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 */
017package org.apache.camel;
018
019/**
020 * Evaluates a binary <a
021 * href="http://camel.apache.org/predicate.html">predicate</a> on the
022 * message exchange to support things like <a
023 * href="http://camel.apache.org/scripting-languages.html">scripting
024 * languages</a>, <a href="http://camel.apache.org/xquery.html">XQuery</a>
025 * or <a href="http://camel.apache.org/sql.html">SQL</a> as well as
026 * any arbitrary Java expression.
027 */
028public interface Predicate {
029
030    /**
031     * Evaluates the predicate on the message exchange and returns true if this
032     * exchange matches the predicate
033     * 
034     * @param exchange the message exchange
035     * @return true if the predicate matches
036     */
037    boolean matches(Exchange exchange);
038
039}