This extremely simple HTTP service demonstrates the use of several libraries:
- jersey-metrics-filter, automatic metrics for all Jersey resource methods
- jersey-new-relic, Jersey integration into New Relic monitoring
- jetty-http-server-wrapper, a simple wrapper around the Jetty http server
- jersey-cors-filter to apply CORS headers to Jersey HTTP responses
- url-builder to safely build URLs
To use it, all you need to do is copy newrelic/newrelic.yml.template to newrelic/newrelic.yml and edit the license_key field to have your New Relic license key. If you do not have a New Relic account, you can run it without doing this step and though you'll have a stack trace show up in the logs, everything except actually reporting data to New Relic's systems will still work fine.
Once that is done, run the service with gradle run. It will make some HTTP requests to itself once a second so that some data will get sent to New Relic. Once the service has been running for a few minutes, check your New Relic dashboard. (It takes a few minutes for New Relic's webapp to update.) It intentionally has a few responses with an error status code (409) occasionally.
You can also open up jconsole or jvisualvm or the standalone VisualVM app or any other JMX browser to look at what metrics are being reported (look in the metrics namespace).