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
021 import org.apache.camel.spi.HeaderFilterStrategy;
022 import org.apache.camel.spi.UnitOfWork;
023
024 /**
025 * The base message exchange interface providing access to the request, response
026 * and fault {@link Message} instances. Different providers such as JMS, JBI,
027 * CXF and HTTP can provide their own derived API to expose the underlying
028 * transport semantics to avoid the leaky abstractions of generic APIs.
029 *
030 * @version $Revision: 943775 $
031 */
032 public interface Exchange {
033
034 String CHARSET_NAME = "org.apache.camel.Exchange.CharsetName";
035
036 String DEFAULT_CHARSET_PROPERTY = "org.apache.camel.default.charset";
037
038 String AGGREGATED_COUNT = "org.apache.camel.Exchange.AggregatedCount";
039
040 String EXCEPTION_HANDLED_PROPERTY = "CamelExceptionHandled";
041
042 /**
043 * Returns the {@link ExchangePattern} (MEP) of this exchange.
044 *
045 * @return the message exchange pattern of this exchange
046 */
047 ExchangePattern getPattern();
048
049 /**
050 * Allows the {@link ExchangePattern} (MEP) of this exchange to be customized.
051 *
052 * This typically won't be required as an exchange can be created with a specific MEP
053 * by calling {@link Endpoint#createExchange(ExchangePattern)} but it is here just in case
054 * it is needed.
055 *
056 * @param pattern the pattern
057 */
058 void setPattern(ExchangePattern pattern);
059
060 /**
061 * Returns a property associated with this exchange by name
062 *
063 * @param name the name of the property
064 * @return the value of the given header or null if there is no property for
065 * the given name
066 */
067 Object getProperty(String name);
068
069 /**
070 * Returns a property associated with this exchange by name and specifying
071 * the type required
072 *
073 * @param name the name of the property
074 * @param type the type of the property
075 * @return the value of the given header or null if there is no property for
076 * the given name or null if it cannot be converted to the given type
077 */
078 <T> T getProperty(String name, Class<T> type);
079
080 /**
081 * Sets a property on the exchange
082 *
083 * @param name of the property
084 * @param value to associate with the name
085 */
086 void setProperty(String name, Object value);
087
088 /**
089 * Removes the given property on the exchange
090 *
091 * @param name of the property
092 * @return the old value of the property
093 */
094 Object removeProperty(String name);
095
096 /**
097 * Returns all of the properties associated with the exchange
098 *
099 * @return all the headers in a Map
100 */
101 Map<String, Object> getProperties();
102
103 /**
104 * Returns the inbound request message
105 *
106 * @return the message
107 */
108 Message getIn();
109
110 /**
111 * Sets the inbound message instance
112 *
113 * @param in the inbound message
114 */
115 void setIn(Message in);
116
117 /**
118 * Returns the outbound message, lazily creating one if one has not already
119 * been associated with this exchange. If you want to check if this exchange
120 * has an out, but not force lazy creation, invoke {@link #hasOut()} first
121 * Starting with Camel 2.0.0 an out message could also represent a fault,
122 * i.e. a persistent error at the application level (equivalent to faults
123 * defines in some specifications like wsdl and jbi). You should use
124 * {@link #org.apache.camel.Message}} fault apis to get/set the fault
125 * flag for the out message.
126 *
127 * @return the response
128 */
129 Message getOut();
130
131 /**
132 * Returns the outbound message; optionally lazily creating one if one has
133 * not been associated with this exchange
134 *
135 * @deprecated Starting with Camel 2.0.0 you should only use {@link #getOut()}
136 * @param lazyCreate <tt>true</tt> will lazy create the out message
137 * @return the response
138 */
139 Message getOut(boolean lazyCreate);
140
141 /**
142 * Sets the outbound message
143 *
144 * @param out the outbound message
145 */
146 void setOut(Message out);
147
148 /**
149 * Returns the fault message
150 *
151 * @deprecated Starting with Camel 2.0.0 you should use {@link #getOut()}
152 * and check the {@link #org.apache.camel.Message.isFault()} flag
153 * @return the fault
154 */
155 Message getFault();
156
157 /**
158 * Returns the fault message; optionally lazily creating one if one has
159 * not been associated with this exchange
160 *
161 * @deprecated Starting with Camel 2.0.0 you should use {@link #getOut()}
162 * and check the {@link #org.apache.camel.Message.isFault()} flag
163 * @param lazyCreate <tt>true</tt> will lazy create the fault message
164 * @return the fault
165 */
166 Message getFault(boolean lazyCreate);
167
168 /**
169 * Returns the exception associated with this exchange
170 *
171 * @return the exception (or null if no faults)
172 */
173 Throwable getException();
174
175 /**
176 * Sets the exception associated with this exchange
177 *
178 * @param e the caused exception
179 */
180 void setException(Throwable e);
181
182 /**
183 * Returns true if this exchange failed due to either an exception or fault
184 *
185 * @return true if this exchange failed due to either an exception or fault
186 * @see Exchange#getException()
187 * @see Exchange#getOut()
188 */
189 boolean isFailed();
190
191 /**
192 * Returns true if this exchange is transacted
193 */
194 boolean isTransacted();
195
196 /**
197 * Returns the container so that a processor can resolve endpoints from URIs
198 *
199 * @return the container which owns this exchange
200 */
201 CamelContext getContext();
202
203 /**
204 * Creates a new exchange instance with empty messages, headers and properties
205 *
206 * @deprecated Starting with Camel 2.0.0 you should use {@link #copy()}
207 * to get a new instance of an exchange or simply create a new
208 * exchange object
209 */
210 Exchange newInstance();
211
212 /**
213 * Creates a copy of the current message exchange so that it can be
214 * forwarded to another destination
215 */
216 Exchange copy();
217
218 /**
219 * Copies the data into this exchange from the given exchange
220 *
221 * @deprecated Starting with Camel 2.0.0 you should use {@link #copy()}
222 * to get a new instance of an exchange or simply create a new
223 * exchange object
224 * @param source is the source from which headers and messages will be copied
225 */
226 void copyFrom(Exchange source);
227
228 /**
229 * Returns the unit of work that this exchange belongs to; which may map to
230 * zero, one or more physical transactions
231 */
232 UnitOfWork getUnitOfWork();
233
234 /**
235 * Sets the unit of work that this exchange belongs to; which may map to
236 * zero, one or more physical transactions
237 */
238 void setUnitOfWork(UnitOfWork unitOfWork);
239
240 /**
241 * Returns the exchange id (unique)
242 */
243 String getExchangeId();
244
245 /**
246 * Set the exchange id
247 */
248 void setExchangeId(String id);
249 }