A prototype for an Nbt serialization lib.

BannerData.java

public interface BannerData extends NbtStored {

    // If no argument is given, the attribute is saved with the name of the method
    @Nbt String id();

    // The attributes of this compound tag are collapsed into this NBT data
    @Nbt.Collapse Vec3i position();

    // Could be replaced with a TextColor, I'm not sure
    // 'Base' is set as the name
    @Nbt(name = "base") String color();

    // Typical nested data
    @Nbt List<BannerPattern> patterns();

    interface BannerPattern extends NbtStored {

        // Could be replaced with a TextColor, I'm not sure
        @Nbt String color();

        // Almost certain this is a string internally
        @Nbt String pattern();

    }

}

Nbt.java

public @interface Nbt {

    String name() default "";
    String value() default "";

    public @interface Collapse {

    }

}

Vec3i.java

public interface Vec3i extends NbtStored {

    @Nbt int x();
    @Nbt int y();
    @Nbt int z();

}