[JMX-7] Extend Destract protocol on nil to handle Null references gracefully

Tue, 18 Sep 2012 23:20:50 -0500

JMX Attributes can have null references. Currently a Exception is thrown because the "null-type" is not handled via objects->data:

user> (jmx/mbean "java.lang:type=GarbageCollector,name=PS MarkSweep")
{:LastGcInfo #<IllegalArgumentException java.lang.IllegalArgumentException: No implementation of method: :objects->data of protocol: #'clojure.java.jmx/Destract found for class: nil>, :CollectionCount 0, :CollectionTime 0, :MemoryPoolNames #<String[] [Ljava.lang.String;@57b8fe29>, :Name "PS MarkSweep", :Valid true, :ObjectName #<ObjectName java.lang:type=GarbageCollector,name=PS MarkSweep>}

After applying this patch:

user> (jmx/mbean "java.lang:type=GarbageCollector,name=PS MarkSweep")
{:LastGcInfo nil, :CollectionCount 0, :CollectionTime 0, :MemoryPoolNames #<String[] [Ljava.lang.String;@2225be1e>, :Name "PS MarkSweep", :Valid true, :ObjectName #<ObjectName java.lang:type=GarbageCollector,name=PS MarkSweep>}

Clojure JIRA

[JMX-7] Extend Destract protocol on nil to handle Null references gracefully