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.UnitOfWork;
022
023 /**
024 * The base message exchange interface providing access to the request, response
025 * and fault {@link Message} instances. Different providers such as JMS, JBI,
026 * CXF and HTTP can provide their own derived API to expose the underlying
027 * transport semantics to avoid the leaky abstractions of generic APIs.
028 *
029 * @version $Revision: 52965 $
030 */
031 public interface Exchange {
032
033 String CHARSET_NAME = "org.apache.camel.Exchange.CharsetName";
034
035 String AGGREGATED_COUNT = "org.apache.camel.Exchange.AggregatedCount";
036
037 /**
038 * Returns the {@link ExchangePattern} (MEP) of this exchange.
039 *
040 * @return the message exchange pattern of this exchange
041 */
042 ExchangePattern getPattern();
043
044 /**
045 * Allows the {@link ExchangePattern} (MEP) of this exchange to be customized.
046 *
047 * This typically won't be required as an exchange can be created with a specific MEP
048 * by calling {@link Endpoint#createExchange(ExchangePattern)} but it is here just in case
049 * it is needed.
050 *
051 * @param pattern the pattern
052 */
053 void setPattern(ExchangePattern pattern);
054
055 /**
056 * Returns a property associated with this exchange by name
057 *
058 * @param name the name of the property
059 * @return the value of the given header or null if there is no property for
060 * the given name
061 */
062 Object getProperty(String name);
063
064 /**
065 * Returns a property associated with this exchange by name and specifying
066 * the type required
067 *
068 * @param name the name of the property
069 * @param type the type of the property
070 * @return the value of the given header or null if there is no property for
071 * the given name or null if it cannot be converted to the given
072 * type
073 */
074 <T> T getProperty(String name, Class<T> type);
075
076 /**
077 * Sets a property on the exchange
078 *
079 * @param name of the property
080 * @param value to associate with the name
081 */
082 void setProperty(String name, Object value);
083
084 /**
085 * Removes the given property on the exchange
086 *
087 * @param name of the property
088 * @return the old value of the property
089 */
090 Object removeProperty(String name);
091
092 /**
093 * Returns all of the properties associated with the exchange
094 *
095 * @return all the headers in a Map
096 */
097 Map<String, Object> getProperties();
098
099 /**
100 * Returns the inbound request message
101 *
102 * @return the message
103 */
104 Message getIn();
105
106 /**
107 * Sets the inbound message instance
108 *
109 * @param in the inbound message
110 */
111 void setIn(Message in);
112
113 /**
114 * Returns the outbound message, lazily creating one if one has not already
115 * been associated with this exchange. If you want to inspect this property
116 * but not force lazy creation then invoke the {@link #getOut(boolean)}
117 * method passing in <tt>false</tt>
118 *
119 * @return the response
120 */
121 Message getOut();
122
123 /**
124 * Returns the outbound message; optionally lazily creating one if one has
125 * not been associated with this exchange
126 *
127 * @param lazyCreate <tt>true</tt> will lazy create the out message
128 * @return the response
129 */
130 Message getOut(boolean lazyCreate);
131
132 /**
133 * Sets the outbound message
134 *
135 * @param out the outbound message
136 */
137 void setOut(Message out);
138
139 /**
140 * Returns the fault message
141 *
142 * @return the fault
143 */
144 Message getFault();
145
146 /**
147 * Returns the fault message; optionally lazily creating one if one has
148 * not been associated with this exchange
149 *
150 * @param lazyCreate <tt>true</tt> will lazy create the fault message
151 * @return the fault
152 */
153 Message getFault(boolean lazyCreate);
154
155 /**
156 * Returns the exception associated with this exchange
157 *
158 * @return the exception (or null if no faults)
159 */
160 Throwable getException();
161
162 /**
163 * Sets the exception associated with this exchange
164 *
165 * @param e the caused exception
166 */
167 void setException(Throwable e);
168
169 /**
170 * Returns true if this exchange failed due to either an exception or fault
171 *
172 * @return true if this exchange failed due to either an exception or fault
173 * @see Exchange#getException()
174 * @see Exchange#getFault()
175 */
176 boolean isFailed();
177
178 /**
179 * Returns true if this exchange is transacted
180 */
181 boolean isTransacted();
182
183 /**
184 * Returns the container so that a processor can resolve endpoints from URIs
185 *
186 * @return the container which owns this exchange
187 */
188 CamelContext getContext();
189
190 /**
191 * Creates a new exchange instance with empty messages, headers and properties
192 */
193 Exchange newInstance();
194
195 /**
196 * Creates a copy of the current message exchange so that it can be
197 * forwarded to another destination
198 */
199 Exchange copy();
200
201 /**
202 * Copies the data into this exchange from the given exchange
203 *
204 * @param source is the source from which headers and messages will be copied
205 */
206 void copyFrom(Exchange source);
207
208 /**
209 * Returns the unit of work that this exchange belongs to; which may map to
210 * zero, one or more physical transactions
211 */
212 UnitOfWork getUnitOfWork();
213
214 /**
215 * Sets the unit of work that this exchange belongs to; which may map to
216 * zero, one or more physical transactions
217 */
218 void setUnitOfWork(UnitOfWork unitOfWork);
219
220 /**
221 * Returns the exchange id (unique)
222 */
223 String getExchangeId();
224
225 /**
226 * Set the exchange id
227 */
228 void setExchangeId(String id);
229
230 }