The UML provides means to specify both static and dynamic aspects of object-oriented software systems and can be used to assist in all phases of a software development process. With growing support by CASE tools, its applications become more and more widespread. In addition to the automatic generation of class code from diagrams, the recovery of static structure from source code has become common, too. In this paper however, we focus on the extraction of behavioural information from program code. We introduce a restricted meta model for Java code and present a new approach to extract the required data, which will then be rendered as UML collaboration diagrams.