perf4j

http://perf4j.codehaus.org/

Presentation here.

Using LoggingStopWatch (start and stop) is a cleaner way of logging performance records.

Later you can process the perf log fils with LogParser to display statistics. You can even generate graphics.

AsyncCoalescingStatisticsAppender allows buffering of log events.


JmxAttributeStatisticsAppender allows you to monitor performance through JConsole

You can use @Profiled annotation to monitor a method
Also, you can weave perf4j monitoring with Spring or AspectJ.