trial and stderr

Am I out of my mind for thinking that some linter or other should be able to recognize the following code as buggy?

package com.company;

public class Main {

    public String greeting = "hey";

    private Main anotherMain;

    public Main getAnotherMain() {
        return anotherMain;
    }

    public void setAnotherMain(Main main) {
        this.anotherMain = main;
    }

    public static void main(String[] args) {
        Main main = new Main();
        System.out.println(main.getAnotherMain().greeting);
    }
}

I expect a linter to tell me that the unchecked dereference main.getAnotherMain().greeting could produce an NPE because anotherMain defaults to null.

I tried SpotBugs, NullAway, and the IntelliJ static checker, and none of them can catch this. Bug filed against SpotBugs. We'll see how it goes.

Type safety without null safety is like a biohazard suit with an open face.

This is very typical Java code. It exhibits obnoxiously verbose typing, and yet can crash your application with NullPointerExceptions at runtime.

SuperDatabaseConnector superDatabaseConnector = SuperDatabaseConnector.getInstance();

getResultsFrom(superDatabaseConnector);

public static SomethingElseButMaybeNull getResultsFrom(SuperDatabaseConnector superDatabaseConnector) {
  return superDatabaseConnector.getResults();
}

Java is a bad language and you shouldn't use it.