In my Maven build, I use exec-maven-plugin to run an external tool for Java code generation. In this case the flatbuffers compiler (flatc).

By default, flatc always runs, so you always get a new .java file. This will always trigger Java compiler to run, which will in turn always trigger jar packaging to run, etc. I would like flatc to only run if it’s source file is updated, so I can get a properly incremental build and avoid needlessly recompiling.

After listening to a presentation about Domain Driven Security, I got some additional insights about what a data structure (as opposed to OOP object) should be able to do. Data structures (I call them struct) should have a subset of OOP features which I think is useful and harmless.

A struct should allow constructors. Such constructors can have two purposes, to convert one type of data into another and to validate the input. Such constructors should take parameters and be able to throw an exception if the input is invalid, to make it impossible to create an invalid instance of a struct. Each constructor should be required to set every field of the struct, and if no constructors are defined, a default one should be generated which simply takes all fields as parameters.

Several popular statically typed programming languages, including C++, Java and C#, have a serious design flaw. They make no useful distinction between objects in the OOP sense and plain data structures.

A plain data structure should only be a dumb container for data. It should not have any behaviour, only simple accessors for data items in it. It should not be possible to override data accessors. It should be clear and transparent what it does.