We have Java Dataflow Analysis (DFA), which is able to derive facts about your program: possible exceptions, conditions that are always true/always false, and more. It performs an abstract interpretation of the source code, allowing it to gather information about the code execution before the code is executed. However, it knows almost nothing about the inputs to the code. Well technically, if the method parameter is annotated as @NotNull the analysis trusts this annotation and assumes that null cannot appear here, but this is only a tiny bit of information. On the other hand, we have the debu

IntelliJ IDEA ships with thousands of Java code inspections. Most of them work like very advanced regular expressions: they look for specific patterns in the code which look like typos, are not very performant, confusing, or overly verbose. However one of them is not of that kind. Its name is “Constant conditions & exceptions” which sounds somewhat confusing. In fact, it performs data flow analysis of Java methods using a technique called “symbolic execution” and reveals suspicious facts about the code. Here are some examples of the facts it can reveal: Dereference may cause a NullPoin