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;
018    
019    import org.apache.camel.util.ExchangeHelper;
020    
021    /**
022     * An exception caused when a mandatory header is not available on a message
023     * {@link Exchange}
024     *
025     * @see ExchangeHelper#getMandatoryHeader(Exchange, String, Class)
026     *
027     * @version $Revision: 633440 $
028     */
029    public class NoSuchHeaderException extends CamelExchangeException {
030        private static final long serialVersionUID = -8721487431101572630L;
031        private final String headerName;
032        private final Class<?> type;
033    
034        public NoSuchHeaderException(Exchange exchange, String headerName, Class<?> type) {
035            super("No '" + headerName + "' header available of type: " + type.getName()
036                  + reason(exchange, headerName), exchange);
037            this.headerName = headerName;
038            this.type = type;
039        }
040    
041        public String getHeaderName() {
042            return headerName;
043        }
044    
045        public Class<?> getType() {
046            return type;
047        }
048    
049        protected static String reason(Exchange exchange, String propertyName) {
050            Object value = exchange.getProperty(propertyName);
051            return valueDescription(value);
052        }
053    
054        static String valueDescription(Object value) {
055            if (value == null) {
056                return "";
057            }
058            return " but has value: " + value + " of type: " + value.getClass().getName();
059        }
060    }