jMonitor: Java Runtime Event Specification and Monitoring Library

jMonitor is a pure Java library and runtime utility for specifying event patterns and associating them with user provided event monitors that get called when the specified Java runtime events occur during the execution of legacy Java applications. jMonitor APIs define an event specification abstraction layer allowing programmers to design event patterns they would like to monitor during the runtime execution of legacy Java applications. jMonitor instrumentation works at the Java bytecode level and does not require the presence of source code for the Java application that is being monitored. jMonitor overloads the dynamic class loader and takes the event specification and monitors (in the form of Java class files) as additional arguments when launching the target Java application. The class bytecodes of the monitored Java program are instrumented on the fly by the jMonitor class loader according to the needs of the externally specified jMonitor event patterns and event monitors.