001 /**
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one or more
004 * contributor license agreements. See the NOTICE file distributed with
005 * this work for additional information regarding copyright ownership.
006 * The ASF licenses this file to You under the Apache License, Version 2.0
007 * (the "License"); you may not use this file except in compliance with
008 * the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 package org.apache.camel.impl;
019
020 import org.apache.camel.Message;
021
022 import java.util.HashMap;
023 import java.util.Map;
024
025 /**
026 * The default implementation of {@link Message}
027 *
028 * @version $Revision: 540969 $
029 */
030 public class DefaultMessage extends MessageSupport {
031 private Map<String, Object> headers;
032
033 @Override
034 public String toString() {
035 return "Message: " + getBody();
036 }
037
038 public Object getHeader(String name) {
039 return getHeaders().get(name);
040 }
041
042 public <T> T getHeader(String name, Class<T> type) {
043 Object value = getHeader(name);
044 return getExchange().getContext().getTypeConverter().convertTo(type, value);
045 }
046
047 public void setHeader(String name, Object value) {
048 if (headers == null) {
049 headers = createHeaders();
050 }
051 headers.put(name, value);
052 }
053
054 public Map<String, Object> getHeaders() {
055 if (headers == null) {
056 headers = createHeaders();
057 }
058 return headers;
059 }
060
061 public void setHeaders(Map<String, Object> headers) {
062 this.headers = headers;
063 }
064
065 public DefaultMessage newInstance() {
066 return new DefaultMessage();
067 }
068
069 /**
070 * A factory method to lazily create the headers to make it easy to create efficient Message implementations
071 * which only construct and populate the Map on demand
072 *
073 * @return return a newly constructed Map possibly containing headers from the underlying inbound transport
074 */
075 protected Map<String, Object> createHeaders() {
076 HashMap<String, Object> map = new HashMap<String, Object>();
077 populateInitialHeaders(map);
078 return map;
079 }
080
081 /**
082 * A strategy method populate the initial set of headers on an inbound message from an underlying binding
083 *
084 * @param map is the empty header map to populate
085 */
086 protected void populateInitialHeaders(Map<String, Object> map) {
087 }
088 }