<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<body link="#355491" alink="#4262a1" vlink="#355491" style="background: #e2e2e2; margin: 0; padding: 20px;">
<div>
<table cellpadding="0" bgcolor="#FFFFFF" border="0" cellspacing="0" style="border: 1px solid #dadada; margin-bottom: 30px; width: 100%; -moz-border-radius: 6px; -webkit-border-radius: 6px;">
<tbody>
<tr>
<td>
<table border="0" cellpadding="0" cellspacing="0" bgcolor="#FFFFFF" style="border: solid 2px #ccc; background: #dadada; width: 100%; -moz-border-radius: 6px; -webkit-border-radius: 6px;">
<tbody>
<tr>
<td bgcolor="#000000" valign="middle" height="58px" style="border-bottom: 1px solid #ccc; padding: 20px; -moz-border-radius-topleft: 3px; -moz-border-radius-topright: 3px; -webkit-border-top-right-radius: 5px; -webkit-border-top-left-radius: 5px;">
<h1 style="color: #333333; font: bold 22px Arial, Helvetica, sans-serif; margin: 0; display: block !important;">
<!-- To have a header image/logo replace the name below with your img tag -->
<!-- Email clients will render the images when the message is read so any image -->
<!-- must be made available on a public server, so that all recipients can load the image. -->
<a href="https://community.jboss.org/index.jspa" style="text-decoration: none; color: #E1E1E1">JBoss Community</a></h1>
</td>
</tr>
<tr>
<td bgcolor="#FFFFFF" style="font: normal 12px Arial, Helvetica, sans-serif; color:#333333; padding: 20px; -moz-border-radius-bottomleft: 4px; -moz-border-radius-bottomright: 4px; -webkit-border-bottom-right-radius: 5px; -webkit-border-bottom-left-radius: 5px;"><h3 style="margin: 10px 0 5px; font-size: 17px; font-weight: normal;">
Workitem handler thread safety issues
</h3>
<span style="margin-bottom: 10px;">
created by <a href="https://community.jboss.org/people/ghuazh">hua zhong</a> in <i>jBPM</i> - <a href="https://community.jboss.org/message/740086#740086">View the full discussion</a>
</span>
<hr style="margin: 20px 0; border: none; background-color: #dadada; height: 1px;">
<div class="jive-rendered-content"><p>Hi, all.</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p>Human workitem handler need be resigted to ksession before human task process start.</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p>I need to pass some object into workitem handler, but it's not tread safety.</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p>code:</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><pre class="jive-pre"><code class="jive-code jive-java">CommonSingleObjectWorkHandler handler = <font color="navy"><b>new</b></font> SingleObjectWorkHandler(ksession);
handler.setSingleObject(so);
</code></pre><p>In handler:</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><pre class="jive-pre"><code class="jive-code jive-java">setSingleObject(ISingleObject so)<font color="navy">{</font>
this.so = so;
<font color="navy">}</font>
</code></pre><p>and in executeWorkItem method, we have code to use "so".</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><pre class="jive-pre"><code class="jive-code jive-java">@Override
    <font color="navy"><b>public</b></font> <font color="navy"><b>void</b></font> executeWorkItem(WorkItem workItem, WorkItemManager manager) <font color="navy">{</font>
        Task task = createTaskBasedOnWorkItemParams(workItem);
        ContentData content = createTaskContentBasedOnWorkItemParams(workItem);
        connect();
        <font color="navy"><b>try</b></font> <font color="navy">{</font>
            getClient().addTask(task, content);
            String userId = (String) workItem.getParameter(<font color="red">"ActorId"</font>);
            <font color="darkgreen">//...we use "so" here............................................</font>
        <font color="navy">}</font> <font color="navy"><b>catch</b></font> (Exception e) <font color="navy">{</font>
            <font color="navy"><b>if</b></font> (action.equals(OnErrorAction.ABORT)) <font color="navy">{</font>
                manager.abortWorkItem(workItem.getId());
            <font color="navy">}</font> <font color="navy"><b>else</b></font> <font color="navy"><b>if</b></font> (action.equals(OnErrorAction.RETHROW)) <font color="navy">{</font>
                <font color="navy"><b>if</b></font> (e <font color="navy"><b>instanceof</b></font> RuntimeException) <font color="navy">{</font>
                    <font color="navy"><b>throw</b></font> (RuntimeException) e;
                <font color="navy">}</font> <font color="navy"><b>else</b></font> <font color="navy">{</font>
                    <font color="navy"><b>throw</b></font> <font color="navy"><b>new</b></font> RuntimeException(e);
                <font color="navy">}</font>
            <font color="navy">}</font> <font color="navy"><b>else</b></font> <font color="navy"><b>if</b></font> (action.equals(OnErrorAction.LOG)) <font color="navy">{</font>
            <font color="navy">}</font>
            e.printStackTrace();
        <font color="navy">}</font>
</code></pre><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p>But the handler will be used by other session. and invoke the setSingleObject()  mothod to make data changed.</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p>We have only one method to start process, and every time it'll create a new ksession and handler.</p><p>I don't know the reason why the handler will shared in those sessions?</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p>To solve this problem, we need to pass "singleObject" to a process parameter, in executeWorkItem() method get the "singleObject" from workitem parameter.</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><h3 class="r"><a class="jive-link-external-small" href="http://www.zeropaid.com/bbs/threads/6765-i-hope-this-is-the-last-problem-i-ever-get-and-the-final-solution" target="_blank">http://www.zeropaid.com/bbs/threads/6765-i-hope-this-is-the-last-problem-i-ever-get-and-the-final-solution</a></h3></div>
<div style="background-color: #f4f4f4; padding: 10px; margin-top: 20px;">
<p style="margin: 0;">Reply to this message by <a href="https://community.jboss.org/message/740086#740086">going to Community</a></p>
<p style="margin: 0;">Start a new discussion in jBPM at <a href="https://community.jboss.org/choose-container!input.jspa?contentType=1&containerType=14&container=2034">Community</a></p>
</div></td>
</tr>
</tbody>
</table>
</td>
</tr>
</tbody>
</table>
</div>
</body>
</html>