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 import java.util.Set;
022
023 import javax.activation.DataHandler;
024
025 import org.apache.camel.Exchange;
026
027 /**
028 * The default implementation of {@link org.apache.camel.Message}
029 *
030 * @version $Revision: 751221 $
031 */
032 public class DefaultMessage extends MessageSupport {
033 private Map<String, Object> headers;
034 private Map<String, DataHandler> attachments;
035
036 @Override
037 public String toString() {
038 return "Message: " + getBody();
039 }
040
041 public Object getHeader(String name) {
042 return getHeaders().get(name);
043 }
044
045 public <T> T getHeader(String name, Class<T> type) {
046 Object value = getHeader(name);
047 Exchange e = getExchange();
048 return e.getContext().getTypeConverter().convertTo(type, e, value);
049 }
050
051 public void setHeader(String name, Object value) {
052 if (headers == null) {
053 headers = createHeaders();
054 }
055 headers.put(name, value);
056 }
057
058 public Object removeHeader(String name) {
059 if (headers != null) {
060 return headers.remove(name);
061 } else {
062 return null;
063 }
064 }
065
066 public Map<String, Object> getHeaders() {
067 if (headers == null) {
068 headers = createHeaders();
069 }
070 return headers;
071 }
072
073 public void setHeaders(Map<String, Object> headers) {
074 this.headers = headers;
075 }
076
077 public DefaultMessage newInstance() {
078 return new DefaultMessage();
079 }
080
081 /**
082 * A factory method to lazily create the headers to make it easy to create
083 * efficient Message implementations which only construct and populate the
084 * Map on demand
085 *
086 * @return return a newly constructed Map possibly containing headers from
087 * the underlying inbound transport
088 */
089 protected Map<String, Object> createHeaders() {
090 Map<String, Object> map = new HashMap<String, Object>();
091 populateInitialHeaders(map);
092 return map;
093 }
094
095 /**
096 * A strategy method populate the initial set of headers on an inbound
097 * message from an underlying binding
098 *
099 * @param map is the empty header map to populate
100 */
101 protected void populateInitialHeaders(Map<String, Object> map) {
102 }
103
104 /**
105 * A factory method to lazily create the attachments to make it easy to
106 * create efficient Message implementations which only construct and
107 * populate the Map on demand
108 *
109 * @return return a newly constructed Map
110 */
111 protected Map<String, DataHandler> createAttachments() {
112 Map<String, DataHandler> map = new HashMap<String, DataHandler>();
113 populateInitialAttachments(map);
114 return map;
115 }
116
117 /**
118 * A strategy method populate the initial set of attachments on an inbound
119 * message from an underlying binding
120 *
121 * @param map is the empty attachment map to populate
122 */
123 protected void populateInitialAttachments(Map<String, DataHandler> map) {
124 }
125
126 public void addAttachment(String id, DataHandler content) {
127 if (attachments == null) {
128 attachments = createAttachments();
129 }
130 attachments.put(id, content);
131 }
132
133 public DataHandler getAttachment(String id) {
134 return getAttachments().get(id);
135 }
136
137 public Set<String> getAttachmentNames() {
138 if (attachments == null) {
139 attachments = createAttachments();
140 }
141 return attachments.keySet();
142 }
143
144 public void removeAttachment(String id) {
145 if (attachments != null && attachments.containsKey(id)) {
146 attachments.remove(id);
147 }
148 }
149
150 public Map<String, DataHandler> getAttachments() {
151 if (attachments == null) {
152 attachments = createAttachments();
153 }
154 return attachments;
155 }
156
157 public void setAttachments(Map<String, DataHandler> attachments) {
158 this.attachments = attachments;
159 }
160
161 public boolean hasAttachments() {
162 if (attachments == null) {
163 attachments = createAttachments();
164 }
165 return this.attachments != null && this.attachments.size() > 0;
166 }
167
168 /**
169 * Returns true if the headers have been mutated in some way
170 */
171 protected boolean hasPopulatedHeaders() {
172 return headers != null;
173 }
174
175 public String createExchangeId() {
176 return null;
177 }
178 }