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.processor; 018 019import org.apache.camel.AsyncCallback; 020import org.apache.camel.AsyncProcessor; 021import org.apache.camel.Exchange; 022import org.apache.camel.Expression; 023import org.apache.camel.Traceable; 024import org.apache.camel.util.AsyncProcessorHelper; 025 026/** 027 * A {@link org.apache.camel.Processor} which evaluates an {@link Expression} 028 * and stores the result as a property on the {@link Exchange} with the key 029 * {@link Exchange#EVALUATE_EXPRESSION_RESULT}. 030 * <p/> 031 * This processor will in case of evaluation exceptions, set the caused exception 032 * on the {@link Exchange}. 033 */ 034public class EvaluateExpressionProcessor implements AsyncProcessor, Traceable { 035 036 private final Expression expression; 037 038 public EvaluateExpressionProcessor(Expression expression) { 039 this.expression = expression; 040 } 041 042 @Override 043 public void process(Exchange exchange) throws Exception { 044 AsyncProcessorHelper.process(this, exchange); 045 } 046 047 @Override 048 public boolean process(Exchange exchange, AsyncCallback callback) { 049 try { 050 Object result = expression.evaluate(exchange, Object.class); 051 exchange.setProperty(Exchange.EVALUATE_EXPRESSION_RESULT, result); 052 } catch (Throwable e) { 053 exchange.setException(e); 054 } finally { 055 callback.done(true); 056 } 057 return true; 058 } 059 060 @Override 061 public String toString() { 062 return "EvalExpression[" + expression + "]"; 063 } 064 065 public String getTraceLabel() { 066 return "eval[" + expression + "]"; 067 } 068 069}