This example demonstrates the following aspects of the JMX support available with Spring Integration:
- JMX Attribute Polling Channel
- JMX Operation Invoking Channel Adapter
StopWatch is a Managed Bean. It is bootstraped and deployed using annotation support (@Component, @ManagedResource) and component scanning functionality provided by Spring JMX. Internally StopWatch simply runs a task that increments the value of its seconds attribute by 1 every second.
The JMX Attribute Polling Channel Adapter simply polls a managed attribute seconds of the StopWatch MBean identified by the name:
It sends its value to a seconds channel. The interesting part is that the seconds channel is a publish-subscribe-channel and has two subscribers:
- Stdout Channel Adapter which prints the value of the polled attribute to the console
- Filter which essentially waits till the payload value is 10
Once the payload value is 10, the filter sends the Message to a reset channel, which is represented as JMX Operation Invoking Channel Adapter. That adapter simply invokes the reset operation on the same StopWatch MBean resetting the seconds attribute value back to 1 and the process repeats.
To run the JMX Adapter sample simply execute JmxAdapterDemoTest. You will see output similar to this, which will loop for ~20 seconds:
1 2 3 4 5 6 7 8 9 10 1 2 3 . . .