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Posted to commits@servicemix.apache.org by ch...@apache.org on 2007/01/05 21:05:14 UTC
svn commit: r493167 - /incubator/servicemix/site/beanflow.html
Author: chirino
Date: Fri Jan 5 12:05:13 2007
New Revision: 493167
URL: http://svn.apache.org/viewvc?view=rev&rev=493167
Log:
Latest export from confluence
Modified:
incubator/servicemix/site/beanflow.html
Modified: incubator/servicemix/site/beanflow.html
URL: http://svn.apache.org/viewvc/incubator/servicemix/site/beanflow.html?view=diff&rev=493167&r1=493166&r2=493167
==============================================================================
--- incubator/servicemix/site/beanflow.html (original)
+++ incubator/servicemix/site/beanflow.html Fri Jan 5 12:05:13 2007
@@ -147,7 +147,7 @@
<UL>
<LI><SPAN class="nobr"><A href="http://incubator.apache.org/servicemix/maven/servicemix-beanflow/apidocs/" title="Visit page outside Confluence" rel="nofollow">BeanFlow JavaDoc<SUP><IMG class="rendericon" src="http://goopen.org/confluence/images/icons/linkext7.gif" height="0" width="0" align="absmiddle" alt="" border="0"></SUP></A></SPAN></LI>
<LI><A href="beanflow-patterns.html" title="BeanFlow Patterns">BeanFlow Patterns</A></LI>
- <LI><SPAN class="nobr"><A href="https://svn.apache.org/repos/asf/incubator/servicemix/trunk/servicemix-beanflow/" title="Visit page outside Confluence" rel="nofollow">BeanFlow Source Code<SUP><IMG class="rendericon" src="http://goopen.org/confluence/images/icons/linkext7.gif" height="0" width="0" align="absmiddle" alt="" border="0"></SUP></A></SPAN></LI>
+ <LI><SPAN class="nobr"><A href="http://svn.apache.org/repos/asf/incubator/servicemix/trunk/common/servicemix-beanflow/" title="Visit page outside Confluence" rel="nofollow">BeanFlow Source Code<SUP><IMG class="rendericon" src="http://goopen.org/confluence/images/icons/linkext7.gif" height="0" width="0" align="absmiddle" alt="" border="0"></SUP></A></SPAN></LI>
</UL>
@@ -248,7 +248,21 @@
<P>Here is an example of performing joins using collections of child workflows</P>
+<DIV class="code"><DIV class="codeContent">
+<PRE class="code-java"><SPAN class="code-comment">// lets create a join on a number of child flows completing
+</SPAN>JoinAll flow = <SPAN class="code-keyword">new</SPAN> JoinAll(child1, child2, child3);
+flow.startWithTimeout(timer, timeout);
+
+<SPAN class="code-comment">// now lets test the flow
+</SPAN>child1.stop();
+assertStarted(flow);
+
+child2.stop();
+assertStarted(flow);
+child3.stop();
+assertStopped(flow);</PRE>
+</DIV></DIV>
<H3><A name="BeanFlow-Joinconditions"></A>Join conditions</H3>
@@ -272,7 +286,36 @@
<P>Here is an example activity implemented in Java code for the above code.</P>
+<DIV class="code"><DIV class="codeContent">
+<PRE class="code-java"><SPAN class="code-comment">// lets create some child workflows
+</SPAN><SPAN class="code-keyword">final</SPAN> Activity a = <SPAN class="code-keyword">new</SPAN> TimeoutActivity();
+<SPAN class="code-keyword">final</SPAN> Activity b = <SPAN class="code-keyword">new</SPAN> TimeoutActivity();
+<SPAN class="code-keyword">final</SPAN> Activity c = <SPAN class="code-keyword">new</SPAN> TimeoutActivity();
+
+<SPAN class="code-comment">// lets create the activity with a custom join condition
+</SPAN>Activity activity = <SPAN class="code-keyword">new</SPAN> JoinSupport(a, b, c) {
+ @Override
+ <SPAN class="code-keyword">protected</SPAN> void onChildStateChange(<SPAN class="code-object">int</SPAN> childCount, <SPAN class="code-object">int</SPAN> stoppedCount, <SPAN class="code-object">int</SPAN> failedCount) {
+
+ <SPAN class="code-keyword">if</SPAN> (a.isStopped() && (b.isStopped() || c.isStopped())) {
+ <SPAN class="code-comment">// lets stop the activity we're done
+</SPAN> stop();
+ }
+ }
+};
+
+<SPAN class="code-comment">// lets start the activities
+</SPAN>activity.startWithTimeout(timer, timeout);
+
+<SPAN class="code-comment">// now lets test things behave properly
+</SPAN>assertStarted(activity);
+
+a.stop();
+assertStarted(activity);
+b.stop();
+assertStopped(activity);</PRE>
+</DIV></DIV>
<H2><A name="BeanFlow-Buildingworkflows"></A>Building workflows</H2>
@@ -305,7 +348,32 @@
<P>There now follows a simple workflow example...</P>
+<DIV class="code"><DIV class="codeContent">
+<PRE class="code-java"><SPAN class="code-keyword">public</SPAN> class SimpleWorkflow <SPAN class="code-keyword">extends</SPAN> Workflow<SimpleWorkflow.Step> {
+ <SPAN class="code-keyword">public</SPAN> <SPAN class="code-keyword">static</SPAN> <SPAN class="code-keyword">enum</SPAN> Step {
+ stepA, stepB, stepC, stop
+ };
+
+ <SPAN class="code-keyword">public</SPAN> SimpleWorkflow() {
+ <SPAN class="code-keyword">super</SPAN>(Step.stepA);
+ }
+
+ <SPAN class="code-comment">// Workflow steps
+</SPAN> <SPAN class="code-comment">// -------------------------------------------------------------------------
+</SPAN> <SPAN class="code-keyword">public</SPAN> Step stepA() {
+ <SPAN class="code-keyword">return</SPAN> Step.stepB;
+ }
+
+ <SPAN class="code-keyword">public</SPAN> Step stepB() {
+ <SPAN class="code-keyword">return</SPAN> Step.stepC;
+ }
+
+ <SPAN class="code-keyword">public</SPAN> Step stepC() {
+ <SPAN class="code-keyword">return</SPAN> Step.stop;
+ }
+}</PRE>
+</DIV></DIV>
<P>As you can see the step is defined by an enumeration <B>Step</B> and we have a regular Java method to implement each step. The <EM>step method</EM> can then return the step to go to next after the current method terminates. If you return null or use a void method then the workflow suspends. </P>
@@ -321,7 +389,91 @@
</UL>
+<DIV class="code"><DIV class="codeContent">
+<PRE class="code-java"><SPAN class="code-keyword">public</SPAN> class ExampleWorkflow <SPAN class="code-keyword">extends</SPAN> Workflow<ExampleWorkflow.Step> {
+ <SPAN class="code-keyword">private</SPAN> <SPAN class="code-keyword">static</SPAN> <SPAN class="code-keyword">final</SPAN> Log log = LogFactory.getLog(ExampleWorkflow.class);
+ <SPAN class="code-keyword">private</SPAN> <SPAN class="code-object">int</SPAN> loopCount;
+ <SPAN class="code-keyword">private</SPAN> <SPAN class="code-object">long</SPAN> timeout = 500;
+ <SPAN class="code-keyword">private</SPAN> <SPAN class="code-object">String</SPAN> userEmailAddress;
+
+ <SPAN class="code-keyword">public</SPAN> <SPAN class="code-keyword">static</SPAN> <SPAN class="code-keyword">enum</SPAN> Step {
+ startStep, afterEnteredEmailStep, loopStep, waitForUserInputStep, forkStep,
+ aCompletedStep, abcCompletedStep, stop
+ };
+
+ <SPAN class="code-keyword">public</SPAN> ExampleWorkflow() {
+ <SPAN class="code-keyword">super</SPAN>(Step.startStep);
+ }
+
+ <SPAN class="code-comment">// Workflow steps
+</SPAN> <SPAN class="code-comment">// -------------------------------------------------------------------------
+</SPAN>
+ <SPAN class="code-keyword">public</SPAN> void startStep() {
+ <SPAN class="code-comment">// lets use an explicit goTo() to tell the workflow
+</SPAN> <SPAN class="code-comment">// which step to go to next; though we can just <SPAN class="code-keyword">return</SPAN> Strings
+</SPAN> addStep(Step.loopStep);
+ }
+
+ <SPAN class="code-comment">// lets use the <SPAN class="code-keyword">return</SPAN> value to specify the next step
+</SPAN> <SPAN class="code-keyword">public</SPAN> Step loopStep() {
+ <SPAN class="code-keyword">if</SPAN> (++loopCount > 3) {
+ <SPAN class="code-keyword">return</SPAN> Step.waitForUserInputStep;
+ }
+ <SPAN class="code-comment">// lets keep looping
+</SPAN> <SPAN class="code-keyword">return</SPAN> Step.loopStep;
+ }
+
+ <SPAN class="code-keyword">public</SPAN> void waitForUserInputStep() {
+ <SPAN class="code-comment">// we are going to park here until a user
+</SPAN> <SPAN class="code-comment">// enters a valid email address
+</SPAN> <SPAN class="code-comment">// so lets park the workflow engine
+</SPAN> }
+
+ <SPAN class="code-keyword">public</SPAN> Step afterEnteredEmailStep() {
+ <SPAN class="code-comment">// we are going to park here until a user
+</SPAN> <SPAN class="code-comment">// enters a valid email address
+</SPAN> log.info(<SPAN class="code-quote">"User entered email address: "</SPAN> + userEmailAddress);
+ <SPAN class="code-keyword">return</SPAN> Step.forkStep;
+ }
+
+ <SPAN class="code-keyword">public</SPAN> void forkStep() {
+ <SPAN class="code-comment">// lets fork some child flows
+</SPAN> TimeoutActivity a = <SPAN class="code-keyword">new</SPAN> TimeoutActivity();
+ TimeoutActivity b = <SPAN class="code-keyword">new</SPAN> TimeoutActivity();
+ TimeoutActivity c = <SPAN class="code-keyword">new</SPAN> TimeoutActivity();
+
+ log.info(<SPAN class="code-quote">"Forking off processes a, b, c"</SPAN>);
+ fork(a, b, c);
+
+ <SPAN class="code-comment">// now lets add some joins
+</SPAN> joinAll(Step.aCompletedStep, timeout, a);
+ joinAll(Step.abcCompletedStep, timeout, a, b, c);
+ }
+
+ <SPAN class="code-keyword">public</SPAN> void aCompletedStep() {
+ log.info(<SPAN class="code-quote">"child flow A completed!"</SPAN>);
+ }
+
+ <SPAN class="code-keyword">public</SPAN> Step abcCompletedStep() {
+ log.info(<SPAN class="code-quote">"child flows A, B and C completed!"</SPAN>);
+
+ <SPAN class="code-comment">// we are completely done now
+</SPAN> <SPAN class="code-keyword">return</SPAN> Step.stop;
+ }
+
+ <SPAN class="code-comment">// External events
+</SPAN> <SPAN class="code-comment">// -------------------------------------------------------------------------
+</SPAN> <SPAN class="code-keyword">public</SPAN> void userEntered(<SPAN class="code-object">String</SPAN> emailAddress) {
+ <SPAN class="code-keyword">if</SPAN> (emailAddress != <SPAN class="code-keyword">null</SPAN> && emailAddress.indexOf(<SPAN class="code-quote">"@"</SPAN>) > 0) {
+ <SPAN class="code-keyword">this</SPAN>.userEmailAddress = emailAddress;
+
+ log.info(<SPAN class="code-quote">"Lets re-start the suspended workflow"</SPAN>);
+ addStep(Step.afterEnteredEmailStep);
+ }
+ }
+}</PRE>
+</DIV></DIV>
<P>In the above example, each workflow step is implemented as a method. If the method returns a String it is interpreted as the next step which will be executed. Returning null (or using a void return type) will suspend the workflow.</P>
@@ -333,7 +485,28 @@
<P>To avoid typos between the workflow step enum and the methods in the workflow class, on startup we check that there are suitable methods available for the enum. Many thanks to <SPAN class="nobr"><A href="http://www.javarants.com/" title="Visit page outside Confluence" rel="nofollow">Sam<SUP><IMG class="rendericon" src="http://goopen.org/confluence/images/icons/linkext7.gif" height="0" width="0" align="absmiddle" alt="" border="0"></SUP></A></SPAN> for this idea! <IMG class="emoticon" src="http://goopen.org/confluence/images/icons/emoticons/smile.gif" height="20" width="20" align="absmiddle" alt="" border="0"> e.g. the following bad workflow is automatically caught and a useful error is generated.</P>
-</DIV>
+<DIV class="code"><DIV class="codeContent">
+<PRE class="code-java"><SPAN class="code-keyword">public</SPAN> class BadWorkflow <SPAN class="code-keyword">extends</SPAN> Workflow<BadWorkflow.Step> {
+
+ <SPAN class="code-keyword">public</SPAN> <SPAN class="code-keyword">static</SPAN> <SPAN class="code-keyword">enum</SPAN> Step {
+ startStep, fooStep, doesNotExistStep
+ };
+
+ <SPAN class="code-keyword">public</SPAN> BadWorkflow() {
+ <SPAN class="code-keyword">super</SPAN>(Step.startStep);
+ }
+
+ <SPAN class="code-comment">// Workflow steps
+</SPAN> <SPAN class="code-comment">// -------------------------------------------------------------------------
+</SPAN> <SPAN class="code-keyword">public</SPAN> Step startStep() {
+ <SPAN class="code-keyword">return</SPAN> Step.fooStep;
+ }
+
+ <SPAN class="code-keyword">public</SPAN> Step fooStep() {
+ <SPAN class="code-keyword">return</SPAN> Step.doesNotExistStep;
+ }
+}</PRE>
+</DIV></DIV></DIV>
<!--
<div class="tabletitle">
@@ -357,8 +530,8 @@
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Added by <A href="http://goopen.org/confluence/users/viewuserprofile.action?username=jstrachan">James Strachan</A>,
- last edited by <A href="http://goopen.org/confluence/users/viewuserprofile.action?username=jstrachan">James Strachan</A> on May 30, 2006
- (<A href="http://goopen.org/confluence/pages/diffpages.action?pageId=5092&originalId=8483">view change</A>)
+ last edited by <A href="http://goopen.org/confluence/users/viewuserprofile.action?username=gnodet">Guillaume Nodet</A> on Jan 07, 2007
+ (<A href="http://goopen.org/confluence/pages/diffpages.action?pageId=5092&originalId=15253">view change</A>)
(<A href="http://goopen.org/confluence/pages/editpage.action?pageId=5092">edit page</A>)
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