http://dev.clojure.org/jira This file is an XML representation of an issue en-us 4.4 649 25-07-2011 http://dev.clojure.org/jira/browse/JMX-6 java.jmx <p>The documentation suggests that you create a JMX bean (clojure.java.jmx.Bean) by calling clojure.java.jmx/create-bean on a reference to a map whose values are the actual values you want as attributes: for instance, (create-bean (ref {:calls-so-far 0})). However, if you do this, when you get the attribute out using .getAttribute the result is the actual state value, and not the javax.management.Attribute in question as the interface specifies. This also causes a ClassCastException when you try to call .getAttributes or anything else that tries to add the attributes to an AttributeList.</p> <p>The attached patch fixes this problem by wrapping the state value in a call to Attribute. so that .getAttribute yields an Attribute, and modifies objects-&gt;data to descend into Attribute values accordingly. The tests work, and it works for my use case, but I do not know whether this is the right solution in general.</p> JMX-6

Result of clojure.java.jmx.Bean.getAttribute is not a javax.management.Attribute

Defect Minor Resolved Completed Chris Jeris Chris Jeris Thu, 26 Jul 2012 09:07:14 -0500 Fri, 28 Sep 2012 21:59:32 -0500 Fri, 28 Sep 2012 21:59:32 -0500 0 1 <p>Chris,</p> <p>Thanks for submitting a patch for this. I'll be able to review it sometime in the next few days hopefully.</p> <p>Chris,</p> <p>Sorry for the delay.</p> <p>Whats the reason for the addition to objects-&gt;data? By that point we've already read the attribute list for a bean and are processing the attribute values right?</p> <p>I don't see whats wrong in the implementation of the DynamicMbean interface:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre> ({:name getAttribute, :return-type java.lang.Object, :declaring-class javax.management.DynamicMBean, :parameter-types [java.lang.String], :exception-types [javax.management.AttributeNotFoundException javax.management.MBeanException javax.management.ReflectionException], :flags #{:public :abstract}}) </pre> </div></div> <p>the return type is <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre> java.lang.Object</pre> </div></div> , not <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre> javax.management.Attribute</pre> </div></div> </p> <p>The documentation there is somewhat vague. Perhaps that part of the api shouldn't be changed. It seems like at least the .getAttributes implementation at least is wrong though. The documentation for AttributeList is clear that only Attribute objects should be added to the AttributeList, but it looks like all current jvm implementations (or ones we test with) don't do a good job of actually enforcing that.</p> <p><a href="http://docs.oracle.com/javase/1.5.0/docs/api/javax/management/AttributeList.html">http://docs.oracle.com/javase/1.5.0/docs/api/javax/management/AttributeList.html</a></p> <p>Do we know if any built in dynamic mbeans return Attribute objects or the actual values of a specific attribute?</p> <p>Ok, found better documentation here.</p> <p><a href="http://docs.oracle.com/cd/E19698-01/816-7609/6mdjrf83d/index.html">http://docs.oracle.com/cd/E19698-01/816-7609/6mdjrf83d/index.html</a></p> <p>So getAttribute should be returning an attributes value rather than an actual attribute object. But as I mentioned before, getAttributes should be returning a list of Attribute objects.</p> <p>Going to go ahead and update the patch accordingly.</p> <p>Updated patch. Look good <span class="nobr"><a href="http://dev.clojure.org/jira/secure/ViewProfile.jspa?name=bccjeris" class="user-hover" rel="bccjeris">^{<img class="rendericon" src="http://dev.clojure.org/jira/images/icons/user_12.gif" height="12" width="12" align="absmiddle" alt="" border="0"/>}Chris Jeris</a></span>?</p> <p>Looks good and works for my use case. Sorry for the delay &#8211; I appear not to have email notifications from this JIRA configured correctly.</p> <p>Committed.</p> Approval Accepted Global Rank Patch Accepted