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.camel.impl;
018
019 import org.apache.camel.Exchange;
020 import org.apache.camel.Expression;
021 import org.apache.camel.Predicate;
022 import org.apache.camel.util.ObjectHelper;
023
024 /**
025 * A useful base class for {@link Predicate} and {@link Expression} implementations
026 *
027 * @version $Revision: 743330 $
028 */
029 public abstract class ExpressionSupport implements Expression, Predicate {
030
031 public boolean matches(Exchange exchange) {
032 Object value = evaluate(exchange);
033 return ObjectHelper.evaluateValuePredicate(value);
034 }
035
036 public <T> T evaluate(Exchange exchange, Class<T> type) {
037 Object result = evaluate(exchange);
038 return exchange.getContext().getTypeConverter().convertTo(type, result);
039 }
040
041 public void assertMatches(String text, Exchange exchange) {
042 if (!matches(exchange)) {
043 throw new AssertionError(text + " " + assertionFailureMessage(exchange) + " for exchange: " + exchange);
044 }
045 }
046
047 protected abstract String assertionFailureMessage(Exchange exchange);
048 }