Finding More Null Pointer Bugs, But Not Too Many

In the summer of 2006, the FindBugs project was challenged to improve the null pointer analysis in FindBugs so that the authors could find more null pointer bugs. In particular, they were challenged to try to do as well as a publicly available analysis by Reasoning, Inc on version 4.1.24 of Apache Tomcat. Reasoning's report is a result of running their own static analysis tool and using manual auditing to remove false positives. Reasoning reported a total of 9 null pointer warnings in Tomcat 4.1.24, of which only 2 were reported by FindBugs 1.0. While they wanted to improve the analysis in FindBugs, they wanted to retain their current low level of false positives.