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Posted to commits@camel.apache.org by bu...@apache.org on 2014/10/21 10:18:24 UTC
svn commit: r926300 - in /websites/production/camel/content:
cache/main.pageCache try-catch-finally.html
Author: buildbot
Date: Tue Oct 21 08:18:24 2014
New Revision: 926300
Log:
Production update by buildbot for camel
Modified:
websites/production/camel/content/cache/main.pageCache
websites/production/camel/content/try-catch-finally.html
Modified: websites/production/camel/content/cache/main.pageCache
==============================================================================
Binary files - no diff available.
Modified: websites/production/camel/content/try-catch-finally.html
==============================================================================
--- websites/production/camel/content/try-catch-finally.html (original)
+++ websites/production/camel/content/try-catch-finally.html Tue Oct 21 08:18:24 2014
@@ -86,41 +86,26 @@
<tbody>
<tr>
<td valign="top" width="100%">
-<div class="wiki-content maincontent"><h2 id="TryCatchFinally-Try...Catch...Finally">Try ... Catch ... Finally</h2>
-<p>Camel supports the Java equivalent of try .. catch and finally directly in the DSL.<br clear="none">
-It aims to work like its Java sisters but with more power. Especially in Camel 2.0 where we gave this feature an overhaul.</p>
-
-<p>In Camel we prefix the keywords with <code>do</code> to avoid having same keyword as Java. So we have:</p>
-<ul class="alternate"><li><code>doTry</code></li><li><code>doCatch</code></li><li><code>doFinally</code></li><li><code>end</code> to end the block in Java DSL</li></ul>
-
-
-<p>Notice this document is based on how it works in Camel 2.0. In Camel 1.x this feature isn't as powerful and it uses a slight different keyword names.</p>
-
- <div class="aui-message hint shadowed information-macro">
+<div class="wiki-content maincontent"><h2 id="TryCatchFinally-Try...Catch...Finally">Try ... Catch ... Finally</h2><p>Camel supports the Java equivalent of try .. catch and finally directly in the DSL.<br clear="none"> It aims to work like its Java sisters but with more power. Especially in Camel 2.0 where we gave this feature an overhaul.</p><p>In Camel we prefix the keywords with <code>do</code> to avoid having same keyword as Java. So we have:</p><ul class="alternate"><li><code>doTry</code></li><li><code>doCatch</code></li><li><code>doFinally</code></li><li><code>end</code> to end the block in Java DSL</li></ul><p>Notice this document is based on how it works in Camel 2.0. In Camel 1.x this feature isn't as powerful and it uses a slight different keyword names.</p> <div class="aui-message hint shadowed information-macro">
<p class="title">Camel error handling is disabled</p>
<span class="aui-icon icon-hint">Icon</span>
<div class="message-content">
-
-<p>When using <code>doTry .. doCatch .. doFinally</code> then the regular Camel <a shape="rect" href="error-handler.html">Error Handler</a> does not apply. That means any <code>onException</code> or the likes does not trigger. The reason is that <code>doTry .. doCatch .. doFinally</code> is in fact its own error handler and that it aims to mimic and work like how try/catch/finally works in Java.</p>
+ <p>When using <code>doTry .. doCatch .. doFinally</code> then the regular Camel <a shape="rect" href="error-handler.html">Error Handler</a> does not apply. That means any <code>onException</code> or the likes does not trigger. The reason is that <code>doTry .. doCatch .. doFinally</code> is in fact its own error handler and that it aims to mimic and work like how try/catch/finally works in Java.</p>
</div>
</div>
-
-
-<h3 id="TryCatchFinally-AboutdoCatchanditspoweroverJava">About <code>doCatch</code> and its power over Java</h3>
-<p>The <code>doCatch</code> in Camel is empowered over its Java sister.</p>
-
-<p>First of all you can define multiple exceptions to catch in a single block.</p>
-
-<p>And second of all an important aspect over the regular Java counter parts is that Camel will check in the exception hierarchy when it matches a thrown exception against the <code>doCatch</code> blocks. The reasons is that many times the original caused exceptions is wrapped by other wrapper exceptions, typically transposing the exception from a checked to a runtime exception.<br clear="none">
-Camel for instance does this by wrapped it in a <code>CamelRuntimeException</code>. So if the original caused exception is an <code>java.io.IOException</code> then Camel will still match a <code>doCatch</code> block defined with an <code>java.io.IOException</code>. And just like Java the order in which you have multiple <code>doCatch</code> blocks matter. Camel will iterate from the top going down and use the first <code>doCatch</code> that matches the exception. The reason is to keep it similar to the regular java and how it selects a catch block. This differers from the <a shape="rect" href="exception-clause.html">Exception Clause</a> that has a more intelligent exception selection strategy among multiple <code>onException</code> definitions, where it also consider the delta in the exception hierarchy to select the best definition.</p>
-
-<p>A third feature is that you can attach a <code>onWhen</code> predicate to signal if the catch should trigger or not at runtime.</p>
-
-<p>And to simulate <em>rethrowing</em> an exception from a <code>doCatch</code> you should use the <code>handled</code> predicate. If its evaluated to <code>false</code> Camel will reattach the exception on the <a shape="rect" href="exchange.html">Exchange</a>. </p>
-
-<h3 id="TryCatchFinally-Usingtry..catch..finallyinJavaDSL">Using try .. catch .. finally in Java DSL</h3>
-<p>In the route below we have all keywords in action. As the code is based on a unit test we route using <a shape="rect" href="mock.html">Mock</a>.</p>
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<h3 id="TryCatchFinally-doTryaroundaContentBasedRouternotsupported"><code>doTry</code> around a Content Based Router not supported</h3><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[from("direct:dotry").setExchangePattern(ExchangePattern.InOut)
+ .doTry()
+ .to("https://localhost:8080/rest/order/123")
+ .choice()
+ .when().simple("${header.CamelHttpResponseCode} == '200'")
+ .convertBodyTo(String.class)
+ // DO SOMETHING
+ .endChoice()
+ .doCatch(Exception.class) // NOT SUPPORTED !!
+ .log(">> Exception")
+ .endDoTry();]]></script>
+</div></div><p><span style="color: rgb(34,34,34);"><br clear="none"></span></p><p><span style="color: rgb(34,34,34);">The ChoiceDefinition class which is part of the DSL language of Apache Camel to implement the Content Based Router EIP Pattern doesn’t extends the OutputDefinition, which means that you cannot define the doCatch after the ChoiceDefinition as presented with the previous example. </span><span style="color: rgb(34,34,34);">If you want to catch the exception inside of ChoiceDefinition, you can use error handler or use doTry…doCatch inside of when part.</span></p><h3 id="TryCatchFinally-AboutdoCatchanditspoweroverJava">About <code>doCatch</code> and its power over Java</h3><p>The <code>doCatch</code> in Camel is empowered over its Java sister.</p><p>First of all you can define multiple exceptions to catch in a single block.</p><p>And second of all an important aspect over the regular Java counter parts is that Camel will check in the exception hierarchy w
hen it matches a thrown exception against the <code>doCatch</code> blocks. The reasons is that many times the original caused exceptions is wrapped by other wrapper exceptions, typically transposing the exception from a checked to a runtime exception.<br clear="none"> Camel for instance does this by wrapped it in a <code>CamelRuntimeException</code>. So if the original caused exception is an <code>java.io.IOException</code> then Camel will still match a <code>doCatch</code> block defined with an <code>java.io.IOException</code>. And just like Java the order in which you have multiple <code>doCatch</code> blocks matter. Camel will iterate from the top going down and use the first <code>doCatch</code> that matches the exception. The reason is to keep it similar to the regular java and how it selects a catch block. This differers from the <a shape="rect" href="exception-clause.html">Exception Clause</a> that has a more intelligent exception selection strategy among multiple <code>onExc
eption</code> definitions, where it also consider the delta in the exception hierarchy to select the best definition.</p><p>A third feature is that you can attach a <code>onWhen</code> predicate to signal if the catch should trigger or not at runtime.</p><p>And to simulate <em>rethrowing</em> an exception from a <code>doCatch</code> you should use the <code>handled</code> predicate. If its evaluated to <code>false</code> Camel will reattach the exception on the <a shape="rect" href="exchange.html">Exchange</a>.</p><h3 id="TryCatchFinally-Usingtry..catch..finallyinJavaDSL">Using try .. catch .. finally in Java DSL</h3><p>In the route below we have all keywords in action. As the code is based on a unit test we route using <a shape="rect" href="mock.html">Mock</a>.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
from("direct:start")
.doTry()
@@ -132,11 +117,7 @@ from("direct:start")
.to("mock:finally")
.end();
]]></script>
-</div></div>
-
-<p>And in the route below we want to indicate if an IOException occured we want to route it elsewhere and at the same time keep the exception so the original caller is notified about this exception. To do this we need to not <em>rethrow</em> the exception and this is why we use <strong>handled</strong> and set it to false to indicate, no we did not handle it so please keep the exception.<br clear="none">
-The 2nd exception block can be omitted but as the code is based on an unit test we want to test the behavior non <code>IOException</code> as well.</p>
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+</div></div><p>And in the route below we want to indicate if an IOException occured we want to route it elsewhere and at the same time keep the exception so the original caller is notified about this exception. To do this we need to not <em>rethrow</em> the exception and this is why we use <strong>handled</strong> and set it to false to indicate, no we did not handle it so please keep the exception.<br clear="none"> The 2nd exception block can be omitted but as the code is based on an unit test we want to test the behavior non <code>IOException</code> as well.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
from("direct:start")
// here is our try where we try processing the exchange in the route below if it fails
@@ -156,11 +137,7 @@ from("direct:start")
// here the try block ends
.end();
]]></script>
-</div></div>
-
-<p>And finally we have an example of the <code>onWhen</code> predicate in action. We can attach it to a <code>doCatch</code> block and at runtime determine if the block should be triggered or not.<br clear="none">
-In our case we only want to trigger if the caused exception message contains the <strong>damn</strong> word.</p>
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+</div></div><p>And finally we have an example of the <code>onWhen</code> predicate in action. We can attach it to a <code>doCatch</code> block and at runtime determine if the block should be triggered or not.<br clear="none"> In our case we only want to trigger if the caused exception message contains the <strong>damn</strong> word.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
from("direct:start")
// here is our try where we try processing the exchange in the route below if it fails
@@ -183,23 +160,14 @@ from("direct:start")
// here the try block ends
.end();
]]></script>
-</div></div>
-
- <div class="aui-message success shadowed information-macro">
+</div></div> <div class="aui-message success shadowed information-macro">
<p class="title">Use end() to end the block</p>
<span class="aui-icon icon-success">Icon</span>
<div class="message-content">
-
-<p>Notice when using Java DSL we must use <code>end()</code> to indicate where the try .. catch .. finally block ends. As the example above has a finally, then the <code>end()</code> should be at the end of the finally block. If we are not using a finally, then the <code>end()</code> should be at the end of the <code>doCatch</code> to indicate the end there.</p>
+ <p>Notice when using Java DSL we must use <code>end()</code> to indicate where the try .. catch .. finally block ends. As the example above has a finally, then the <code>end()</code> should be at the end of the finally block. If we are not using a finally, then the <code>end()</code> should be at the end of the <code>doCatch</code> to indicate the end there.</p>
</div>
</div>
-
-
-<h3 id="TryCatchFinally-Usingtry..catch..finallyinSpringDSL">Using try .. catch .. finally in Spring DSL</h3>
-<p>We show the three sample samples using Spring DSL instead.</p>
-
-<p>In the route below we have all keywords in action. As the code is based on a unit test we route using <a shape="rect" href="mock.html">Mock</a>.</p>
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<h3 id="TryCatchFinally-Usingtry..catch..finallyinSpringDSL">Using try .. catch .. finally in Spring DSL</h3><p>We show the three sample samples using Spring DSL instead.</p><p>In the route below we have all keywords in action. As the code is based on a unit test we route using <a shape="rect" href="mock.html">Mock</a>.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
<script class="theme: Default; brush: xml; gutter: false" type="syntaxhighlighter"><![CDATA[
<route>
<from uri="direct:start"/>
@@ -219,11 +187,7 @@ from("direct:start")
</doTry>
</route>
]]></script>
-</div></div>
-
-<p>And in the route below we want to indicate if an IOException occured we want to route it elsewhere and at the same time keep the exception so the original caller is notified about this exception. To do this we need to not <em>rethrow</em> the exception and this is why we use <strong>handled</strong> and set it to false to indicate, no we did not handle it so please keep the exception.<br clear="none">
-The 2nd exception block can be omitted but as the code is based on an unit test we want to test the behavior non <code>IOException</code> as well.</p>
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+</div></div><p>And in the route below we want to indicate if an IOException occured we want to route it elsewhere and at the same time keep the exception so the original caller is notified about this exception. To do this we need to not <em>rethrow</em> the exception and this is why we use <strong>handled</strong> and set it to false to indicate, no we did not handle it so please keep the exception.<br clear="none"> The 2nd exception block can be omitted but as the code is based on an unit test we want to test the behavior non <code>IOException</code> as well.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
<script class="theme: Default; brush: xml; gutter: false" type="syntaxhighlighter"><![CDATA[
<route>
<from uri="direct:start"/>
@@ -248,11 +212,7 @@ The 2nd exception block can be omitted b
</doTry>
</route>
]]></script>
-</div></div>
-
-<p>And finally we have an example of the <code>onWhen</code> predicate in action. We can attach it to a <code>doCatch</code> block and at runtime determine if the block should be triggered or not.<br clear="none">
-In our case we only want to trigger if the caused exception message contains the <strong>damn</strong> word.</p>
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+</div></div><p>And finally we have an example of the <code>onWhen</code> predicate in action. We can attach it to a <code>doCatch</code> block and at runtime determine if the block should be triggered or not.<br clear="none"> In our case we only want to trigger if the caused exception message contains the <strong>damn</strong> word.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
<script class="theme: Default; brush: xml; gutter: false" type="syntaxhighlighter"><![CDATA[
<route>
<from uri="direct:start"/>
@@ -282,11 +242,7 @@ In our case we only want to trigger if t
</doTry>
</route>
]]></script>
-</div></div>
-
-<h3 id="TryCatchFinally-SeeAlso">See Also</h3>
-<ul class="alternate"><li><a shape="rect" href="error-handling-in-camel.html">Error handling in Camel</a></li><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>
-</div>
+</div></div><h3 id="TryCatchFinally-SeeAlso">See Also</h3><ul class="alternate"><li><a shape="rect" href="error-handling-in-camel.html">Error handling in Camel</a></li><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></div>
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