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.impl;
018
019 import java.util.HashMap;
020 import java.util.Map;
021
022 /**
023 * The default implementation of {@link Message}
024 *
025 * @version $Revision: 563607 $
026 */
027 public class DefaultMessage extends MessageSupport {
028 private Map<String, Object> headers;
029
030 @Override
031 public String toString() {
032 return "Message: " + getBody();
033 }
034
035 public Object getHeader(String name) {
036 return getHeaders().get(name);
037 }
038
039 public <T> T getHeader(String name, Class<T> type) {
040 Object value = getHeader(name);
041 return getExchange().getContext().getTypeConverter().convertTo(type, value);
042 }
043
044 public void setHeader(String name, Object value) {
045 if (headers == null) {
046 headers = createHeaders();
047 }
048 headers.put(name, value);
049 }
050
051 public Map<String, Object> getHeaders() {
052 if (headers == null) {
053 headers = createHeaders();
054 }
055 return headers;
056 }
057
058 public void setHeaders(Map<String, Object> headers) {
059 this.headers = headers;
060 }
061
062 public DefaultMessage newInstance() {
063 return new DefaultMessage();
064 }
065
066 /**
067 * A factory method to lazily create the headers to make it easy to create
068 * efficient Message implementations which only construct and populate the
069 * Map on demand
070 *
071 * @return return a newly constructed Map possibly containing headers from
072 * the underlying inbound transport
073 */
074 protected Map<String, Object> createHeaders() {
075 HashMap<String, Object> map = new HashMap<String, Object>();
076 populateInitialHeaders(map);
077 return map;
078 }
079
080 /**
081 * A strategy method populate the initial set of headers on an inbound
082 * 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 }