Crash in my mod's fluid setup class. What am I doing wrong here? [solved]

[NetherNoah777]

As mentioned in a previous post, I'm working on porting my mod from MC 1.16.5 to MC 1.18.2 and now my fluid setup class is causing Minecraft to crash. What am I doing wrong with my fluid setup?

Fluid setup class

Crash report and log of last launch attempt

Edited May 4, 2023 by NetherNoah777

[warjort]

It is not the purpose of this forum to teach basic java.

But try this stripped down emulation of your code:

public class Test {

    public static record Fluid(Map<String, String> properties) {}

    public static Supplier<Fluid> FLUID = getFluid(Test.FLUID_PROPERTIES); // FLUID_PROPERTIES = null at this point
    public static Map<String, String> FLUID_PROPERTIES = Map.of("test", "Hello");

    public static Supplier<Fluid> getFluid(Map<String, String> properties) {
        return () -> new Fluid(properties);
    }

    public static void main(String[] args) {
        System.out.println(FLUID.get().properties()); // prints null
    }
}

Now try this:

public class Test {

    public static record Fluid(Map<String, String> properties) {}

    public static Supplier<Fluid> FLUID = getFluid(() -> Test.FLUID_PROPERTIES); // So pass a supplier instead to defer access
    public static Map<String, String> FLUID_PROPERTIES = Map.of("test", "Hello");

    public static Supplier<Fluid> getFluid(Supplier<Map<String, String>> properties) {
        return () -> new Fluid(properties.get());
    }

    public static void main(String[] args) {
        System.out.println(FLUID.get().properties()); // prints {test=Hello}
    }
}

 

If you don't understand how static initialisation and suppliers work, you have little chance at writing a mod correctly.

Both Forge and Vanilla use this technique ubiquitously.

[NetherNoah777]

I think you solved my problem. Thank you so much! I changed the parameter in get fluid() from ForgeFlowingFluid.Properties to Supplier<ForgeFlowingFluid.Properties> and Minecraft finally launched!

Edited May 4, 2023 by NetherNoah777