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.processor; 018 019 import org.apache.camel.AsyncCallback; 020 import org.apache.camel.AsyncProcessor; 021 import org.apache.camel.Exchange; 022 import org.apache.camel.Expression; 023 import org.apache.camel.Message; 024 import org.apache.camel.Traceable; 025 import org.apache.camel.impl.DefaultMessage; 026 import org.apache.camel.support.ServiceSupport; 027 import org.apache.camel.util.AsyncProcessorHelper; 028 import org.apache.camel.util.ObjectHelper; 029 030 /** 031 * A processor which sets the body on the OUT message with an {@link Expression} 032 */ 033 public class TransformProcessor extends ServiceSupport implements AsyncProcessor, Traceable { 034 private final Expression expression; 035 036 public TransformProcessor(Expression expression) { 037 ObjectHelper.notNull(expression, "expression", this); 038 this.expression = expression; 039 } 040 041 public void process(Exchange exchange) throws Exception { 042 AsyncProcessorHelper.process(this, exchange); 043 } 044 045 public boolean process(Exchange exchange, AsyncCallback callback) { 046 try { 047 Object newBody = expression.evaluate(exchange, Object.class); 048 049 Message old = exchange.getIn(); 050 051 // create a new message container so we do not drag specialized message objects along 052 Message msg = new DefaultMessage(); 053 msg.copyFrom(old); 054 msg.setBody(newBody); 055 exchange.setOut(msg); 056 } catch (Exception e) { 057 exchange.setException(e); 058 } 059 060 callback.done(true); 061 return true; 062 } 063 064 @Override 065 public String toString() { 066 return "Transform(" + expression + ")"; 067 } 068 069 public String getTraceLabel() { 070 return "transform[" + expression + "]"; 071 } 072 073 @Override 074 protected void doStart() throws Exception { 075 // noop 076 } 077 078 @Override 079 protected void doStop() throws Exception { 080 // noop 081 } 082 }