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 */
017package org.apache.camel;
018
019import java.util.List;
020import java.util.Map;
021
022import org.apache.camel.spi.Synchronization;
023import org.apache.camel.spi.UnitOfWork;
024
025/**
026 * An Exchange is the message container holding the information during the entire routing of
027 * a {@link  Message} received by a {@link Consumer}. 
028 * <p/>
029 * During processing down the {@link Processor} chain, the {@link Exchange} provides access to the 
030 * current (not the original) request and response {@link Message} messages. The {@link Exchange} 
031 * also holds meta-data during its entire lifetime stored as properties accessible using the 
032 * various {@link #getProperty(String)} methods. The {@link #setProperty(String, Object)} is 
033 * used to store a property. For example you can use this to store security, SLA related 
034 * data or any other information deemed useful throughout processing. If an {@link Exchange} 
035 * failed during routing the {@link Exception} that caused the failure is stored and accessible 
036 * via the {@link #getException()} method.
037 * <p/>
038 * An Exchange is created when a {@link Consumer} receives a request. A new {@link Message} is
039 * created, the request is set as the body of the {@link Message} and depending on the {@link Consumer}
040 * other {@link Endpoint} and protocol related information is added as headers on the {@link Message}.
041 * Then an Exchange is created and the newly created {@link Message} is set as the in on the Exchange.
042 * Therefore an Exchange starts its life in a {@link Consumer}. The Exchange is then sent down the
043 * {@link Route} for processing along a {@link Processor} chain. The {@link Processor} as the name
044 * suggests is what processes the {@link Message} in the Exchange and Camel, in addition to 
045 * providing out-of-the-box a large number of useful processors, it also allows you to create your own. 
046 * The rule Camel uses is to take the out {@link Message} produced by the previous {@link Processor} 
047 * and set it as the in for the next {@link Processor}. If the previous {@link Processor} did not
048 * produce an out, then the in of the previous {@link Processor} is sent as the next in. At the
049 * end of the processing chain, depending on the {@link ExchangePattern Message Exchange Pattern} (or MEP)
050 * the last out (or in of no out available) is sent by the {@link Consumer} back to the original caller.
051 * <p/>
052 * Camel, in addition to providing out-of-the-box a large number of useful processors, it also allows 
053 * you to implement and use your own. When the Exchange is passed to a {@link Processor}, it always 
054 * contains an in {@link Message} and no out {@link Message}. The {@link Processor} <b>may</b> produce 
055 * an out, depending on the nature of the {@link Processor}. The in {@link Message} can be accessed 
056 * using the {@link #getIn()} method. Since the out message is null when entering the {@link Processor}, 
057 * the {@link #getOut()} method is actually a convenient factory method that will lazily instantiate a 
058 * {@link org.apache.camel.impl.DefaultMessage} which you could populate. As an alternative you could 
059 * also instantiate your specialized  {@link Message} and set it on the exchange using the 
060 * {@link #setOut(org.apache.camel.Message)} method. Please note that a {@link Message} contains not only 
061 * the body but also headers and attachments. If you are creating a new {@link Message} the headers and 
062 * attachments of the in {@link Message} are not automatically copied to the out by Camel and you'll have 
063 * to set the headers and attachments you need yourself. If your {@link Processor} is not producing a 
064 * different {@link Message} but only needs to slightly  modify the in, you can simply update the in 
065 * {@link Message} returned by {@link #getIn()}. 
066 * <p/>
067 * See this <a href="http://camel.apache.org/using-getin-or-getout-methods-on-exchange.html">FAQ entry</a> 
068 * for more details.
069 * 
070 */
071public interface Exchange {
072
073    String AUTHENTICATION                   = "CamelAuthentication";
074    String AUTHENTICATION_FAILURE_POLICY_ID = "CamelAuthenticationFailurePolicyId";
075    @Deprecated
076    String ACCEPT_CONTENT_TYPE              = "CamelAcceptContentType";
077    String AGGREGATED_SIZE                  = "CamelAggregatedSize";
078    String AGGREGATED_TIMEOUT               = "CamelAggregatedTimeout";
079    String AGGREGATED_COMPLETED_BY          = "CamelAggregatedCompletedBy";
080    String AGGREGATED_CORRELATION_KEY       = "CamelAggregatedCorrelationKey";
081    String AGGREGATED_COLLECTION_GUARD      = "CamelAggregatedCollectionGuard";
082    String AGGREGATION_STRATEGY             = "CamelAggregationStrategy";
083    String AGGREGATION_COMPLETE_CURRENT_GROUP = "CamelAggregationCompleteCurrentGroup";
084    String AGGREGATION_COMPLETE_ALL_GROUPS  = "CamelAggregationCompleteAllGroups";
085    String AGGREGATION_COMPLETE_ALL_GROUPS_INCLUSIVE  = "CamelAggregationCompleteAllGroupsInclusive";
086    String ASYNC_WAIT                       = "CamelAsyncWait";
087
088    String BATCH_INDEX                = "CamelBatchIndex";
089    String BATCH_SIZE                 = "CamelBatchSize";
090    String BATCH_COMPLETE             = "CamelBatchComplete";
091    String BEAN_METHOD_NAME           = "CamelBeanMethodName";
092    String BEAN_MULTI_PARAMETER_ARRAY = "CamelBeanMultiParameterArray";
093    String BINDING                    = "CamelBinding";
094    // do not prefix with Camel and use lower-case starting letter as its a shared key
095    // used across other Apache products such as AMQ, SMX etc.
096    String BREADCRUMB_ID              = "breadcrumbId";
097
098    String CHARSET_NAME          = "CamelCharsetName";
099    String CIRCUIT_BREAKER_STATE = "CamelCircuitBreakerState";
100    String CREATED_TIMESTAMP     = "CamelCreatedTimestamp";
101    String CONTENT_ENCODING      = "Content-Encoding";
102    String CONTENT_LENGTH        = "Content-Length";
103    String CONTENT_TYPE          = "Content-Type";
104    String COOKIE_HANDLER        = "CamelCookieHandler";
105    String CORRELATION_ID        = "CamelCorrelationId";
106
107    String DATASET_INDEX             = "CamelDataSetIndex";
108    String DEFAULT_CHARSET_PROPERTY  = "org.apache.camel.default.charset";
109    String DESTINATION_OVERRIDE_URL = "CamelDestinationOverrideUrl";
110    String DISABLE_HTTP_STREAM_CACHE = "CamelDisableHttpStreamCache";
111    String DUPLICATE_MESSAGE         = "CamelDuplicateMessage";
112    
113    String DOCUMENT_BUILDER_FACTORY = "CamelDocumentBuilderFactory";
114
115    String EXCEPTION_CAUGHT              = "CamelExceptionCaught";
116    String EXCEPTION_HANDLED             = "CamelExceptionHandled";
117    String EVALUATE_EXPRESSION_RESULT    = "CamelEvaluateExpressionResult";
118    String ERRORHANDLER_CIRCUIT_DETECTED = "CamelFErrorHandlerCircuitDetected";
119    String ERRORHANDLER_HANDLED          = "CamelErrorHandlerHandled";
120    String EXTERNAL_REDELIVERED          = "CamelExternalRedelivered";
121
122    String FAILURE_HANDLED      = "CamelFailureHandled";
123    String FAILURE_ENDPOINT     = "CamelFailureEndpoint";
124    String FAILURE_ROUTE_ID     = "CamelFailureRouteId";
125    String FATAL_FALLBACK_ERROR_HANDLER  = "CamelFatalFallbackErrorHandler";
126    String FILE_CONTENT_TYPE    = "CamelFileContentType";
127    String FILE_LOCAL_WORK_PATH = "CamelFileLocalWorkPath";
128    String FILE_NAME            = "CamelFileName";
129    String FILE_NAME_ONLY       = "CamelFileNameOnly";
130    String FILE_NAME_PRODUCED   = "CamelFileNameProduced";
131    String FILE_NAME_CONSUMED   = "CamelFileNameConsumed";
132    String FILE_PATH            = "CamelFilePath";
133    String FILE_PARENT          = "CamelFileParent";
134    String FILE_LAST_MODIFIED   = "CamelFileLastModified";
135    String FILE_LENGTH          = "CamelFileLength";
136    String FILE_LOCK_FILE_ACQUIRED = "CamelFileLockFileAcquired";
137    String FILE_LOCK_FILE_NAME  = "CamelFileLockFileName";
138    String FILE_LOCK_EXCLUSIVE_LOCK = "CamelFileLockExclusiveLock";
139    String FILE_LOCK_RANDOM_ACCESS_FILE = "CamelFileLockRandomAccessFile";
140    String FILTER_MATCHED       = "CamelFilterMatched";
141    String FILTER_NON_XML_CHARS = "CamelFilterNonXmlChars";
142
143    String GROUPED_EXCHANGE = "CamelGroupedExchange";
144    
145    String HTTP_BASE_URI           = "CamelHttpBaseUri";
146    String HTTP_CHARACTER_ENCODING = "CamelHttpCharacterEncoding";
147    String HTTP_METHOD             = "CamelHttpMethod";
148    String HTTP_PATH               = "CamelHttpPath";
149    String HTTP_PROTOCOL_VERSION   = "CamelHttpProtocolVersion";
150    String HTTP_QUERY              = "CamelHttpQuery";
151    String HTTP_RAW_QUERY          = "CamelHttpRawQuery";
152    String HTTP_RESPONSE_CODE      = "CamelHttpResponseCode";
153    String HTTP_RESPONSE_TEXT      = "CamelHttpResponseText";
154    String HTTP_URI                = "CamelHttpUri";
155    String HTTP_URL                = "CamelHttpUrl";
156    String HTTP_CHUNKED            = "CamelHttpChunked";
157    String HTTP_SERVLET_REQUEST    = "CamelHttpServletRequest";
158    String HTTP_SERVLET_RESPONSE   = "CamelHttpServletResponse";
159
160    String INTERCEPTED_ENDPOINT = "CamelInterceptedEndpoint";
161    String INTERCEPT_SEND_TO_ENDPOINT_WHEN_MATCHED = "CamelInterceptSendToEndpointWhenMatched";
162
163    String LANGUAGE_SCRIPT          = "CamelLanguageScript";
164    String LOG_DEBUG_BODY_MAX_CHARS = "CamelLogDebugBodyMaxChars";
165    String LOG_DEBUG_BODY_STREAMS   = "CamelLogDebugStreams";
166    String LOG_EIP_NAME             = "CamelLogEipName";
167    String LOOP_INDEX               = "CamelLoopIndex";
168    String LOOP_SIZE                = "CamelLoopSize";
169
170    String MAXIMUM_CACHE_POOL_SIZE     = "CamelMaximumCachePoolSize";
171    String MAXIMUM_ENDPOINT_CACHE_SIZE = "CamelMaximumEndpointCacheSize";
172    String MAXIMUM_TRANSFORMER_CACHE_SIZE = "CamelMaximumTransformerCacheSize";
173    String MAXIMUM_VALIDATOR_CACHE_SIZE = "CamelMaximumValidatorCacheSize";
174    String MESSAGE_HISTORY             = "CamelMessageHistory";
175    String MESSAGE_HISTORY_HEADER_FORMAT      = "CamelMessageHistoryHeaderFormat";
176    String MESSAGE_HISTORY_OUTPUT_FORMAT      = "CamelMessageHistoryOutputFormat";
177    String MULTICAST_INDEX             = "CamelMulticastIndex";
178    String MULTICAST_COMPLETE          = "CamelMulticastComplete";
179
180    String NOTIFY_EVENT = "CamelNotifyEvent";
181
182    String ON_COMPLETION      = "CamelOnCompletion";
183    String OVERRULE_FILE_NAME = "CamelOverruleFileName";
184
185    String PARENT_UNIT_OF_WORK = "CamelParentUnitOfWork";
186    String STREAM_CACHE_UNIT_OF_WORK = "CamelStreamCacheUnitOfWork";
187    
188    String RECIPIENT_LIST_ENDPOINT = "CamelRecipientListEndpoint";
189    String RECEIVED_TIMESTAMP      = "CamelReceivedTimestamp";
190    String REDELIVERED             = "CamelRedelivered";
191    String REDELIVERY_COUNTER      = "CamelRedeliveryCounter";
192    String REDELIVERY_MAX_COUNTER  = "CamelRedeliveryMaxCounter";
193    String REDELIVERY_EXHAUSTED    = "CamelRedeliveryExhausted";
194    String REDELIVERY_DELAY        = "CamelRedeliveryDelay";
195    String REST_HTTP_URI           = "CamelRestHttpUri";
196    String REST_HTTP_QUERY         = "CamelRestHttpQuery";
197    String ROLLBACK_ONLY           = "CamelRollbackOnly";
198    String ROLLBACK_ONLY_LAST      = "CamelRollbackOnlyLast";
199    String ROUTE_STOP              = "CamelRouteStop";
200
201    String REUSE_SCRIPT_ENGINE = "CamelReuseScripteEngine";
202    String COMPILE_SCRIPT = "CamelCompileScript";
203    
204    String SAXPARSER_FACTORY   = "CamelSAXParserFactory";
205
206    String SCHEDULER_POLLED_MESSAGES = "CamelSchedulerPolledMessages";
207    String SOAP_ACTION        = "CamelSoapAction";
208    String SKIP_GZIP_ENCODING = "CamelSkipGzipEncoding";
209    String SKIP_WWW_FORM_URLENCODED = "CamelSkipWwwFormUrlEncoding"; 
210    String SLIP_ENDPOINT      = "CamelSlipEndpoint";
211    String SPLIT_INDEX        = "CamelSplitIndex";
212    String SPLIT_COMPLETE     = "CamelSplitComplete";
213    String SPLIT_SIZE         = "CamelSplitSize";
214
215    String TIMER_COUNTER         = "CamelTimerCounter";
216    String TIMER_FIRED_TIME      = "CamelTimerFiredTime";
217    String TIMER_NAME            = "CamelTimerName";
218    String TIMER_PERIOD          = "CamelTimerPeriod";
219    String TIMER_TIME            = "CamelTimerTime";
220    String TO_ENDPOINT           = "CamelToEndpoint";
221    String TRACE_EVENT           = "CamelTraceEvent";
222    String TRACE_EVENT_NODE_ID   = "CamelTraceEventNodeId";
223    String TRACE_EVENT_TIMESTAMP = "CamelTraceEventTimestamp";
224    String TRACE_EVENT_EXCHANGE  = "CamelTraceEventExchange";
225    String TRY_ROUTE_BLOCK       = "TryRouteBlock";
226    String TRANSFER_ENCODING     = "Transfer-Encoding";
227
228    String UNIT_OF_WORK_EXHAUSTED    = "CamelUnitOfWorkExhausted";
229    
230    /**
231     * @deprecated UNIT_OF_WORK_PROCESS_SYNC is not in use and will be removed in future Camel release
232     */
233    @Deprecated
234    String UNIT_OF_WORK_PROCESS_SYNC = "CamelUnitOfWorkProcessSync";
235
236    String XSLT_FILE_NAME   = "CamelXsltFileName";
237    String XSLT_ERROR       = "CamelXsltError";
238    String XSLT_FATAL_ERROR = "CamelXsltFatalError";
239    String XSLT_WARNING     = "CamelXsltWarning";
240
241    /**
242     * Returns the {@link ExchangePattern} (MEP) of this exchange.
243     *
244     * @return the message exchange pattern of this exchange
245     */
246    ExchangePattern getPattern();
247
248    /**
249     * Allows the {@link ExchangePattern} (MEP) of this exchange to be customized.
250     *
251     * This typically won't be required as an exchange can be created with a specific MEP
252     * by calling {@link Endpoint#createExchange(ExchangePattern)} but it is here just in case
253     * it is needed.
254     *
255     * @param pattern  the pattern 
256     */
257    void setPattern(ExchangePattern pattern);
258
259    /**
260     * Returns a property associated with this exchange by name
261     *
262     * @param name the name of the property
263     * @return the value of the given property or <tt>null</tt> if there is no property for
264     *         the given name
265     */
266    Object getProperty(String name);
267
268    /**
269     * Returns a property associated with this exchange by name
270     *
271     * @param name the name of the property
272     * @param defaultValue the default value to return if property was absent
273     * @return the value of the given property or <tt>defaultValue</tt> if there is no
274     *         property for the given name
275     */
276    Object getProperty(String name, Object defaultValue);
277
278    /**
279     * Returns a property associated with this exchange by name and specifying
280     * the type required
281     *
282     * @param name the name of the property
283     * @param type the type of the property
284     * @return the value of the given property or <tt>null</tt> if there is no property for
285     *         the given name or <tt>null</tt> if it cannot be converted to the given type
286     */
287    <T> T getProperty(String name, Class<T> type);
288
289    /**
290     * Returns a property associated with this exchange by name and specifying
291     * the type required
292     *
293     * @param name the name of the property
294     * @param defaultValue the default value to return if property was absent
295     * @param type the type of the property
296     * @return the value of the given property or <tt>defaultValue</tt> if there is no property for
297     *         the given name or <tt>null</tt> if it cannot be converted to the given type
298     */
299    <T> T getProperty(String name, Object defaultValue, Class<T> type);
300
301    /**
302     * Sets a property on the exchange
303     *
304     * @param name  of the property
305     * @param value to associate with the name
306     */
307    void setProperty(String name, Object value);
308
309    /**
310     * Removes the given property on the exchange
311     *
312     * @param name of the property
313     * @return the old value of the property
314     */
315    Object removeProperty(String name);
316
317    /**
318     * Remove all of the properties associated with the exchange matching a specific pattern
319     *
320     * @param pattern pattern of names
321     * @return boolean whether any properties matched
322     */
323    boolean removeProperties(String pattern);
324    
325    /**
326     * Removes the properties from this exchange that match the given <tt>pattern</tt>, 
327     * except for the ones matching one ore more <tt>excludePatterns</tt>
328     * 
329     * @param pattern pattern of names that should be removed
330     * @param excludePatterns one or more pattern of properties names that should be excluded (= preserved)
331     * @return boolean whether any properties matched
332     */ 
333    boolean removeProperties(String pattern, String... excludePatterns);
334    
335    /**
336     * Returns all of the properties associated with the exchange
337     *
338     * @return all the headers in a Map
339     */
340    Map<String, Object> getProperties();
341
342    /**
343     * Returns whether any properties has been set
344     *
345     * @return <tt>true</tt> if any properties has been set
346     */
347    boolean hasProperties();
348
349    /**
350     * Returns the inbound request message
351     *
352     * @return the message
353     */
354    Message getIn();
355
356    /**
357     * Returns the inbound request message as the given type
358     *
359     * @param type the given type
360     * @return the message as the given type or <tt>null</tt> if not possible to covert to given type
361     */
362    <T> T getIn(Class<T> type);
363
364    /**
365     * Sets the inbound message instance
366     *
367     * @param in the inbound message
368     */
369    void setIn(Message in);
370
371    /**
372     * Returns the outbound message, lazily creating one if one has not already
373     * been associated with this exchange.
374     * <p/>
375     * <br/><b>Important:</b> If you want to change the current message, then use {@link #getIn()} instead as it will
376     * ensure headers etc. is kept and propagated when routing continues. Bottom line end users should rarely use
377     * this method.
378     * <p/>
379     * <br/>If you want to test whether an OUT message have been set or not, use the {@link #hasOut()} method.
380     * <p/>
381     * See also the class java doc for this {@link Exchange} for more details and this
382     * <a href="http://camel.apache.org/using-getin-or-getout-methods-on-exchange.html">FAQ entry</a>.
383     *
384     * @return the response
385     * @see #getIn()
386     */
387    Message getOut();
388
389    /**
390     * Returns the outbound request message as the given type
391     * <p/>
392     * <br/><b>Important:</b> If you want to change the current message, then use {@link #getIn()} instead as it will
393     * ensure headers etc. is kept and propagated when routing continues. Bottom line end users should rarely use
394     * this method.
395     * <p/>
396     * <br/>If you want to test whether an OUT message have been set or not, use the {@link #hasOut()} method.
397     * <p/>
398     * See also the class java doc for this {@link Exchange} for more details and this
399     * <a href="http://camel.apache.org/using-getin-or-getout-methods-on-exchange.html">FAQ entry</a>.
400     *
401     * @param type the given type
402     * @return the message as the given type or <tt>null</tt> if not possible to covert to given type
403     * @see #getIn(Class)
404     */
405    <T> T getOut(Class<T> type);
406
407    /**
408     * Returns whether an OUT message has been set or not.
409     *
410     * @return <tt>true</tt> if an OUT message exists, <tt>false</tt> otherwise.
411     */
412    boolean hasOut();
413
414    /**
415     * Sets the outbound message
416     *
417     * @param out the outbound message
418     */
419    void setOut(Message out);
420
421    /**
422     * Returns the exception associated with this exchange
423     *
424     * @return the exception (or null if no faults)
425     */
426    Exception getException();
427
428    /**
429     * Returns the exception associated with this exchange.
430     * <p/>
431     * Is used to get the caused exception that typically have been wrapped in some sort
432     * of Camel wrapper exception
433     * <p/>
434     * The strategy is to look in the exception hierarchy to find the first given cause that matches the type.
435     * Will start from the bottom (the real cause) and walk upwards.
436     *
437     * @param type the exception type
438     * @return the exception (or <tt>null</tt> if no caused exception matched)
439     */
440    <T> T getException(Class<T> type);
441
442    /**
443     * Sets the exception associated with this exchange
444     * <p/>
445     * Camel will wrap {@link Throwable} into {@link Exception} type to
446     * accommodate for the {@link #getException()} method returning a plain {@link Exception} type.
447     *
448     * @param t  the caused exception
449     */
450    void setException(Throwable t);
451
452    /**
453     * Returns true if this exchange failed due to either an exception or fault
454     *
455     * @return true if this exchange failed due to either an exception or fault
456     * @see Exchange#getException()
457     * @see Message#setFault(boolean)
458     * @see Message#isFault()
459     */
460    boolean isFailed();
461
462    /**
463     * Returns true if this exchange is transacted
464     */
465    boolean isTransacted();
466
467    /**
468     * Returns true if this exchange is an external initiated redelivered message (such as a JMS broker).
469     * <p/>
470     * <b>Important: </b> It is not always possible to determine if the message is a redelivery
471     * or not, and therefore <tt>null</tt> is returned. Such an example would be a JDBC message.
472     * However JMS brokers provides details if a message is redelivered.
473     *
474     * @return <tt>true</tt> if redelivered, <tt>false</tt> if not, <tt>null</tt> if not able to determine
475     */
476    Boolean isExternalRedelivered();
477
478    /**
479     * Returns true if this exchange is marked for rollback
480     */
481    boolean isRollbackOnly();
482
483    /**
484     * Returns the container so that a processor can resolve endpoints from URIs
485     *
486     * @return the container which owns this exchange
487     */
488    CamelContext getContext();
489
490    /**
491     * Creates a copy of the current message exchange so that it can be
492     * forwarded to another destination
493     * <p/>
494     * Notice this operation invokes <tt>copy(false)</tt>
495     */
496    Exchange copy();
497
498    /**
499     * Creates a copy of the current message exchange so that it can be
500     * forwarded to another destination
501     *
502     * @param safeCopy whether to copy exchange properties and message headers safely to a new map instance,
503     *                 or allow sharing the same map instances in the returned copy.
504     */
505    Exchange copy(boolean safeCopy);
506
507    /**
508     * Returns the endpoint which originated this message exchange if a consumer on an endpoint
509     * created the message exchange, otherwise this property will be <tt>null</tt>
510     */
511    Endpoint getFromEndpoint();
512
513    /**
514     * Sets the endpoint which originated this message exchange. This method
515     * should typically only be called by {@link org.apache.camel.Endpoint} implementations
516     *
517     * @param fromEndpoint the endpoint which is originating this message exchange
518     */
519    void setFromEndpoint(Endpoint fromEndpoint);
520    
521    /**
522     * Returns the route id which originated this message exchange if a route consumer on an endpoint
523     * created the message exchange, otherwise this property will be <tt>null</tt>
524     */
525    String getFromRouteId();
526
527    /**
528     * Sets the route id which originated this message exchange. This method
529     * should typically only be called by the internal framework.
530     *
531     * @param fromRouteId the from route id
532     */
533    void setFromRouteId(String fromRouteId);
534
535    /**
536     * Returns the unit of work that this exchange belongs to; which may map to
537     * zero, one or more physical transactions
538     */
539    UnitOfWork getUnitOfWork();
540
541    /**
542     * Sets the unit of work that this exchange belongs to; which may map to
543     * zero, one or more physical transactions
544     */
545    void setUnitOfWork(UnitOfWork unitOfWork);
546
547    /**
548     * Returns the exchange id (unique)
549     */
550    String getExchangeId();
551
552    /**
553     * Set the exchange id
554     */
555    void setExchangeId(String id);
556
557    /**
558     * Adds a {@link org.apache.camel.spi.Synchronization} to be invoked as callback when
559     * this exchange is completed.
560     *
561     * @param onCompletion  the callback to invoke on completion of this exchange
562     */
563    void addOnCompletion(Synchronization onCompletion);
564
565    /**
566     * Checks if the passed {@link org.apache.camel.spi.Synchronization} instance is
567     * already contained on this exchange.
568     *
569     * @param onCompletion  the callback instance that is being checked for
570     * @return <tt>true</tt>, if callback instance is already contained on this exchange, else <tt>false</tt>
571     */
572    boolean containsOnCompletion(Synchronization onCompletion);
573
574    /**
575     * Handover all the on completions from this exchange to the target exchange.
576     *
577     * @param target the target exchange
578     */
579    void handoverCompletions(Exchange target);
580
581    /**
582     * Handover all the on completions from this exchange
583     *
584     * @return the on completions
585     */
586    List<Synchronization> handoverCompletions();
587
588}