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 java.util.Map;
020 import java.util.Set;
021
022 import javax.activation.DataHandler;
023
024 /**
025 * Implements the <a
026 * href="http://camel.apache.org/message.html">Message</a> pattern and
027 * represents an inbound or outbound message as part of an {@link Exchange}
028 *
029 * @version $Revision: 755890 $
030 */
031 public interface Message {
032
033 /**
034 * Returns the id of the message
035 */
036 String getMessageId();
037
038 /**
039 * Sets the id of the message
040 *
041 * @param messageId id of the message
042 */
043 void setMessageId(String messageId);
044
045 /**
046 * Returns the exchange this message is related to
047 */
048 Exchange getExchange();
049
050 /**
051 * Accesses a specific header
052 *
053 * @param name name of header
054 * @return object header associated with the name
055 */
056 Object getHeader(String name);
057
058 /**
059 * Returns a header associated with this message by name and specifying the
060 * type required
061 *
062 * @param name the name of the header
063 * @param type the type of the header
064 * @return the value of the given header or null if there is no property for
065 * the given name or it cannot be converted to the given type
066 */
067 <T> T getHeader(String name, Class<T> type);
068
069 /**
070 * Sets a header on the message
071 *
072 * @param name of the header
073 * @param value to associate with the name
074 */
075 void setHeader(String name, Object value);
076
077 /**
078 * Removes the named header from this message
079 *
080 * @param name name of the header
081 * @return the old value of the header
082 */
083 Object removeHeader(String name);
084
085 /**
086 * Returns all of the headers associated with the message
087 *
088 * @return all the headers in a Map
089 */
090 Map<String, Object> getHeaders();
091
092 /**
093 * Set all the headers associated with this message
094 *
095 * @param headers headers to set
096 */
097 void setHeaders(Map<String, Object> headers);
098
099 /**
100 * Returns the body of the message as a POJO
101 * <p/>
102 * The body can be <tt>null</tt> if no body is set
103 *
104 * @return the body, can be <tt>null</tt>
105 */
106 Object getBody();
107
108 /**
109 * Returns the body of the message as a POJO
110 *
111 * @return the body, is never <tt>null</tt>
112 * @throws InvalidPayloadException Is thrown if the body being <tt>null</tt> or wrong class type
113 */
114 Object getMandatoryBody() throws InvalidPayloadException;
115
116 /**
117 * Returns the body as the specified type
118 *
119 * @param type the type that the body
120 * @return the body of the message as the specified type, or <tt>null</tt> if not possible to convert
121 */
122 <T> T getBody(Class<T> type);
123
124 /**
125 * Returns the mandatory body as the specified type
126 *
127 * @param type the type that the body
128 * @return the body of the message as the specified type, is never <tt>null</tt>.
129 * @throws InvalidPayloadException Is thrown if the body being <tt>null</tt> or wrong class type
130 */
131 <T> T getMandatoryBody(Class<T> type) throws InvalidPayloadException;
132
133 /**
134 * Sets the body of the message
135 *
136 * @param body the body
137 */
138 void setBody(Object body);
139
140 /**
141 * Sets the body of the message as a specific type
142 *
143 * @param body the body
144 * @param type the type of the body
145 */
146 <T> void setBody(Object body, Class<T> type);
147
148 /**
149 * Creates a copy of this message so that it can be used and possibly
150 * modified further in another exchange
151 *
152 * @return a new message instance copied from this message
153 */
154 Message copy();
155
156 /**
157 * Copies the contents of the other message into this message
158 *
159 * @param message the other message
160 */
161 void copyFrom(Message message);
162
163 /**
164 * Returns the attachment specified by the id
165 *
166 * @param id the id under which the attachment is stored
167 * @return the data handler for this attachment or null
168 */
169 DataHandler getAttachment(String id);
170
171 /**
172 * Returns a set of attachment names of the message
173 *
174 * @return a set of attachment names
175 */
176 Set<String> getAttachmentNames();
177
178 /**
179 * Removes the attachment specified by the id
180 *
181 * @param id the id of the attachment to remove
182 */
183 void removeAttachment(String id);
184
185 /**
186 * Adds an attachment to the message using the id
187 *
188 * @param id the id to store the attachment under
189 * @param content the data handler for the attachment
190 */
191 void addAttachment(String id, DataHandler content);
192
193 /**
194 * Returns all attachments of the message
195 *
196 * @return the attachments in a map or null
197 */
198 Map<String, DataHandler> getAttachments();
199
200 /**
201 * Set all the attachments associated with this message
202 *
203 * @param attachments attachements
204 */
205 void setAttachments(Map<String, DataHandler> attachments);
206
207 /**
208 * Returns <tt>true</tt> if this message has any attachments.
209 */
210 boolean hasAttachments();
211
212 /**
213 * Returns the unique ID for a message exchange if this message is capable of creating one or null if not
214 */
215 String createExchangeId();
216 }