EMMA Java code coverage tool

EMMA is an open-source toolkit for measuring and reporting Java code coverage. EMMA can instrument classes for coverage either offline (before they are loaded) or on the fly (using an instrumenting application classloader). The coverage stats are aggregated at method, class, package, and "all classes" levels. EMMA can instrument individial class files or entire jars.

It outputs the report in the form of plain text, HTML, XML.