Need feedback on how I should implement my 'recipe'

[Tavi007 2]

Hey all,

A little bit of context first: I'm trying to implement the Materia system from Final Fantasy 7. Basically the player can equip and combine items, that can result in some effect. I already have the effects in place (Each effect is a class which implements certain interfaces, that I defined previously), but now I would like to have some sort of 'crafting' system for the effects. I need a mapping, that maps up to 4 items to an effect.
Short example to clear things up: I have the FireMateria and the AreaMateria. Equipping the FireMateria on a pick will result in an autosmelt, while the AreaMateria will increase the amount of mined blocks (like TC hammer). Combining these 2 materias will result in a hammer-like mining with autosmelt. For each of these effect I have seperate classes (FireEffect, AreaEffect, FireAreaEffect) These are necessary, because some effects will be more abstract then just an autosmelt

Should I write my own recipe type or can those only map items to a resulting item? If a recipe type is not the answer, what could I do instead? Some kind of HashMap<customKey, Effect>? I just need some general direction and maybe some example code (for a custom recipe type) that I could analyze

[Lily Faerose 0]

this is the best example code I've found for custom recipes.   and no. custom recipes are not locked to items.  it's not to hard to pull a string out of the json object.  those can easily be turned into a resource location or whatever else you need.