在Java中与另一个地图交叉地图

Question

I have a map:

 private Map<String, Map<String, ArrayList<String>>> map1; 

where map contains:

 ArrayList<String> is a list with values like : "A, B, C, .."
 Map<String, ArrayList<String>> -> Here the key is: LINEA, PARCIAL, TOTAL
 Map<String, Map<String, ArrayList<String>>> the key is: "B,D,F, ..." // similar 

values of the map1

 {
 "map1":
     {
        "A": {  //key
            "LINEA": //key internal map
                ["B", "C", "D", "E", "F", "G"] //List
        },
        "H": { //key
            "LINEA":  //key internal map
                ["H", "I", "B", "C", "J", "A"] //List
        },
        "I": {
            "LINEA": 
                ["I", "H", "B", "C", "J", "A"]
        },
        "D": {
            "LINEA": 
                ["D", "G", "E", "F", "J", "A", "K"]
        },
        "K": {
            "LINEA": 
                ["D", "E", "F", "G"]
        },
        "C": { //key
            "LINEA":  //key internal map
                ["J", "A"],
            "PARCIAL":  //List
                ["J", "A"], //Listmap
            "TOTAL":  //key internal map
                ["J", "A"] //List
        },
        "B": {
            "PARCIAL": 
                ["B", "H", "I", "C", "J", "A"]
        },
        "E": {
            "PARCIAL": 
                ["E", "G", "F", "J", "A", "K"],
            "TOTAL": 
                ["D", "G", "F", "J", "A", "K"]
        },
        "F": {
            "TOTAL": 
                ["F", "D"],
            "PARCIAL": 
                ["K"]
        }
    }
}

And I have another map:

 Map<String,List<String>> map2;

where map cointains:

List<String> is a list with values like: 1, 2, 3, 4
   Map<String,List<String>> key is : "A,C,D,H,..."  // similar values of map1 

list and key

{
    "map2": {
        "A": [1, 2, 3, 4],
        "F": [1, 2, 4],
        "D": [2,6]
        "K": [7,8,9]
    }
}

I need to cross the maps:

I need reeplace the "A, B, C,E,..." values in map1 with the values in map2.

the result like:

"map1":
     {
        "1": {  //reeplace by F
            "LINEA": //key internal map
                [1, 4, 2, 6], // REEMPLACE BY ["F", "D"] because is the partial list of F in map1,  F = [1, 2, 4] , D = [2,6]
        },
        "1": { //reeplace by F
            "PARCIAL":  //key internal map 
                [7,8,9] // REEMPLACE BY ["K"] 
        },

        .
        .
        .

I have a solution with 4 for. But I don't know whether to nest 4 times is a bad practice.

Who can help me with a good solution for this problem.

Answer 1

Four nested loops is a good signal for "refactoring is needed".
Ignoring the conversion of the map keys, which is not clear to me, and assuming map1 and map2 are give static fields, remapping of values into newMap can be achieved by :

Map<String, Map<String, ArrayList<String>>> newMap = new HashMap<>();
    for(String key : map1.keySet() ) {
        newMap.put(convertKey(key), convertEntry(key));
    }
}

Where convertKey and convertEntry are defined by

private static String convertKey(String key) {
    // TODO add key conversion logic 
    return key;
}

private static Map<String, ArrayList<String>> convertEntry(String key) {

    Map<String, ArrayList<String>> map = map1.get(key);
    Map<String, ArrayList<String>> returnedMap = new HashMap<>();

    for(String keyOfInnerMap : map.keySet()) {
        ArrayList<String> newValues = mapValues(map.get(keyOfInnerMap));
        returnedMap.put(keyOfInnerMap, newValues);
    }

    return returnedMap;
}

private static ArrayList<String> mapValues(ArrayList<String> values) {

    Set<String> newValues = new HashSet<>();
    for(String key : values) {

        List<String> v = map2.get(key);
        if(v != null) {
            newValues.addAll(v);
        }
    }

    return new ArrayList<>(newValues);
}