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: 703643 $
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 String EXCEPTION_HANDLED_PROPERTY = "CamelExceptionHandled";
038
039 /**
040 * Returns the {@link ExchangePattern} (MEP) of this exchange.
041 *
042 * @return the message exchange pattern of this exchange
043 */
044 ExchangePattern getPattern();
045
046 /**
047 * Allows the {@link ExchangePattern} (MEP) of this exchange to be customized.
048 *
049 * This typically won't be required as an exchange can be created with a specific MEP
050 * by calling {@link Endpoint#createExchange(ExchangePattern)} but it is here just in case
051 * it is needed.
052 *
053 * @param pattern the pattern
054 */
055 void setPattern(ExchangePattern pattern);
056
057 /**
058 * Returns a property associated with this exchange by name
059 *
060 * @param name the name of the property
061 * @return the value of the given header or null if there is no property for
062 * the given name
063 */
064 Object getProperty(String name);
065
066 /**
067 * Returns a property associated with this exchange by name and specifying
068 * the type required
069 *
070 * @param name the name of the property
071 * @param type the type of the property
072 * @return the value of the given header or null if there is no property for
073 * the given name or null if it cannot be converted to the given
074 * type
075 */
076 <T> T getProperty(String name, Class<T> type);
077
078 /**
079 * Sets a property on the exchange
080 *
081 * @param name of the property
082 * @param value to associate with the name
083 */
084 void setProperty(String name, Object value);
085
086 /**
087 * Removes the given property on the exchange
088 *
089 * @param name of the property
090 * @return the old value of the property
091 */
092 Object removeProperty(String name);
093
094 /**
095 * Returns all of the properties associated with the exchange
096 *
097 * @return all the headers in a Map
098 */
099 Map<String, Object> getProperties();
100
101 /**
102 * Returns the inbound request message
103 *
104 * @return the message
105 */
106 Message getIn();
107
108 /**
109 * Sets the inbound message instance
110 *
111 * @param in the inbound message
112 */
113 void setIn(Message in);
114
115 /**
116 * Returns the outbound message, lazily creating one if one has not already
117 * been associated with this exchange. If you want to inspect this property
118 * but not force lazy creation then invoke the {@link #getOut(boolean)}
119 * method passing in <tt>false</tt>
120 *
121 * @return the response
122 */
123 Message getOut();
124
125 /**
126 * Returns the outbound message; optionally lazily creating one if one has
127 * not been associated with this exchange
128 *
129 * @param lazyCreate <tt>true</tt> will lazy create the out message
130 * @return the response
131 */
132 Message getOut(boolean lazyCreate);
133
134 /**
135 * Sets the outbound message
136 *
137 * @param out the outbound message
138 */
139 void setOut(Message out);
140
141 /**
142 * Returns the fault message
143 *
144 * @return the fault
145 */
146 Message getFault();
147
148 /**
149 * Returns the fault message; optionally lazily creating one if one has
150 * not been associated with this exchange
151 *
152 * @param lazyCreate <tt>true</tt> will lazy create the fault message
153 * @return the fault
154 */
155 Message getFault(boolean lazyCreate);
156
157 /**
158 * Returns the exception associated with this exchange
159 *
160 * @return the exception (or null if no faults)
161 */
162 Throwable getException();
163
164 /**
165 * Sets the exception associated with this exchange
166 *
167 * @param e the caused exception
168 */
169 void setException(Throwable e);
170
171 /**
172 * Returns true if this exchange failed due to either an exception or fault
173 *
174 * @return true if this exchange failed due to either an exception or fault
175 * @see Exchange#getException()
176 * @see Exchange#getFault()
177 */
178 boolean isFailed();
179
180 /**
181 * Returns true if this exchange is transacted
182 */
183 boolean isTransacted();
184
185 /**
186 * Returns the container so that a processor can resolve endpoints from URIs
187 *
188 * @return the container which owns this exchange
189 */
190 CamelContext getContext();
191
192 /**
193 * Creates a new exchange instance with empty messages, headers and properties
194 */
195 Exchange newInstance();
196
197 /**
198 * Creates a copy of the current message exchange so that it can be
199 * forwarded to another destination
200 */
201 Exchange copy();
202
203 /**
204 * Copies the data into this exchange from the given exchange
205 *
206 * @param source is the source from which headers and messages will be copied
207 */
208 void copyFrom(Exchange source);
209
210 /**
211 * Returns the unit of work that this exchange belongs to; which may map to
212 * zero, one or more physical transactions
213 */
214 UnitOfWork getUnitOfWork();
215
216 /**
217 * Sets the unit of work that this exchange belongs to; which may map to
218 * zero, one or more physical transactions
219 */
220 void setUnitOfWork(UnitOfWork unitOfWork);
221
222 /**
223 * Returns the exchange id (unique)
224 */
225 String getExchangeId();
226
227 /**
228 * Set the exchange id
229 */
230 void setExchangeId(String id);
231
232 }