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.ognl;
018
019 import java.util.HashMap;
020 import java.util.Map;
021
022 import ognl.Ognl;
023 import ognl.OgnlContext;
024 import ognl.OgnlException;
025
026 import org.apache.camel.Exchange;
027 import org.apache.camel.impl.ExpressionSupport;
028 import org.apache.camel.language.ExpressionEvaluationException;
029 import org.apache.camel.language.IllegalSyntaxException;
030
031 /**
032 * @version $Revision: $
033 */
034 public class OgnlExpression extends ExpressionSupport<Exchange> {
035
036 private final String expressionString;
037 private final Class<?> type;
038 private Object expression;
039
040 public OgnlExpression(OgnlLanguage language, String expressionString, Class<?> type) {
041 this.expressionString = expressionString;
042 this.type = type;
043 try {
044 this.expression = Ognl.parseExpression(expressionString);
045 } catch (OgnlException e) {
046 throw new IllegalSyntaxException(language, expressionString);
047 }
048 }
049
050 public static OgnlExpression ognl(String expression) {
051 return new OgnlExpression(new OgnlLanguage(), expression, Object.class);
052 }
053
054 public Object evaluate(Exchange exchange) {
055 // TODO we could use caching here but then we'd have possible
056 // concurrency issues
057 // so lets assume that the provider caches
058 Map values = new HashMap();
059 populateContext(values, exchange);
060 OgnlContext oglContext = new OgnlContext();
061 try {
062 return Ognl.getValue(expression, oglContext, new RootObject(exchange));
063 } catch (OgnlException e) {
064 throw new ExpressionEvaluationException(this, exchange, e);
065 }
066 }
067
068 protected void populateContext(Map map, Exchange exchange) {
069 map.put("exchange", exchange);
070 map.put("in", exchange.getIn());
071 map.put("out", exchange.getOut());
072 }
073
074 protected String assertionFailureMessage(Exchange exchange) {
075 return expressionString;
076 }
077 }