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.filter;
018    
019    import javax.jms.JMSException;
020    
021    /**
022     * Used to evaluate an XQuery Expression in a JMS selector.
023     */
024    public final class XQueryExpression implements BooleanExpression {
025        private final String xpath;
026    
027        XQueryExpression(String xpath) {
028            super();
029            this.xpath = xpath;
030        }
031    
032        public Object evaluate(MessageEvaluationContext message) throws JMSException {
033            return Boolean.FALSE;
034        }
035    
036        public String toString() {
037            return "XQUERY " + ConstantExpression.encodeString(xpath);
038        }
039    
040        /**
041         * @param message
042         * @return true if the expression evaluates to Boolean.TRUE.
043         * @throws JMSException
044         */
045        public boolean matches(MessageEvaluationContext message) throws JMSException {
046            Object object = evaluate(message);
047            return object != null && object == Boolean.TRUE;
048        }
049    
050    }