Possible Metallurgy Thing

package TFC.API.Crafting;

import java.util.HashMap;
import java.util.List;

import TFC.API.Metal;

public class AlloyComponentMetal {
    public AlloyComponentMetal(Metal metaltype, float units){
        this.metaltype=metaltype;
        this.units=units;
        this.subcomponents=null;
    }
    public AlloyComponentMetal(Metal metaltype, float units,HashMap<Metal,AlloyComponentMetal> subcomponents){
        this.metaltype=metaltype;
        this.units=units;
        this.subcomponents=subcomponents;
    }
    Metal metaltype;
    float units;
    HashMap<Metal,AlloyComponentMetal> subcomponents;
    public boolean hasSubcomponent(Metal metaltype){
        if (this.subcomponents == null){return false;}
        return this.subcomponents.containsKey(metaltype);
    }
    public boolean canCombine(AlloyComponentMetal other){
        if(this.metaltype != other.metaltype){return false;}
        if(this.subcomponents != null && other.subcomponents != null){
            java.util.Iterator<Metal> sub=this.subcomponents.keySet().iterator();
            while(sub.hasNext()){
                Metal type=sub.next();
                if(!(other.subcomponents.containsKey(type))){
                    //same alloy, different subcomponents, cannot combine
                    return false;
                }
                AlloyComponentMetal subA,subB;
                subA=this.subcomponents.get(type);
                subB=other.subcomponents.get(type);
                if(!subA.canCombine(subB)){
                    return false;
                }
            }
        }
        return true;
    }
    public AlloyComponentMetal combine(AlloyComponentMetal other){
        if(this.canCombine(other)){
            AlloyComponentMetal combined=new AlloyComponentMetal(this.metaltype,this.units+other.units);
            if(this.subcomponents != null && other.subcomponents != null){
                java.util.Iterator<Metal> sub=this.subcomponents.keySet().iterator();
                while(sub.hasNext()){
                    Metal type=sub.next();
                    if(!(other.subcomponents.containsKey(type))){
                        //same alloy, different subcomponents, cannot combine
                        return null;
                    }
                    AlloyComponentMetal subA,subB;
                    subA=this.subcomponents.get(type);
                    subB=other.subcomponents.get(type);
                    this.subcomponents.put(type, subA.combine(subB));
                }
            } else if(!(this.subcomponents == null && other.subcomponents == null )){
                //mismatched subcomponents
                return null;
            }
            return combined;
        } else {
            return null;
        }
    }
}