Author: buildbot
Date: Sat Feb 4 01:20:14 2017
New Revision: 1006186
Log:
Production update by buildbot for camel
Modified:
websites/production/camel/content/book-in-one-page.html
websites/production/camel/content/book-pattern-appendix.html
websites/production/camel/content/cache/main.pageCache
websites/production/camel/content/dead-letter-channel.html
websites/production/camel/content/error-handler.html
Modified: websites/production/camel/content/book-in-one-page.html
==============================================================================
--- websites/production/camel/content/book-in-one-page.html (original)
+++ websites/production/camel/content/book-in-one-page.html Sat Feb 4 01:20:14
2017
@@ -3930,11 +3930,11 @@ The tutorial has been designed in two pa
While not actual tutorials you might find working through the source of the
various <a shape="rect" href="examples.html">Examples</a> useful.</li></ul>
<h2 id="BookInOnePage-TutorialonSpringRemotingwithJMS">Tutorial on Spring
Remoting with JMS</h2><p> </p><div class="confluence-information-macro
confluence-information-macro-information"><p class="title">Thanks</p><span
class="aui-icon aui-icon-small aui-iconfont-info
confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>This tutorial was kindly donated
to Apache Camel by Martin Gilday.</p></div></div><h2
id="BookInOnePage-Preface">Preface</h2><p>This tutorial aims to guide the
reader through the stages of creating a project which uses Camel to facilitate
the routing of messages from a JMS queue to a <a shape="rect"
class="external-link" href="http://www.springramework.org";
rel="nofollow">Spring</a> service. The route works in a synchronous fashion
returning a response to the client.</p><p><style type="text/css">/*<![CDATA[*/
-div.rbtoc1485983947663 {padding: 0px;}
-div.rbtoc1485983947663 ul {list-style: disc;margin-left: 0px;}
-div.rbtoc1485983947663 li {margin-left: 0px;padding-left: 0px;}
+div.rbtoc1486171101204 {padding: 0px;}
+div.rbtoc1486171101204 ul {list-style: disc;margin-left: 0px;}
+div.rbtoc1486171101204 li {margin-left: 0px;padding-left: 0px;}
-/*]]>*/</style></p><div class="toc-macro rbtoc1485983947663">
+/*]]>*/</style></p><div class="toc-macro rbtoc1486171101204">
<ul class="toc-indentation"><li><a shape="rect"
href="#BookInOnePage-TutorialonSpringRemotingwithJMS">Tutorial on Spring
Remoting with JMS</a></li><li><a shape="rect"
href="#BookInOnePage-Preface">Preface</a></li><li><a shape="rect"
href="#BookInOnePage-Prerequisites">Prerequisites</a></li><li><a shape="rect"
href="#BookInOnePage-Distribution">Distribution</a></li><li><a shape="rect"
href="#BookInOnePage-About">About</a></li><li><a shape="rect"
href="#BookInOnePage-CreatetheCamelProject">Create the Camel Project</a>
<ul class="toc-indentation"><li><a shape="rect"
href="#BookInOnePage-UpdatethePOMwithDependencies">Update the POM with
Dependencies</a></li></ul>
</li><li><a shape="rect" href="#BookInOnePage-WritingtheServer">Writing the
Server</a>
@@ -6049,11 +6049,11 @@ So we completed the last piece in the pi
<p>This example has been removed from <strong>Camel 2.9</strong> onwards.
Apache Axis 1.4 is a very old and unsupported framework. We encourage users to
use <a shape="rect" href="cxf.html">CXF</a> instead of Axis.</p></div></div>
<style type="text/css">/*<![CDATA[*/
-div.rbtoc1485983948107 {padding: 0px;}
-div.rbtoc1485983948107 ul {list-style: disc;margin-left: 0px;}
-div.rbtoc1485983948107 li {margin-left: 0px;padding-left: 0px;}
+div.rbtoc1486171101652 {padding: 0px;}
+div.rbtoc1486171101652 ul {list-style: disc;margin-left: 0px;}
+div.rbtoc1486171101652 li {margin-left: 0px;padding-left: 0px;}
-/*]]>*/</style><div class="toc-macro rbtoc1485983948107">
+/*]]>*/</style><div class="toc-macro rbtoc1486171101652">
<ul class="toc-indentation"><li><a shape="rect"
href="#BookInOnePage-TutorialusingAxis1.4withApacheCamel">Tutorial using Axis
1.4 with Apache Camel</a>
<ul class="toc-indentation"><li><a shape="rect"
href="#BookInOnePage-Prerequisites">Prerequisites</a></li><li><a shape="rect"
href="#BookInOnePage-Distribution">Distribution</a></li><li><a shape="rect"
href="#BookInOnePage-Introduction">Introduction</a></li><li><a shape="rect"
href="#BookInOnePage-SettinguptheprojecttorunAxis">Setting up the project to
run Axis</a>
<ul class="toc-indentation"><li><a shape="rect"
href="#BookInOnePage-Maven2">Maven 2</a></li><li><a shape="rect"
href="#BookInOnePage-wsdl">wsdl</a></li><li><a shape="rect"
href="#BookInOnePage-ConfiguringAxis">Configuring Axis</a></li><li><a
shape="rect" href="#BookInOnePage-RunningtheExample">Running the
Example</a></li></ul>
@@ -11834,49 +11834,49 @@ from("direct:start")
<script class="brush: xml; gutter: false; theme: Default"
type="syntaxhighlighter"> &lt;camelContext
errorHandlerRef=&quot;errorHandler&quot;
xmlns=&quot;http://camel.apache.org/schema/spring&quot;&gt;
&lt;route&gt; &lt;from uri=&quot;direct:a&quot;/&gt;
&lt;multicast&gt; &lt;to uri=&quot;direct:b&quot;/&gt;
&lt;to uri=&quot;direct:c&quot;/&gt; &lt;to
uri=&quot;direct:d&quot;/&gt; &lt;/multicast&gt;
&lt;/route&gt; &lt;/camelContext&gt; </script>
</div>
</div><h4 id="BookInOnePage-UsingThisPattern.7">Using This Pattern</h4><p>If
you would like to use this EIP Pattern then please read the <a shape="rect"
href="getting-started.html">Getting Started</a>, you may also find the <a
shape="rect" href="architecture.html">Architecture</a> useful particularly the
description of <a shape="rect" href="endpoint.html">Endpoint</a> and <a
shape="rect" href="uris.html">URIs</a>. Then you could try out some of the <a
shape="rect" href="examples.html">Examples</a> first before trying this pattern
out.</p><h2 id="BookInOnePage-DeadLetterChannel">Dead Letter
Channel</h2><p>Camel supports the <a shape="rect" class="external-link"
href="http://www.enterpriseintegrationpatterns.com/DeadLetterChannel.html";
rel="nofollow">Dead Letter Channel</a> from the <a shape="rect"
href="enterprise-integration-patterns.html">EIP patterns</a> using the <a
shape="rect" class="external-link"
href="http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/
processor/DeadLetterChannel.html">DeadLetterChannel</a> processor which is an
<a shape="rect" href="error-handler.html">Error Handler</a>.</p><p><span
class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image
confluence-external-resource"
src="http://www.enterpriseintegrationpatterns.com/img/DeadLetterChannelSolution.gif";
data-image-src="http://www.enterpriseintegrationpatterns.com/img/DeadLetterChannelSolution.gif";></span></p><div
class="confluence-information-macro confluence-information-macro-tip">
- <p class="title">Difference between Dead Letter Channel and Default Error
Handler</p>
+ <p class="title">Differences Between The DeadLetterChannel And The
DefaultErrorHandler</p>
<span class="aui-icon aui-icon-small aui-iconfont-approve
confluence-information-macro-icon"></span>
<div class="confluence-information-macro-body">
- <p>The Default Error Handler does very little: it ends the Exchange
immediately and propagates the thrown Exception back to the caller.</p>
- <p>The Dead Letter Channel lets you control behaviors including redelivery,
whether to propagate the thrown Exception to the caller (the
<strong>handled</strong> option), and where the (failed) Exchange should now be
routed to.</p>
- <p>The Dead Letter Channel is also by default configured to not be verbose
in the logs, so when a message is handled and moved to the dead letter
endpoint, then there is nothing logged. If you want some level of logging you
can use the various options on the redelivery policy / dead letter channel to
configure this. For example if you want the message history then set
logExhaustedMessageHistory=true (and logHandled=true for Camel 2.15.x or
older).</p>
- <p>When the DeadLetterChannel moves a message to the dead letter endpoint,
any new Exception thrown is by default handled by the dead letter channel as
well. This ensures that the DeadLetterChannel will always succeed. From
<strong>Camel 2.15</strong> onwards this behavior can be changed by setting the
option deadLetterHandleNewException=false. Then if a new Exception is thrown,
then the dead letter channel will fail and propagate back that new Exception
(which is the behavior of the default error handler). When a new Exception
occurs then the dead letter channel logs this at WARN level. This can be turned
off by setting logNewException=false.</p>
+ <p>The <strong><code>DefaultErrorHandler</code></strong> does very
little: it ends the Exchange immediately and propagates the thrown Exception
back to the caller.</p>
+ <p>The <strong><code>DeadLetterChannel</code></strong> lets you control
behaviors including redelivery, whether to propagate the thrown Exception to
the caller (the <strong><code>handled</code></strong> option), and where
the (failed) Exchange should now be routed to.</p>
+ <p>The <strong><code>DeadLetterChannel</code></strong> is also by
default configured to not be verbose in the logs, so when a message is handled
and moved to the dead letter endpoint, then there is nothing logged. If you
want some level of logging you can use the various options on the redelivery
policy / dead letter channel to configure this. For example if you want the
message history then
set <strong><code>logExhaustedMessageHistory=true</code></strong>
(and <strong><code>logHandled=true</code></strong> for <strong>Camel
2.15.x</strong> or older).</p>
+ <p>When the <strong><code>DeadLetterChannel</code></strong> moves a
message to the dead letter endpoint, any new Exception thrown is by default
handled by the dead letter channel as well. This ensures that
the <strong><code>DeadLetterChannel</code></strong> will always succeed.
From <strong>Camel 2.15</strong>: this behavior can be changed by setting the
option <strong><code>deadLetterHandleNewException=false</code></strong>. Then
if a new Exception is thrown, then the dead letter channel will fail and
propagate back that new Exception (which is the behavior of the default error
handler). When a new Exception occurs then the dead letter channel logs this
at <strong><code>WARN</code></strong> level. This can be turned off by
setting <strong><code>logNewException=false</code></strong>.</p>
</div>
-</div><h3 id="BookInOnePage-Redelivery">Redelivery</h3><p>It is common for a
temporary outage or database deadlock to cause a message to fail to process;
but the chances are if its tried a few more times with some time delay then it
will complete fine. So we typically wish to use some kind of redelivery policy
to decide how many times to try redeliver a message and how long to wait before
redelivery attempts.</p><p>The <a shape="rect" class="external-link"
href="http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/processor/RedeliveryPolicy.html";>RedeliveryPolicy</a>
defines how the message is to be redelivered. You can customize things
like</p><ul><li>how many times a message is attempted to be redelivered before
it is considered a failure and sent to the dead letter channel</li><li>the
initial redelivery timeout</li><li>whether or not exponential backoff is used
(i.e. the time between retries increases using a backoff
multiplier)</li><li>whether to use collisi
on avoidance to add some randomness to the timings</li><li>delay pattern (see
below for details)</li><li><strong>Camel 2.11:</strong> whether to allow
redelivery during stopping/shutdown</li></ul><p>Once all attempts at
redelivering the message fails then the message is forwarded to the dead letter
queue.</p><h3
id="BookInOnePage-AboutmovingExchangetodeadletterqueueandusinghandled">About
moving Exchange to dead letter queue and using
handled</h3><p><strong>Handled</strong> on <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a></p><p>When all attempts
of redelivery have failed the <a shape="rect" href="exchange.html">Exchange</a>
is moved to the dead letter queue (the dead letter endpoint). The exchange is
then complete and from the client point of view it was processed. As such the
<a shape="rect" href="dead-letter-channel.html">Dead Letter Channel</a> have
handled the <a shape="rect" href="exchange.html">Exchange</a>.</p><p>For
instance configuring the dead lett
er channel as:</p><p><strong>Using the <a shape="rect"
href="fluent-builders.html">Fluent Builders</a></strong></p><div class="code
panel pdl" style="border-width: 1px;">
+</div><h3 id="BookInOnePage-Redelivery">Redelivery</h3><p>It is common for a
temporary outage or database deadlock to cause a message to fail to process;
but the chances are if its tried a few more times with some time delay then it
will complete fine. So we typically wish to use some kind of redelivery policy
to decide how many times to try redeliver a message and how long to wait before
redelivery attempts.</p><p>The <a shape="rect" class="external-link"
href="http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/processor/RedeliveryPolicy.html";>RedeliveryPolicy</a>
defines how the message is to be redelivered. You can customize things
like</p><ul><li>The number of times a message is attempted to be redelivered
before it is considered a failure and sent to the dead letter
channel.</li><li>The initial redelivery timeout.</li><li>Whether or not
exponential backoff is used, i.e., the time between retries increases using a
backoff multiplier.</li><li>Whether to use
collision avoidance to add some randomness to the timings.</li><li>Delay
pattern (see below for details).</li><li><strong>Camel 2.11:</strong> Whether
to allow redelivery during stopping/shutdown.</li></ul><p>Once all attempts at
redelivering the message fails then the message is forwarded to the dead letter
queue.</p><h3
id="BookInOnePage-AboutMovingExchangetoDeadLetterQueueandUsinghandled()">About
Moving Exchange to Dead Letter Queue and
Using <strong><code>handled()</code></strong></h3><p><strong><code>handled()</code></strong>
on <a shape="rect" href="dead-letter-channel.html">Dead Letter
Channel</a></p><p>When all attempts of redelivery have failed the <a
shape="rect" href="exchange.html">Exchange</a> is moved to the dead letter
queue (the dead letter endpoint). The exchange is then complete and from the
client point of view it was processed. As such the <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> have handled the <a
shape="rect" href="exchange
.html">Exchange</a>.</p><p>For instance configuring the dead letter channel
as:</p><p><strong>Using the <a shape="rect" href="fluent-builders.html">Fluent
Builders</a></strong></p><div class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter">errorHandler(deadLetterChannel(&quot;jms:queue:dead&quot;)
.maximumRedeliveries(3).redeliveryDelay(5000)); </script>
</div>
</div><p><strong>Using the <a shape="rect"
href="spring-xml-extensions.html">Spring XML Extensions</a></strong></p><div
class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
- <script class="brush: xml; gutter: false; theme: Default"
type="syntaxhighlighter">&lt;route
errorHandlerRef=&quot;myDeadLetterErrorHandler&quot;&gt; ...
&lt;/route&gt; &lt;bean
id=&quot;myDeadLetterErrorHandler&quot;
class=&quot;org.apache.camel.builder.DeadLetterChannelBuilder&quot;&gt;
&lt;property name=&quot;deadLetterUri&quot;
value=&quot;jms:queue:dead&quot;/&gt; &lt;property
name=&quot;redeliveryPolicy&quot;
ref=&quot;myRedeliveryPolicyConfig&quot;/&gt; &lt;/bean&gt;
&lt;bean id=&quot;myRedeliveryPolicyConfig&quot;
class=&quot;org.apache.camel.processor.RedeliveryPolicy&quot;&gt;
&lt;property name=&quot;maximumRedeliveries&quot;
value=&quot;3&quot;/&gt; &lt;property
name=&quot;redeliveryDelay&quot;
value=&quot;5000&quot;/&gt; &lt;/bean&gt; </script>
+ <script class="brush: xml; gutter: false; theme: Default"
type="syntaxhighlighter">&lt;route
errorHandlerRef=&quot;myDeadLetterErrorHandler&quot;&gt;
&lt;!-- ... --&gt; &lt;/route&gt; &lt;bean
id=&quot;myDeadLetterErrorHandler&quot;
class=&quot;org.apache.camel.builder.DeadLetterChannelBuilder&quot;&gt;
&lt;property name=&quot;deadLetterUri&quot;
value=&quot;jms:queue:dead&quot;/&gt; &lt;property
name=&quot;redeliveryPolicy&quot;
ref=&quot;myRedeliveryPolicyConfig&quot;/&gt; &lt;/bean&gt;
&lt;bean id=&quot;myRedeliveryPolicyConfig&quot;
class=&quot;org.apache.camel.processor.RedeliveryPolicy&quot;&gt;
&lt;property name=&quot;maximumRedeliveries&quot;
value=&quot;3&quot;/&gt; &lt;property
name=&quot;redeliveryDelay&quot;
value=&quot;5000&quot;/&gt; &lt;/bean&gt; </script>
</div>
-</div><p>The <a shape="rect" href="dead-letter-channel.html">Dead Letter
Channel</a> above will clear the caused exception
(<code>setException(null)</code>), by moving the caused exception to a property
on the <a shape="rect" href="exchange.html">Exchange</a>, with the key
<code>Exchange.EXCEPTION_CAUGHT</code>. Then the <a shape="rect"
href="exchange.html">Exchange</a> is moved to the <code>"jms:queue:dead"</code>
destination and the client will not notice the failure.</p><h3
id="BookInOnePage-AboutmovingExchangetodeadletterqueueandusingtheoriginalmessage">About
moving Exchange to dead letter queue and using the original message</h3><p>The
option <strong>useOriginalMessage</strong> is used for routing the original
input message instead of the current message that potentially is modified
during routing.</p><p>For instance if you have this route:</p><div class="code
panel pdl" style="border-width: 1px;">
+</div><p>The <a shape="rect" href="dead-letter-channel.html">Dead Letter
Channel</a> above will clear the caused exception
<strong><code>setException(null)</code></strong>, by moving the caused
exception to a property on the <a shape="rect"
href="exchange.html">Exchange</a>, with the key
<strong><code>Exchange.EXCEPTION_CAUGHT</code></strong>. Then the <a
shape="rect" href="exchange.html">Exchange</a> is moved to the
<strong><code>jms:queue:dead</code></strong> destination and the client will
not notice the failure.</p><h3
id="BookInOnePage-AboutMovingExchangetoDeadLetterQueueandUsingtheOriginalMessage">About
Moving Exchange to Dead Letter Queue and Using the Original Message</h3><p>The
option <strong><code>useOriginalMessage</code></strong> is used for routing the
original input message instead of the current message that potentially is
modified during routing.</p><p>For instance if you have this route:</p><div
class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter"> from(&quot;jms:queue:order:input&quot;)
.to(&quot;bean:validateOrder&quot;)
.to(&quot;bean:transformOrder&quot;)
.to(&quot;bean:handleOrder&quot;); </script>
</div>
-</div><p>The route listen for JMS messages and validates, transforms and
handle it. During this the <a shape="rect" href="exchange.html">Exchange</a>
payload is transformed/modified. So in case something goes wrong and we want to
move the message to another JMS destination, then we can configure our <a
shape="rect" href="dead-letter-channel.html">Dead Letter Channel</a> with the
<strong>useOriginalMessage</strong> option. But when we move the <a
shape="rect" href="exchange.html">Exchange</a> to this destination we do not
know in which state the message is in. Did the error happen in before the
transformOrder or after? So to be sure we want to move the original input
message we received from <code>jms:queue:order:input</code>. So we can do this
by enabling the <strong>useOriginalMessage</strong> option as shown
below:</p><div class="code panel pdl" style="border-width: 1px;">
+</div><p>The route listen for JMS messages and validates, transforms and
handle it. During this the <a shape="rect" href="exchange.html">Exchange</a>
payload is transformed/modified. So in case something goes wrong and we want to
move the message to another JMS destination, then we can configure our <a
shape="rect" href="dead-letter-channel.html">Dead Letter Channel</a> with
the <strong><code>useOriginalMessage</code></strong> option. But when we
move the <a shape="rect" href="exchange.html">Exchange</a> to this destination
we do not know in which state the message is in. Did the error happen in before
the <strong><code>transformOrder</code></strong> or after? So to be sure
we want to move the original input message we received from
<strong><code>jms:queue:order:input</code></strong>. So we can do this by
enabling the <strong><code>useOriginalMessage</code></strong> option as
shown below:</p><div class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
- <script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter"> // will use original body
errorHandler(deadLetterChannel(&quot;jms:queue:dead&quot;)
.useOriginalMessage().maximumRedeliveries(5).redeliverDelay(5000); </script>
+ <script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter">// will use original body
errorHandler(deadLetterChannel(&quot;jms:queue:dead&quot;)
.useOriginalMessage() .maximumRedeliveries(5) .redeliverDelay(5000); </script>
</div>
-</div><p>Then the messages routed to the <code>jms:queue:dead</code> is the
original input. If we want to manually retry we can move the JMS message from
the failed to the input queue, with no problem as the message is the same as
the original we received.</p><h3
id="BookInOnePage-OnRedelivery">OnRedelivery</h3><p>When <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> is doing redeliver its
possible to configure a <a shape="rect" href="processor.html">Processor</a>
that is executed just <strong>before</strong> every redelivery attempt. This
can be used for the situations where you need to alter the message before its
redelivered. See below for sample.</p><div class="confluence-information-macro
confluence-information-macro-tip">
+</div><p>Then the messages routed to the
<strong><code>jms:queue:dead</code></strong> is the original input. If we want
to manually retry we can move the JMS message from the failed to the input
queue, with no problem as the message is the same as the original we
received.</p><h3 id="BookInOnePage-OnRedelivery">OnRedelivery</h3><p>When <a
shape="rect" href="dead-letter-channel.html">Dead Letter Channel</a> is doing
redeliver its possible to configure a <a shape="rect"
href="processor.html">Processor</a> that is executed just
<strong>before</strong> every redelivery attempt. This can be used for the
situations where you need to alter the message before its redelivered. See
below for sample.</p><div class="confluence-information-macro
confluence-information-macro-tip">
<p class="title">onException and onRedeliver</p>
<span class="aui-icon aui-icon-small aui-iconfont-approve
confluence-information-macro-icon"></span>
<div class="confluence-information-macro-body">
- <p>We also support for per <a shape="rect"
href="exception-clause.html"><strong>onException</strong></a> to set a
<strong>onRedeliver</strong>. That means you can do special on redelivery for
different exceptions, as opposed to onRedelivery set on <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> can be viewed as a
global scope.</p>
+ <p>We also support for per <a shape="rect"
href="exception-clause.html"><strong>onException</strong></a> to set an
<strong><code>onRedeliver</code></strong>. That means you can do special on
redelivery for different exceptions, as opposed
to <strong><code>onRedelivery</code></strong> set on <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> can be viewed as a
global scope.</p>
</div>
-</div><h3 id="BookInOnePage-Redeliverydefaultvalues">Redelivery default
values</h3><p>Redelivery is disabled by default.</p><p>The default redeliver
policy will use the following
values:</p><ul><li>maximumRedeliveries=0</li><li>redeliverDelay=1000L (1
second)</li><li>maximumRedeliveryDelay = 60 * 1000L (60 seconds)</li><li>And
the exponential backoff and collision avoidance is turned off.</li><li>The
retriesExhaustedLogLevel are set to LoggingLevel.ERROR</li><li>The
retryAttemptedLogLevel are set to LoggingLevel.DEBUG</li><li>Stack traces is
logged for exhausted messages from Camel 2.2 onwards.</li><li>Handled
exceptions is not logged from Camel 2.3
onwards</li><li>logExhaustedMessageHistory is true for default error handler,
and false for dead letter channel.</li><li>logExhaustedMessageBody
<strong>Camel 2.17:</strong> is disabled by default to avoid logging
sensitive message body/header details. If this option is true,
then logExhaustedMessageHistory must also be true.</
li></ul><p>The maximum redeliver delay ensures that a delay is never longer
than the value, default 1 minute. This can happen if you turn on the
exponential backoff.</p><p>The maximum redeliveries is the number of
<strong>re</strong> delivery attempts. By default Camel will try to process the
exchange 1 + 5 times. 1 time for the normal attempt and then 5 attempts as
redeliveries.<br clear="none"> Setting the maximumRedeliveries to a negative
value such as -1 will then always redelivery (unlimited).<br clear="none">
Setting the maximumRedeliveries to 0 will disable any re delivery
attempt.</p><p>Camel will log delivery failures at the DEBUG logging level by
default. You can change this by specifying retriesExhaustedLogLevel and/or
retryAttemptedLogLevel. See <a shape="rect" class="external-link"
href="http://svn.apache.org/repos/asf/camel/trunk/camel-core/src/test/java/org/apache/camel/builder/ExceptionBuilderWithRetryLoggingLevelSetTest.java";>ExceptionBuilderWithRetryLoggingLevelSet
Test</a> for an example.</p><p>You can turn logging of stack traces on/off. If
turned off Camel will still log the redelivery attempt. Its just much less
verbose.</p><h4 id="BookInOnePage-RedeliverDelayPattern">Redeliver Delay
Pattern</h4><p>Delay pattern is used as a single option to set a range pattern
for delays. If used then the following options does not apply: (delay,
backOffMultiplier, useExponentialBackOff, useCollisionAvoidance,
maximumRedeliveryDelay).</p><p>The idea is to set groups of ranges using the
following syntax: <code>limit:delay;limit 2:delay 2;limit 3:delay 3;...;limit
N:delay N</code></p><p>Each group has two values separated with colon</p><ul
class="alternate"><li>limit = upper limit</li><li>delay = delay in millis<br
clear="none"> And the groups is again separated with semi colon.<br
clear="none"> The rule of thumb is that the next groups should have a higher
limit than the previous group.</li></ul><p>Lets clarify this with an
example:<br clear="none"> <code>
delayPattern=5:1000;10:5000;20:20000</code></p><p>That gives us 3
groups:</p><ul
class="alternate"><li>5:1000</li><li>10:5000</li><li>20:20000</li></ul><p>Resulting
in these delays for redelivery attempt:</p><ul
class="alternate"><li>Redelivery attempt number 1..4 = 0 millis (as the first
group start with 5)</li><li>Redelivery attempt number 5..9 = 1000 millis (the
first group)</li><li>Redelivery attempt number 10..19 = 5000 millis (the second
group)</li><li>Redelivery attempt number 20.. = 20000 millis (the last
group)</li></ul><p>Note: The first redelivery attempt is 1, so the first group
should start with 1 or higher.</p><p>You can start a group with limit 1 to eg
have a starting delay: <code>delayPattern=1:1000;5:5000</code></p><ul
class="alternate"><li>Redelivery attempt number 1..4 = 1000 millis (the first
group)</li><li>Redelivery attempt number 5.. = 5000 millis (the last
group)</li></ul><p>There is no requirement that the next delay should be higher
than the previous. You c
an use any delay value you like. For example with
<code>delayPattern=1:5000;3:1000</code> we start with 5 sec delay and then
later reduce that to 1 second.</p><h3
id="BookInOnePage-Redeliveryheader">Redelivery header</h3><p>When a message is
redelivered the <a shape="rect" class="external-link"
href="http://camel.apache.org/maven/camel-core/apidocs/org/apache/camel/processor/DeadLetterChannel.html";>DeadLetterChannel</a>
will append a customizable header to the message to indicate how many times
its been redelivered. <br clear="none"> Before Camel 2.6: The header is
<strong>CamelRedeliveryCounter</strong>, which is also defined on the
<code>Exchange.REDELIVERY_COUNTER</code>.<br clear="none"> Starting with 2.6:
The header <strong>CamelRedeliveryMaxCounter</strong>, which is also defined on
the <code>Exchange.REDELIVERY_MAX_COUNTER</code>, contains the maximum
redelivery setting. This header is absent if you use <code>retryWhile</code> or
have unlimited maximum redelivery configured.<
/p><p>And a boolean flag whether it is being redelivered or not (first
attempt)<br clear="none"> The header <strong>CamelRedelivered</strong> contains
a boolean if the message is redelivered or not, which is also defined on the
<code>Exchange.REDELIVERED</code>.</p><p>Dynamically calculated delay from the
exchange<br clear="none"> In Camel 2.9 and 2.8.2: The header is
<strong>CamelRedeliveryDelay</strong>, which is also defined on the
<code>Exchange.REDELIVERY_DELAY</code>.<br clear="none"> Is this header is
absent, normal redelivery rules apply.</p><h4
id="BookInOnePage-Whichendpointfailed">Which endpoint
failed</h4><p><strong>Available as of Camel 2.1</strong></p><p>When Camel
routes messages it will decorate the <a shape="rect"
href="exchange.html">Exchange</a> with a property that contains the
<strong>last</strong> endpoint Camel send the <a shape="rect"
href="exchange.html">Exchange</a> to:</p><div class="code panel pdl"
style="border-width: 1px;">
+</div><h3 id="BookInOnePage-RedeliveryDefaultValues">Redelivery Default
Values</h3><p>Redelivery is disabled by default.</p><p>The default redeliver
policy will use the following
values:</p><ul><li><strong><code>maximumRedeliveries=0</code></strong></li><li><strong><code>redeliverDelay=1000L</code></strong>
(1 second)</li><li><strong><code>maximumRedeliveryDelay = 60 *
1000L</code></strong> (60
seconds)</li><li><strong><code>backOffMultiplier</code></strong> and
<strong><code>useExponentialBackOff</code></strong> are
ignored.</li><li><strong><code>retriesExhaustedLogLevel=LoggingLevel.ERROR</code></strong></li><li><strong><code>retryAttemptedLogLevel=LoggingLevel.DEBUG</code></strong></li><li>Stack
traces are logged for exhausted messages, from <strong>Camel
2.2</strong>.</li><li>Handled exceptions are not logged, from <strong>Camel
2.3</strong>.</li><li><strong><code>logExhaustedMessageHistory</code></strong>
is true for default error handler, and false for dead letter channel.</li
><li><strong><code>logExhaustedMessageBody</code></strong> <strong>Camel
>2.17:</strong> is disabled by default to avoid logging sensitive message
>body/header details. If this option is <strong><code>true</code></strong>,
>then <strong><code>logExhaustedMessageHistory</code></strong> must also
>be <strong><code>true</code></strong>.</li></ul><p>The maximum redeliver
>delay ensures that a delay is never longer than the value, default 1 minute.
>This can happen when
><strong><code>useExponentialBackOff=true</code></strong>.</p><p>The <strong><code>maximumRedeliveries</code></strong>
> is the number of <strong>re</strong>-delivery attempts. By default Camel
>will try to process the exchange 1 + 5 times. 1 time for the normal attempt
>and then 5 attempts as redeliveries.<br clear="none"> Setting
>the <strong><code>maximumRedeliveries=-1 </code></strong>(or
>< <strong><code>-1</code></strong>) will then always redelivery
>(unlimited).<br clear="none"> Setting the <str
ong><code>maximumRedeliveries=0</code></strong> will disable
re-delivery.</p><p>Camel will log delivery failures at
the <strong><code>DEBUG</code></strong> logging level by default. You can
change this by
specifying <strong><code>retriesExhaustedLogLevel</code></strong> and/or
<strong><code>retryAttemptedLogLevel</code></strong>. See <a shape="rect"
class="external-link"
href="http://svn.apache.org/repos/asf/camel/trunk/camel-core/src/test/java/org/apache/camel/builder/ExceptionBuilderWithRetryLoggingLevelSetTest.java";>ExceptionBuilderWithRetryLoggingLevelSetTest</a>
for an example.</p><p>You can turn logging of stack traces on/off. If turned
off Camel will still log the redelivery attempt. It's just much less
verbose.</p><h4 id="BookInOnePage-RedeliverDelayPattern">Redeliver Delay
Pattern</h4><p>Delay pattern is used as a single option to set a range pattern
for delays. When a delay pattern is in use the following options no longer
apply:</p><ul><li><strong><code>delay</c
ode></strong></li><li><strong><code>backOffMultiplier</code></strong></li><li><strong><code>useExponentialBackOff</code></strong></li><li><strong><code>useCollisionAvoidance</code></strong></li><li><strong><code>maximumRedeliveryDelay</code></strong></li></ul><p>The
idea is to set groups of ranges using the following syntax:
<strong><code>limit:delay;limit 2:delay 2;limit 3:delay 3;...;limit N:delay
N</code></strong></p><p>Each group has two values separated with colon:</p><ul
class="alternate"><li><strong><code>limit</code></strong> = upper
limit</li><li><strong><code>delay</code></strong> = delay in
milliseconds<br clear="none"> And the groups is again separated with
semi-colon. The rule of thumb is that the next groups should have a higher
limit than the previous group.</li></ul><p>Lets clarify this with an
example:<br clear="none">
<strong><code>delayPattern=5:1000;10:5000;20:20000</code></strong></p><p>That
gives us three groups:</p><ul class="alternate"><li><strong><code>
5:1000</code></strong></li><li><strong><code>10:5000</code></strong></li><li><strong><code>20:20000</code></strong></li></ul><p>Resulting
in these delays between redelivery attempts:</p><ul
class="alternate"><li>Redelivery attempt number <strong><code>1..4 =
0ms</code></strong> (as the first group start with 5)</li><li>Redelivery
attempt number <strong><code>5..9 = 1000ms</code></strong> (the first
group)</li><li>Redelivery attempt number <strong><code>10..19 =
5000ms</code></strong> (the second group)</li><li>Redelivery attempt
number <strong><code>20.. = 20000ms</code></strong> (the last
group)</li></ul><p>Note: The first redelivery attempt is
<strong><code>1</code></strong>, so the first group should start
with <strong><code>1</code></strong> or higher.</p><p>You can start a
group with limit <strong><code>1</code></strong> to e.g., have a starting
delay: <strong><code>delayPattern=1:1000;5:5000</code></strong></p><ul
class="alternate"><li>Redelivery
attempt number <strong><code>1..4 = 1000ms</code></strong> (the first
group)</li><li>Redelivery attempt number <strong><code>5.. =
5000ms</code></strong> (the last group)</li></ul><p>There is no requirement
that the next delay should be higher than the previous. You can use any delay
value you like. For example with
<strong><code>delayPattern=1:5000;3:1000</code></strong> we start with 5 sec
delay and then later reduce that to <strong><code>1</code></strong>
second.</p><h3 id="BookInOnePage-Redeliveryheader">Redelivery
header</h3><p>When a message is redelivered the <a shape="rect"
class="external-link"
href="http://camel.apache.org/maven/camel-core/apidocs/org/apache/camel/processor/DeadLetterChannel.html";>DeadLetterChannel</a>
will append a customizable header to the message to indicate how many times
its been redelivered. <br clear="none"> Before <strong>Camel 2.6</strong>: The
header is <strong><code>CamelRedeliveryCounter</code></strong>, which is also
defined on
the <strong><code>Exchange.REDELIVERY_COUNTER</code></strong>.<br
clear="none"> From <strong>Camel 2.6</strong>: The
header <strong><code>CamelRedeliveryMaxCounter</code></strong>, which is
also defined on the
<strong><code>Exchange.REDELIVERY_MAX_COUNTER</code></strong>, contains the
maximum redelivery setting. This header is absent if you use
<strong><code>retryWhile</code></strong> or have unlimited maximum redelivery
configured.</p><p>And a boolean flag whether it is being redelivered or not
(first attempt). The header <strong><code>CamelRedelivered</code></strong>
contains a boolean if the message is redelivered or not, which is also defined
on the <strong><code>Exchange.REDELIVERED</code></strong>.</p><h3
id="BookInOnePage-DynamicallyCalculatedDelayFromtheExchange">Dynamically
Calculated Delay From the Exchange</h3><p>In <strong>Camel 2.9</strong> and
<strong>2.8.2</strong>: The header
is <strong><code>CamelRedeliveryDelay</code></strong>, which is also
defined
on the <strong><code>Exchange.REDELIVERY_DELAY</code></strong>. If this
header is absent, normal redelivery rules apply.</p><h4
id="BookInOnePage-WhichEndpointFailed">Which Endpoint
Failed</h4><p><strong>Available as of Camel 2.1</strong></p><p>When Camel
routes messages it will decorate the <a shape="rect"
href="exchange.html">Exchange</a> with a property that contains the
<strong>last</strong> endpoint Camel send the <a shape="rect"
href="exchange.html">Exchange</a> to:</p><div class="code panel pdl"
style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter">String lastEndpointUri =
exchange.getProperty(Exchange.TO_ENDPOINT, String.class); </script>
</div>
-</div><p>The <code>Exchange.TO_ENDPOINT</code> have the constant value
<code>CamelToEndpoint</code>.</p><p>This information is updated when Camel
sends a message to any endpoint. So if it exists its the <strong>last</strong>
endpoint which Camel send the Exchange to.</p><p>When for example processing
the <a shape="rect" href="exchange.html">Exchange</a> at a given <a
shape="rect" href="endpoint.html">Endpoint</a> and the message is to be moved
into the dead letter queue, then Camel also decorates the Exchange with another
property that contains that <strong>last</strong> endpoint:</p><div class="code
panel pdl" style="border-width: 1px;">
+</div><p>The <strong><code>Exchange.TO_ENDPOINT</code></strong> have the
constant value <strong><code>CamelToEndpoint</code></strong>. This information
is updated when Camel sends a message to any endpoint. So if it exists its the
<strong>last</strong> endpoint which Camel send the Exchange to.</p><p>When for
example processing the <a shape="rect" href="exchange.html">Exchange</a> at a
given <a shape="rect" href="endpoint.html">Endpoint</a> and the message is to
be moved into the dead letter queue, then Camel also decorates the Exchange
with another property that contains that <strong>last</strong>
endpoint:</p><div class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter">String failedEndpointUri =
exchange.getProperty(Exchange.FAILURE_ENDPOINT, String.class); </script>
</div>
-</div><p>The <code>Exchange.FAILURE_ENDPOINT</code> have the constant value
<code>CamelFailureEndpoint</code>.</p><p>This allows for example you to fetch
this information in your dead letter queue and use that for error reporting.<br
clear="none"> This is useable if the Camel route is a bit dynamic such as the
dynamic <a shape="rect" href="recipient-list.html">Recipient List</a> so you
know which endpoints failed.</p><p><strong>Notice:</strong> These information
is kept on the Exchange even if the message was successfully processed by a
given endpoint, and then later fails for example in a local <a shape="rect"
href="bean.html">Bean</a> processing instead. So beware that this is a hint
that helps pinpoint errors.</p><div class="code panel pdl" style="border-width:
1px;">
+</div><p>The <strong><code>Exchange.FAILURE_ENDPOINT</code></strong> have the
constant value <strong><code>CamelFailureEndpoint</code></strong>.</p><p>This
allows for example you to fetch this information in your dead letter queue and
use that for error reporting. This is usable if the Camel route is a bit
dynamic such as the dynamic <a shape="rect"
href="recipient-list.html">Recipient List</a> so you know which endpoints
failed.</p><p><strong>Note:</strong> this information is retained on the
Exchange even if the message is subsequently processed successfully by a given
endpoint only to fail, for example, in local <a shape="rect"
href="bean.html">Bean</a> processing instead. So, beware that this is a hint
that helps pinpoint errors.</p><div class="code panel pdl" style="border-width:
1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter">from(&quot;activemq:queue:foo&quot;)
.to(&quot;http://someserver/somepath&quot;)
.beanRef(&quot;foo&quot;); </script>
</div>
-</div><p>Now suppose the route above and a failure happens in the
<code>foo</code> bean. Then the <code>Exchange.TO_ENDPOINT</code> and
<code>Exchange.FAILURE_ENDPOINT</code> will still contain the value of <code><a
shape="rect" class="external-link" href="http://someserver/somepath";
rel="nofollow">http://someserver/somepath</a></code>.</p><h3
id="BookInOnePage-OnPrepareFailure">OnPrepareFailure</h3><p><strong>Available
as of Camel 2.16</strong></p><p>Before the exchange is sent to the dead letter
queue, you can use onPrepare to allow a custom <code>Processor</code> to
prepare the exchange, such as adding information why the Exchange failed. For
example the following processor adds a header with the exception
message</p><div class="code panel pdl" style="border-width: 1px;">
+</div><p>Now suppose the route above and a failure happens in the
<code>foo</code> bean. Then the
<strong><code>Exchange.TO_ENDPOINT</code></strong> and
<strong><code>Exchange.FAILURE_ENDPOINT</code></strong> will still contain the
value of <code><a shape="rect" class="external-link"
href="http://someserver/somepath";
rel="nofollow">http://someserver/somepath</a></code>.</p><h3
id="BookInOnePage-OnPrepareFailure"><code>OnPrepareFailure</code></h3><p><strong>Available
as of Camel 2.16</strong></p><p>Before the exchange is sent to the dead letter
queue, you can use <strong><code>onPrepare</code></strong> to allow a
custom <strong><code>Processor</code></strong> to prepare the exchange,
such as adding information why the Exchange failed.</p><p>For example, the
following processor adds a header with the exception message:</p><div
class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter"> public static class MyPrepareProcessor implements
Processor { @Override public void process(Exchange exchange) throws Exception {
Exception cause = exchange.getProperty(Exchange.EXCEPTION_CAUGHT,
Exception.class); exchange.getIn().setHeader(&quot;FailedBecause&quot;,
cause.getMessage()); } }</script>
</div>
@@ -11884,15 +11884,15 @@ from("direct:start")
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter">errorHandler(deadLetterChannel(&quot;jms:dead&quot;).onPrepareFailure(new
MyPrepareProcessor()));</script>
</div>
-</div><p> </p><p>Configuring this from XML DSL is as shown:</p><div
class="code panel pdl" style="border-width: 1px;">
+</div><p> </p><p>Configuring this from XML DSL is as follows:</p><div
class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
- <script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter"> &lt;bean id=&quot;myPrepare&quot;
class=&quot;org.apache.camel.processor.DeadLetterChannelOnPrepareTest.MyPrepareProcessor&quot;/&gt;
&lt;errorHandler id=&quot;dlc&quot;
type=&quot;DeadLetterChannel&quot;
deadLetterUri=&quot;jms:dead&quot;
onPrepareFailureRef=&quot;myPrepare&quot;/&gt;</script>
+ <script class="brush: xml; gutter: false; theme: Default"
type="syntaxhighlighter">&lt;bean id=&quot;myPrepare&quot;
class=&quot;org.apache.camel.processor.DeadLetterChannelOnPrepareTest.MyPrepareProcessor&quot;/&gt;
&lt;errorHandler id=&quot;dlc&quot;
type=&quot;DeadLetterChannel&quot;
deadLetterUri=&quot;jms:dead&quot;
onPrepareFailureRef=&quot;myPrepare&quot;/&gt;</script>
</div>
-</div><p> </p><p>The onPrepare is also available using the default error
handler.</p><h3 id="BookInOnePage-Whichroutefailed">Which route
failed</h3><p><strong>Available as of Camel 2.10.4/2.11</strong></p><p>When
Camel error handler handles an error such as <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> or using <a
shape="rect" href="exception-clause.html">Exception Clause</a> with
handled=true, then Camel will decorate<br clear="none"> the <a shape="rect"
href="exchange.html">Exchange</a> with the route id where the error
occurred.</p><div class="code panel pdl" style="border-width: 1px;">
+</div><p> </p><p>The <strong><code>onPrepare</code></strong> is also
available using the default error handler.</p><h3
id="BookInOnePage-WhichRouteFailed">Which Route Failed</h3><p><strong>Available
as of Camel 2.10.4/2.11</strong></p><p>When Camel error handler handles an
error such as <a shape="rect" href="dead-letter-channel.html">Dead Letter
Channel</a> or using <a shape="rect" href="exception-clause.html">Exception
Clause</a> with <strong><code>handled=true</code></strong>, then Camel will
decorate the <a shape="rect" href="exchange.html">Exchange</a> with the route
id where the error occurred.</p><p>Example:</p><div class="code panel pdl"
style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter">String failedRouteId =
exchange.getProperty(Exchange.FAILURE_ROUTE_ID, String.class); </script>
</div>
-</div><p>The <code>Exchange.FAILURE_ROUTE_ID</code> have the constant value
<code>CamelFailureRouteId</code>.</p><p>This allows for example you to fetch
this information in your dead letter queue and use that for error
reporting.</p><h3
id="BookInOnePage-Controlifredeliveryisallowedduringstopping/shutdown">Control
if redelivery is allowed during stopping/shutdown</h3><p><strong>Available as
of Camel 2.11</strong></p><p>Prior to Camel 2.10, Camel will perform redelivery
while stopping a route, or shutting down Camel. This has improved a bit in
Camel 2.10 onwards, as Camel will not perform redelivery attempts when shutting
down aggressively (eg during <a shape="rect"
href="graceful-shutdown.html">Graceful Shutdown</a> and timeout hit). From
Camel 2.11 onwards there is a new option
<code>allowRedeliveryWhileStopping</code> which you can use to control if
redelivery is allowed or not; notice that any in progress redelivery will still
be executed. This option can only disallow any redeli
very to be executed <strong>after</strong> the stopping of a route/shutdown of
Camel has been triggered. If a redelivery is dissallowed then a
<code>RejectedExcutionException</code> is set on the <a shape="rect"
href="exchange.html">Exchange</a> and the processing of the <a shape="rect"
href="exchange.html">Exchange</a> stops. This means any consumer will see the
<a shape="rect" href="exchange.html">Exchange</a> as failed due the
<code>RejectedExecutionException</code>.</p><p>The default value is
<code>true</code> to be backwards compatible as before. For example the
following sample shows how to do this with Java DSL and XML DSL
+</div><p>The <strong><code>Exchange.FAILURE_ROUTE_ID</code></strong> have the
constant value <strong><code>CamelFailureRouteId</code></strong>. This allows
for example you to fetch this information in your dead letter queue and use
that for error reporting.</p><h3
id="BookInOnePage-ControlifRedeliveryisAllowedDuringStopping/Shutdown">Control
if Redelivery is Allowed During Stopping/Shutdown</h3><p><strong>Available as
of Camel 2.11</strong></p><p>Before <strong>Camel 2.10</strong>, Camel would
perform redelivery while stopping a route, or shutting down Camel. This has
improved a bit in <strong>Camel 2.10</strong>: Camel will no longer perform
redelivery attempts when shutting down aggressively, e.g., during <a
shape="rect" href="graceful-shutdown.html">Graceful Shutdown</a> and timeout
hit.</p><p>From <strong>Camel 2.11</strong>: there is a new option
<strong><code>allowRedeliveryWhileStopping</code></strong> which you can use to
control if redelivery is allowed or not; notice that
any in progress redelivery will still be executed. This option can only
disallow any redelivery to be executed <em><strong>after</strong></em> the
stopping of a route/shutdown of Camel has been triggered. If a redelivery is
disallowed then a <strong><code>RejectedExcutionException</code></strong> is
set on the <a shape="rect" href="exchange.html">Exchange</a> and the processing
of the <a shape="rect" href="exchange.html">Exchange</a> stops. This means any
consumer will see the <a shape="rect" href="exchange.html">Exchange</a> as
failed due the <strong><code>RejectedExcutionException</code></strong>. The
default value is <strong><code>true</code></strong> for backward
compatibility.</p><p>For example, the following snippet shows how to do this
with Java DSL and XML DSL:
</p><div class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter"> // this error handler will try up till 20 redelivery
attempts with 1 second between. // however if we are stopping then do not allow
any redeliver attempts. errorHandler(defaultErrorHandler()
.allowRedeliveryWhileStopping(false)
.maximumRedeliveries(20).redeliveryDelay(1000).retryAttemptedLogLevel(LoggingLevel.INFO));
from(&quot;seda:foo&quot;).routeId(&quot;foo&quot;)
.to(&quot;mock:foo&quot;) .throwException(new
IllegalArgumentException(&quot;Forced&quot;)); </script>
@@ -11912,17 +11912,17 @@ from("direct:start")
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter"> RouteBuilder builder = new RouteBuilder() { public
void configure() { // configures dead letter channel to use seda queue for
errors and use at most 2 redelveries // and exponential backoff
errorHandler(deadLetterChannel(&quot;seda:errors&quot;).maximumRedeliveries(2).useExponentialBackOff());
// here is our route
from(&quot;seda:a&quot;).to(&quot;seda:b&quot;); } }; </script>
</div>
- </div><h3 id="BookInOnePage-HowcanImodifytheExchangebeforeredelivery?">How
can I modify the Exchange before redelivery?</h3><p>We support directly in <a
shape="rect" href="dead-letter-channel.html">Dead Letter Channel</a> to set a
<a shape="rect" href="processor.html">Processor</a> that is executed
<strong>before</strong> each redelivery attempt.</p><p>When <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> is doing redeliver its
possible to configure a <a shape="rect" href="processor.html">Processor</a>
that is executed just <strong>before</strong> every redelivery attempt. This
can be used for the situations where you need to alter the message before its
redelivered.</p><p>Here we configure the <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> to use our processor
<code>MyRedeliveryProcessor</code> to be executed before each redelivery.
+ </div><h3 id="BookInOnePage-HowCanIModifytheExchangeBeforeRedelivery?">How
Can I Modify the Exchange Before Redelivery?</h3><p>We support directly in <a
shape="rect" href="dead-letter-channel.html">Dead Letter Channel</a> to set a
<a shape="rect" href="processor.html">Processor</a> that is executed
<strong>before</strong> each redelivery attempt. When <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> is doing redeliver its
possible to configure a <a shape="rect" href="processor.html">Processor</a>
that is executed just <strong>before</strong> every redelivery attempt. This
can be used for the situations where you need to alter the message before its
redelivered. Here we configure the <a shape="rect"
href="dead-letter-channel.html">Dead Letter Channel</a> to use our processor
<strong><code>MyRedeliveryProcessor</code></strong> to be executed before each
redelivery.
</p><div class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter"> // we configure our Dead Letter Channel to invoke //
MyRedeliveryProcessor before a redelivery is // attempted. This allows us to
alter the message before
errorHandler(deadLetterChannel(&quot;mock:error&quot;).maximumRedeliveries(5)
.onRedelivery(new MyRedeliverProcessor()) // setting delay to zero is just to
make unit testing faster .redeliveryDelay(0L)); </script>
</div>
- </div>And this is the processor <code>MyRedeliveryProcessor</code> where we
alter the message.
+ </div>And this is the processor
<strong><code>MyRedeliveryProcessor</code></strong> where we alter the message.
<div class="code panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter"> // This is our processor that is executed before
every redelivery attempt // here we can do what we want in the java code, such
as altering the message public class MyRedeliverProcessor implements Processor
{ public void process(Exchange exchange) throws Exception { // the message is
being redelivered so we can alter it // we just append the redelivery counter
to the body // you can of course do all kind of stuff instead String body =
exchange.getIn().getBody(String.class); int count =
exchange.getIn().getHeader(Exchange.REDELIVERY_COUNTER, Integer.class);
exchange.getIn().setBody(body + count); // the maximum redelivery was set to 5
int max = exchange.getIn().getHeader(Exchange.REDELIVERY_MAX_COUNTER,
Integer.class); assertEquals(5, max); } } </script>
</div>
- </div><h3
id="BookInOnePage-HowcanIlogwhatcausedtheDeadLetterChanneltobeinvoked?">How can
I log what caused the Dead Letter Channel to be invoked?</h3><p>You often need
to know what went wrong that caused the Dead Letter Channel to be used and it
does not offer logging for this purpose. So the Dead Letter Channel's endpoint
can be set to a endpoint of our own (such
as <code>direct:deadLetterChannel</code>). We write a route to accept this
Exchange and log the Exception, then forward on to where we want the failed
Exchange moved to (which might be a DLQ queue for instance). See also <a
shape="rect" class="external-link"
href="http://stackoverflow.com/questions/13711462/logging-camel-exceptions-and-sending-to-the-dead-letter-channel";
rel="nofollow">http://stackoverflow.com/questions/13711462/logging-camel-exceptions-and-sending-to-the-dead-letter-channel</a></p><p></p><h4
id="BookInOnePage-UsingThisPattern.8">Using This Pattern</h4> <p>If you would
like to use this EIP Patt
ern then please read the <a shape="rect" href="getting-started.html">Getting
Started</a>, you may also find the <a shape="rect"
href="architecture.html">Architecture</a> useful particularly the description
of <a shape="rect" href="endpoint.html">Endpoint</a> and <a shape="rect"
href="uris.html">URIs</a>. Then you could try out some of the <a shape="rect"
href="examples.html">Examples</a> first before trying this pattern out.</p><ul
class="alternate"><li><a shape="rect" href="error-handler.html">Error
Handler</a></li><li><a shape="rect" href="exception-clause.html">Exception
Clause</a></li></ul><h3 id="BookInOnePage-GuaranteedDelivery">Guaranteed
Delivery</h3><p>Camel supports the <a shape="rect" class="external-link"
href="http://www.enterpriseintegrationpatterns.com/GuaranteedMessaging.html";
rel="nofollow">Guaranteed Delivery</a> from the <a shape="rect"
href="enterprise-integration-patterns.html">EIP patterns</a> using among others
the following components:</p><ul><li><a shape="re
ct" href="file2.html">File</a> for using file systems as a persistent store of
messages</li><li><a shape="rect" href="jms.html">JMS</a> when using persistent
delivery (the default) for working with JMS Queues and Topics for high
performance, clustering and load balancing</li><li><a shape="rect"
href="jpa.html">JPA</a> for using a database as a persistence layer, or use any
of the many other database component such as <a shape="rect"
href="sql.html">SQL</a>, <a shape="rect" href="jdbc.html">JDBC</a>, <a
shape="rect" href="ibatis.html">iBATIS</a>/<a shape="rect"
href="mybatis.html">MyBatis</a>, <a shape="rect"
href="hibernate.html">Hibernate</a></li><li><a shape="rect"
href="hawtdb.html">HawtDB</a> for a lightweight key-value persistent
store</li></ul><p><span class="confluence-embedded-file-wrapper"><img
class="confluence-embedded-image confluence-external-resource"
src="http://www.enterpriseintegrationpatterns.com/img/GuaranteedMessagingSolution.gif";
data-image-src="http://www.enter
priseintegrationpatterns.com/img/GuaranteedMessagingSolution.gif"></span></p><h4
id="BookInOnePage-Example.7">Example</h4><p>The following example demonstrates
illustrates the use of <a shape="rect" class="external-link"
href="http://www.enterpriseintegrationpatterns.com/GuaranteedMessaging.html";
rel="nofollow">Guaranteed Delivery</a> within the <a shape="rect"
href="jms.html">JMS</a> component. By default, a message is not considered
successfully delivered until the recipient has persisted the message locally
guaranteeing its receipt in the event the destination becomes
unavailable.</p><p><strong>Using the <a shape="rect"
href="fluent-builders.html">Fluent Builders</a></strong></p><div class="code
panel pdl" style="border-width: 1px;">
+ </div><h3
id="BookInOnePage-HowCanILogWhatCausedtheDeadLetterChanneltobeInvoked?">How Can
I Log What Caused the Dead Letter Channel to be Invoked?</h3><p>You often need
to know what went wrong that caused the Dead Letter Channel to be used and it
does not offer logging for this purpose. So the Dead Letter Channel's endpoint
can be set to a endpoint of our own (such
as <strong><code>direct:deadLetterChannel</code></strong>). We write a
route to accept this Exchange and log the Exception, then forward on to where
we want the failed Exchange moved to (which might be a DLQ queue for instance).
See also <a shape="rect" class="external-link"
href="http://stackoverflow.com/questions/13711462/logging-camel-exceptions-and-sending-to-the-dead-letter-channel";
rel="nofollow">http://stackoverflow.com/questions/13711462/logging-camel-exceptions-and-sending-to-the-dead-letter-channel</a></p><p></p><h4
id="BookInOnePage-UsingThisPattern.8">Using This Pattern</h4> <p>If you would
like to
use this EIP Pattern then please read the <a shape="rect"
href="getting-started.html">Getting Started</a>, you may also find the <a
shape="rect" href="architecture.html">Architecture</a> useful particularly the
description of <a shape="rect" href="endpoint.html">Endpoint</a> and <a
shape="rect" href="uris.html">URIs</a>. Then you could try out some of the <a
shape="rect" href="examples.html">Examples</a> first before trying this pattern
out.</p><ul class="alternate"><li><a shape="rect"
href="error-handler.html">Error Handler</a></li><li><a shape="rect"
href="exception-clause.html">Exception Clause</a></li></ul><h3
id="BookInOnePage-GuaranteedDelivery">Guaranteed Delivery</h3><p>Camel supports
the <a shape="rect" class="external-link"
href="http://www.enterpriseintegrationpatterns.com/GuaranteedMessaging.html";
rel="nofollow">Guaranteed Delivery</a> from the <a shape="rect"
href="enterprise-integration-patterns.html">EIP patterns</a> using among others
the following components:</p><ul
><li><a shape="rect" href="file2.html">File</a> for using file systems as a
>persistent store of messages</li><li><a shape="rect" href="jms.html">JMS</a>
>when using persistent delivery (the default) for working with JMS Queues and
>Topics for high performance, clustering and load balancing</li><li><a
>shape="rect" href="jpa.html">JPA</a> for using a database as a persistence
>layer, or use any of the many other database component such as <a
>shape="rect" href="sql.html">SQL</a>, <a shape="rect"
>href="jdbc.html">JDBC</a>, <a shape="rect" href="ibatis.html">iBATIS</a>/<a
>shape="rect" href="mybatis.html">MyBatis</a>, <a shape="rect"
>href="hibernate.html">Hibernate</a></li><li><a shape="rect"
>href="hawtdb.html">HawtDB</a> for a lightweight key-value persistent
>store</li></ul><p><span class="confluence-embedded-file-wrapper"><img
>class="confluence-embedded-image confluence-external-resource"
>src="http://www.enterpriseintegrationpatterns.com/img/GuaranteedMessagingSolution.gif";
> data-image-src=
"http://www.enterpriseintegrationpatterns.com/img/GuaranteedMessagingSolution.gif";></span></p><h4
id="BookInOnePage-Example.7">Example</h4><p>The following example demonstrates
illustrates the use of <a shape="rect" class="external-link"
href="http://www.enterpriseintegrationpatterns.com/GuaranteedMessaging.html";
rel="nofollow">Guaranteed Delivery</a> within the <a shape="rect"
href="jms.html">JMS</a> component. By default, a message is not considered
successfully delivered until the recipient has persisted the message locally
guaranteeing its receipt in the event the destination becomes
unavailable.</p><p><strong>Using the <a shape="rect"
href="fluent-builders.html">Fluent Builders</a></strong></p><div class="code
panel pdl" style="border-width: 1px;">
<div class="codeContent panelContent pdl">
<script class="brush: java; gutter: false; theme: Default"
type="syntaxhighlighter">from(&quot;direct:start&quot;)
.to(&quot;jms:queue:foo&quot;);</script>
</div>
@@ -14234,8 +14234,8 @@ cometds://localhost:8443/service/mychann
<div class="confluence-information-macro-body">
<p>When using CXF in streaming modes (see DataFormat option), then also read
about <a shape="rect" href="stream-caching.html">Stream caching</a>.</p>
</div>
-</div><p>The <strong>cxf:</strong> component provides integration with <a
shape="rect" href="http://cxf.apache.org";>Apache CXF</a> for connecting to
JAX-WS services hosted in CXF.</p><p><style type="text/css">/**/
div.rbtoc1485983970754 {padding: 0px;} div.rbtoc1485983970754 ul {list-style:
disc;margin-left: 0px;} div.rbtoc1485983970754 li {margin-left:
0px;padding-left: 0px;} /**/</style>
- </p><div class="toc-macro rbtoc1485983970754">
+</div><p>The <strong>cxf:</strong> component provides integration with <a
shape="rect" href="http://cxf.apache.org";>Apache CXF</a> for connecting to
JAX-WS services hosted in CXF.</p><p><style type="text/css">/**/
div.rbtoc1486171111973 {padding: 0px;} div.rbtoc1486171111973 ul {list-style:
disc;margin-left: 0px;} div.rbtoc1486171111973 li {margin-left:
0px;padding-left: 0px;} /**/</style>
+ </p><div class="toc-macro rbtoc1486171111973">
<ul class="toc-indentation"><li><a shape="rect"
href="#BookInOnePage-CXFComponent">CXF Component</a>
<ul class="toc-indentation"><li><a shape="rect"
href="#BookInOnePage-URIformat">URI format</a></li><li><a shape="rect"
href="#BookInOnePage-Options">Options</a>
<ul class="toc-indentation"><li><a shape="rect"
href="#BookInOnePage-Thedescriptionsofthedataformats">The descriptions of the
dataformats</a>
![http://www.enterpriseintegrationpatterns.com/img/DeadLetterChannelSolution.gif"](http://www.enterpriseintegrationpatterns.com/img/DeadLetterChannelSolution.gif"){kind=link}
![http://www.enterpriseintegrationpatterns.com/img/GuaranteedMessagingSolution.gif"](http://www.enterpriseintegrationpatterns.com/img/GuaranteedMessagingSolution.gif"){kind=link}