Abstract
JESP is a tool for statically examining the usage of user thrown exceptions in Java source code. Reported here are the first findings over a dataset of 31 publicly available Java codes, including the JavaSpecs. Of greatest interest to compiler writers are the findings that most Java exceptions are thrown across method boundaries, trys and catches occur in equal numbers, finallys are rare, and programs fall into one of two categories, those dominated by throw statements and those dominated by catch statements.