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Comment by corytheboyd | Hacker News Reader

> Without a more sophisticated type system that represented nullability, you can get NullPointerException anywhere.

I started working in Java a few months ago and holy shit does this stick out like a sore thumb. Null checks cascade down from gods domain all the way to hell. But oop we missed one here and caused an outage lol add one more! So much wasted human effort around NPE, and yet, we sit around in a weekly meeting getting yelled at about how stability needs to be taken more seriously. Hrm.

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C# half-fixes this with its nullable annotations. I say half-fixes, because the boundary between code that supports them and code that does not is leaky, so you can make a mistake that leaks a null into a non-nullable variable.

If you build an entire program with nullability checking on it's pretty great, though.

Java, or at least Lombok, seems to have a @NonNull annotation that does what I want— cause code not to build that fails the check, and forces propagation of the annotation.

Reality does indeed feel exactly like what you mentioned with C#, though. The annotation is going to be missing where it’s needed most unless something forces the whole project to use it.

check JSpecify (https://jspecify.dev) - it's the standardised null annotation package for Java. Intellij understands the annotations so you generally get decent null-checking across your codebase.

Even better, apply at the package level via `package-info.java` (unfortunately sub-packages need to be individually marked as well)

  @NullMarked
  package com.foo;

  import org.jspecify.annotations.NullMarked;

Kotlin fixes the null handling problem too, and with the added benefit of being able to gradually migrate Java code.

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