| |
| import java.util.Iterator; |
| |
| import javax.jms.Message; |
| import org.apache.activemq.broker.region.MessageReference; |
| import org.apache.activemq.filter.BooleanExpression; |
| import org.apache.activemq.filter.MessageEvaluationContext; |
| |
| /** |
| * An Iterator for the AMQReader |
| * |
| */ |
| class AMQIterator implements Iterator<Message>{ |
| private AMQReader reader; |
| private BooleanExpression expression; |
| private MessageLocation currentLocation; |
| private MessageLocation nextLocation; |
| private boolean valid=true; |
| |
| |
| AMQIterator(AMQReader reader, BooleanExpression expression){ |
| this.reader=reader; |
| this.expression=expression; |
| } |
| |
| public boolean hasNext() { |
| try { |
| this.nextLocation = reader.getNextMessage(currentLocation); |
| Message next = nextLocation != null ? nextLocation.getMessage() |
| : null; |
| if (expression == null) { |
| return next != null; |
| } else { |
| while (next != null) { |
| MessageEvaluationContext context = new MessageEvaluationContext(); |
| context.setMessageReference((MessageReference) next); |
| if (expression.matches(context)) { |
| return true; |
| } |
| this.nextLocation = reader.getNextMessage(currentLocation); |
| next = nextLocation != null ? nextLocation.getMessage() |
| : null; |
| } |
| valid=false; |
| return false; |
| } |
| } catch (Exception e) { |
| throw new RuntimeException( |
| "Failed to get next message from reader ", e); |
| } |
| } |
| |
| |
| public Message next() { |
| if (valid && (nextLocation != null || hasNext())) { |
| this.currentLocation=nextLocation; |
| return nextLocation.getMessage(); |
| } |
| return null; |
| } |
| |
| |
| public void remove() { |
| throw new IllegalStateException("Not supported"); |
| |
| } |
| |
| } |