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 }