001    /*
002      GRANITE DATA SERVICES
003      Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004    
005      This file is part of Granite Data Services.
006    
007      Granite Data Services is free software; you can redistribute it and/or modify
008      it under the terms of the GNU Library General Public License as published by
009      the Free Software Foundation; either version 2 of the License, or (at your
010      option) any later version.
011    
012      Granite Data Services is distributed in the hope that it will be useful, but
013      WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014      FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015      for more details.
016    
017      You should have received a copy of the GNU Library General Public License
018      along with this library; if not, see <http://www.gnu.org/licenses/>.
019    */
020    
021    package org.granite.gravity.selector;
022    
023    import java.io.IOException;
024    
025    import javax.jms.JMSException;
026    
027    import org.apache.activemq.command.Response;
028    import org.apache.activemq.filter.BooleanExpression;
029    import org.apache.activemq.filter.MessageEvaluationContext;
030    import org.apache.activemq.selector.SelectorParser;
031    import org.apache.activemq.state.CommandVisitor;
032    
033    import flex.messaging.messages.Message;
034    
035    /**
036     * @author William DRAI
037     */
038    public class ActiveMQMessageSelector implements MessageSelector {
039    
040        private BooleanExpression expression;
041    
042    
043        public ActiveMQMessageSelector(String selector) {
044            try {
045                this.expression = SelectorParser.parse(selector);
046            }
047            catch (Exception e) {
048                throw new RuntimeException("ActiveMQ SelectorParser error " + selector, e);
049            }
050        }
051    
052        public boolean accept(Message message) {
053            try {
054                MessageEvaluationContext context = new MessageEvaluationContext();
055                MessageAdapter ma = new MessageAdapter(message);
056                context.setMessageReference(ma);
057    
058                return expression.matches(context);
059            }
060            catch (Exception e) {
061                throw new RuntimeException("ActiveMQ selector accept error " + message, e);
062            }
063        }
064    
065    
066        private static class MessageAdapter extends org.apache.activemq.command.Message {
067            private Message message = null;
068    
069            public MessageAdapter(Message message) {
070                this.message = message;
071            }
072    
073            @Override
074            public Object getProperty(String name) throws IOException {
075                return message.getHeader(name);
076            }
077    
078            @Override
079            public org.apache.activemq.command.Message copy() {
080                return null;
081            }
082    
083            public Response visit(CommandVisitor visitor) throws Exception {
084                return null;
085            }
086    
087            public byte getDataStructureType() {
088                return 0;
089            }
090    
091                    @Override
092                    public void clearBody() throws JMSException {
093                    }
094        }
095    }