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 * <p/>
029 * See {@link org.apache.camel.impl.DefaultMessage DefaultMessage} for how headers is represented in Camel using a
030 * {@link org.apache.camel.util.CaseInsensitiveMap CaseInsensitiveMap}.
031 *
032 * @version $Revision: 802994 $
033 */
034 public interface Message {
035
036 /**
037 * Returns the id of the message
038 *
039 * @return the message id
040 */
041 String getMessageId();
042
043 /**
044 * Sets the id of the message
045 *
046 * @param messageId id of the message
047 */
048 void setMessageId(String messageId);
049
050 /**
051 * Returns the exchange this message is related to
052 *
053 * @return the exchange
054 */
055 Exchange getExchange();
056
057 /**
058 * Returns true if this message represents a fault
059 *
060 * @return <tt>true</tt> if this is a fault message, <tt>false</tt> for regular messages.
061 */
062 boolean isFault();
063
064 /**
065 * Sets the fault flag on this message
066 *
067 * @param fault the fault flag
068 */
069 void setFault(boolean fault);
070
071 /**
072 * Accesses a specific header
073 *
074 * @param name name of header
075 * @return object header associated with the name
076 */
077 Object getHeader(String name);
078
079 /**
080 * Returns a header associated with this message by name and specifying the
081 * type required
082 *
083 * @param name the name of the header
084 * @param type the type of the header
085 * @return the value of the given header or null if there is no property for
086 * the given name or it cannot be converted to the given type
087 */
088 <T> T getHeader(String name, Class<T> type);
089
090 /**
091 * Sets a header on the message
092 *
093 * @param name of the header
094 * @param value to associate with the name
095 */
096 void setHeader(String name, Object value);
097
098 /**
099 * Removes the named header from this message
100 *
101 * @param name name of the header
102 * @return the old value of the header
103 */
104 Object removeHeader(String name);
105
106 /**
107 * Returns all of the headers associated with the message
108 *
109 * @return all the headers in a Map
110 */
111 Map<String, Object> getHeaders();
112
113 /**
114 * Set all the headers associated with this message
115 *
116 * @param headers headers to set
117 */
118 void setHeaders(Map<String, Object> headers);
119
120 /**
121 * Returns whether has any headers has been set.
122 *
123 * @return <tt>true</tt> if any headers has been set
124 */
125 boolean hasHeaders();
126
127 /**
128 * Returns the body of the message as a POJO
129 * <p/>
130 * The body can be <tt>null</tt> if no body is set
131 *
132 * @return the body, can be <tt>null</tt>
133 */
134 Object getBody();
135
136 /**
137 * Returns the body of the message as a POJO
138 *
139 * @return the body, is never <tt>null</tt>
140 * @throws InvalidPayloadException Is thrown if the body being <tt>null</tt> or wrong class type
141 */
142 Object getMandatoryBody() throws InvalidPayloadException;
143
144 /**
145 * Returns the body as the specified type
146 *
147 * @param type the type that the body
148 * @return the body of the message as the specified type, or <tt>null</tt> if not possible to convert
149 */
150 <T> T getBody(Class<T> type);
151
152 /**
153 * Returns the mandatory body as the specified type
154 *
155 * @param type the type that the body
156 * @return the body of the message as the specified type, is never <tt>null</tt>.
157 * @throws InvalidPayloadException Is thrown if the body being <tt>null</tt> or wrong class type
158 */
159 <T> T getMandatoryBody(Class<T> type) throws InvalidPayloadException;
160
161 /**
162 * Sets the body of the message
163 *
164 * @param body the body
165 */
166 void setBody(Object body);
167
168 /**
169 * Sets the body of the message as a specific type
170 *
171 * @param body the body
172 * @param type the type of the body
173 */
174 <T> void setBody(Object body, Class<T> type);
175
176 /**
177 * Creates a copy of this message so that it can be used and possibly
178 * modified further in another exchange
179 *
180 * @return a new message instance copied from this message
181 */
182 Message copy();
183
184 /**
185 * Copies the contents of the other message into this message
186 *
187 * @param message the other message
188 */
189 void copyFrom(Message message);
190
191 /**
192 * Returns the attachment specified by the id
193 *
194 * @param id the id under which the attachment is stored
195 * @return the data handler for this attachment or null
196 */
197 DataHandler getAttachment(String id);
198
199 /**
200 * Returns a set of attachment names of the message
201 *
202 * @return a set of attachment names
203 */
204 Set<String> getAttachmentNames();
205
206 /**
207 * Removes the attachment specified by the id
208 *
209 * @param id the id of the attachment to remove
210 */
211 void removeAttachment(String id);
212
213 /**
214 * Adds an attachment to the message using the id
215 *
216 * @param id the id to store the attachment under
217 * @param content the data handler for the attachment
218 */
219 void addAttachment(String id, DataHandler content);
220
221 /**
222 * Returns all attachments of the message
223 *
224 * @return the attachments in a map or null
225 */
226 Map<String, DataHandler> getAttachments();
227
228 /**
229 * Set all the attachments associated with this message
230 *
231 * @param attachments attachements
232 */
233 void setAttachments(Map<String, DataHandler> attachments);
234
235 /**
236 * Returns whether this message has attachments.
237 *
238 * @return <tt>true</tt> if this message has any attachments.
239 */
240 boolean hasAttachments();
241
242 /**
243 * Returns the unique ID for a message exchange if this message is capable of creating one or null if not
244 *
245 * @return the created exchange id, or <tt>null</tt> if not capable of creating
246 */
247 String createExchangeId();
248 }