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: 47622 $
030 */
031 public interface Exchange {
032
033 String CHARSET_NAME = "org.apache.camel.Exchange.CharsetName";
034
035 /**
036 * Returns the {@link ExchangePattern} (MEP) of this exchange.
037 *
038 * @return the message exchange pattern of this exchange
039 */
040 ExchangePattern getPattern();
041
042 /**
043 * Allows the {@link ExchangePattern} (MEP) of this exchange to be customized.
044 *
045 * This typically won't be required as an exchange can be created with a specific MEP
046 * by calling {@link Endpoint#createExchange(ExchangePattern)} but it is here just in case
047 * it is needed.
048 */
049 void setPattern(ExchangePattern pattern);
050
051 /**
052 * Returns a property associated with this exchange by name
053 *
054 * @param name the name of the property
055 * @return the value of the given header or null if there is no property for
056 * the given name
057 */
058 Object getProperty(String name);
059
060 /**
061 * Returns a property associated with this exchange by name and specifying
062 * the type required
063 *
064 * @param name the name of the property
065 * @param type the type of the property
066 * @return the value of the given header or null if there is no property for
067 * the given name or null if it cannot be converted to the given
068 * type
069 */
070 <T> T getProperty(String name, Class<T> type);
071
072 /**
073 * Sets a property on the exchange
074 *
075 * @param name of the property
076 * @param value to associate with the name
077 */
078 void setProperty(String name, Object value);
079
080 /**
081 * Removes the given property on the exchange
082 *
083 * @param name of the property
084 * @return the old value of the property
085 */
086 Object removeProperty(String name);
087
088 /**
089 * Returns all of the properties associated with the exchange
090 *
091 * @return all the headers in a Map
092 */
093 Map<String, Object> getProperties();
094
095 /**
096 * Returns the inbound request message
097 *
098 * @return the message
099 */
100 Message getIn();
101
102 /**
103 * Sets the inbound message instance
104 *
105 * @param in the inbound message
106 */
107 void setIn(Message in);
108
109 /**
110 * Returns the outbound message, lazily creating one if one has not already
111 * been associated with this exchange. If you want to inspect this property
112 * but not force lazy creation then invoke the {@link #getOut(boolean)}
113 * method passing in <tt>false</tt>
114 *
115 * @return the response
116 */
117 Message getOut();
118
119 /**
120 * Returns the outbound message; optionally lazily creating one if one has
121 * not been associated with this exchange
122 *
123 * @return the response
124 */
125 Message getOut(boolean lazyCreate);
126
127 /**
128 * Sets the outbound message
129 *
130 * @param out the outbound message
131 */
132 void setOut(Message out);
133
134 /**
135 * Returns the fault message
136 *
137 * @return the fault
138 */
139 Message getFault();
140
141 /**
142 * Returns the fault message; optionally lazily creating one if one has
143 * not been associated with this exchange
144 *
145 * @param lazyCreate <tt>true</tt> will lazy create the fault message
146 *
147 * @return the fault
148 */
149 Message getFault(boolean lazyCreate);
150
151 /**
152 * Returns the exception associated with this exchange
153 *
154 * @return the exception (or null if no faults)
155 */
156 Throwable getException();
157
158 /**
159 * Sets the exception associated with this exchange
160 *
161 * @param e the caused exception
162 */
163 void setException(Throwable e);
164
165 /**
166 * Returns true if this exchange failed due to either an exception or fault
167 *
168 * @return true if this exchange failed due to either an exception or fault
169 * @see Exchange#getException()
170 * @see Exchange#getFault()
171 */
172 boolean isFailed();
173
174 /**
175 * Returns true if this exchange is transacted
176 */
177 boolean isTransacted();
178
179 /**
180 * Returns the container so that a processor can resolve endpoints from URIs
181 *
182 * @return the container which owns this exchange
183 */
184 CamelContext getContext();
185
186 /**
187 * Creates a new exchange instance with empty messages, headers and properties
188 */
189 Exchange newInstance();
190
191 /**
192 * Creates a copy of the current message exchange so that it can be
193 * forwarded to another destination
194 */
195 Exchange copy();
196
197 /**
198 * Copies the data into this exchange from the given exchange
199 *
200 * @param source is the source from which headers and messages will be copied
201 */
202 void copyFrom(Exchange source);
203
204 /**
205 * Returns the unit of work that this exchange belongs to; which may map to
206 * zero, one or more physical transactions
207 */
208 UnitOfWork getUnitOfWork();
209
210 /**
211 * Sets the unit of work that this exchange belongs to; which may map to
212 * zero, one or more physical transactions
213 */
214 void setUnitOfWork(UnitOfWork unitOfWork);
215
216 /**
217 * Returns the exchange id
218 *
219 * @return the unique id of the exchange
220 */
221 String getExchangeId();
222
223 /**
224 * Set the exchange id
225 *
226 * @param id
227 */
228 void setExchangeId(String id);
229
230 }