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.Exchange;
020 import org.apache.camel.Expression;
021 import org.apache.camel.Processor;
022 import org.apache.commons.logging.Log;
023 import org.apache.commons.logging.LogFactory;
024
025 /**
026 * A processor which sets the header on the IN message
027 */
028 public class SetHeaderProcessor extends DelegateProcessor implements Processor {
029 private static final transient Log LOG = LogFactory.getLog(SetHeaderProcessor.class);
030 private String name;
031 private Expression expression;
032
033 public SetHeaderProcessor(String name, Expression expression) {
034 this.name = name;
035 this.expression = expression;
036 }
037
038 public SetHeaderProcessor(String name, Expression expression,
039 Processor childProcessor) {
040 super(childProcessor);
041 this.name = name;
042 this.expression = expression;
043 }
044
045 public void process(Exchange exchange) throws Exception {
046 Object value = expression.evaluate(exchange);
047 if (value == null) {
048 LOG.warn("Expression: " + expression
049 + " on exchange: " + exchange + " evaluated to null.");
050 }
051 exchange.getIn().setHeader(name, value);
052 super.process(exchange);
053 }
054
055 @Override
056 public String toString() {
057 return "setHeader(" + name + ", " + expression + ")";
058 }
059 }