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.language.bean;
018
019 import org.apache.camel.Exchange;
020 import org.apache.camel.ExchangePattern;
021 import org.apache.camel.component.bean.BeanHolder;
022 import org.apache.camel.component.bean.BeanProcessor;
023 import org.apache.camel.component.bean.ConstantBeanHolder;
024 import org.apache.camel.component.bean.RegistryBean;
025 import org.apache.camel.impl.ExpressionSupport;
026
027 /**
028 * Evaluates an expression using a bean method invocation
029 *
030 * @version $Revision: 688350 $
031 */
032 public class BeanExpression<E extends Exchange> extends ExpressionSupport<E> {
033 private String beanName;
034 private String method;
035 private Object bean;
036
037 public BeanExpression(Object bean, String method) {
038 this.bean = bean;
039 this.method = method;
040 }
041
042 public BeanExpression(String beanName, String method) {
043 this.beanName = beanName;
044 this.method = method;
045 }
046
047 @Override
048 public String toString() {
049 return "BeanExpression[bean:" + (bean == null ? beanName : bean) + " method: " + method + "]";
050 }
051
052 protected String assertionFailureMessage(E exchange) {
053 return "bean: " + beanName + " method: " + method;
054 }
055
056 public Object evaluate(E exchange) {
057 // either use registry lookup or a constant bean
058 BeanHolder holder;
059 if (bean == null) {
060 holder = new RegistryBean(exchange.getContext(), beanName);
061 } else {
062 holder = new ConstantBeanHolder(bean, exchange.getContext());
063 }
064
065 BeanProcessor processor = new BeanProcessor(holder);
066 if (method != null) {
067 processor.setMethod(method);
068 }
069 try {
070 Exchange newExchange = exchange.copy();
071 // The BeanExperession always has a result regardless of the ExchangePattern,
072 // so I add a checker here to make sure we can get the result.
073 if (!newExchange.getPattern().isOutCapable()) {
074 newExchange.setPattern(ExchangePattern.InOut);
075 }
076 processor.process(newExchange);
077 return newExchange.getOut(true).getBody();
078 } catch (Exception e) {
079 throw new RuntimeBeanExpressionException(exchange, beanName, method, e);
080 }
081 }
082 }