COMPAS J2EE is a non-intrusive performance instrumentation and monitoring toolkit for J2EE.
It uses adaptive monitoring to automatically adjust the target coverage. COMPAS is completely portable across J2EE application servers and OSs.
JQuantify is a Java package providing lightweight statistics describing the frequency and
duration of application-specific events. Developers use a simple API to insert count-points or start/stop boundaries at appropriate places within their system.
http://jmsloadtester.marcel-sauer.de JMS Load Tester is a small command line based Java (>1.5) application to load test JMS brokers like SonicMQ, ActiveMQ, OpenJMS and others. It can be configured with a property file.