CODEWITHSUNDEEP
javajsongson
Taylan Selvi
Taylan Selvi

Reputation: 39

Loading Hashmap Through JSON

Hashmap:

public HashMap<Perk, Boolean> perks;
public HashMap<Perk, Boolean> getPerks() {
    return perks;
}

How I save (works fine, I'm using GSON by Google):

object.add("perks", builder.toJsonTree(player.perks));

Preview of save:

"perks": {
    "DAMAGE_AMPLIFIER": true
  }

How I am attempting to load but isn't working, error is below.

if (reader.has("perks")) {
    jsonToMap(reader.get("perks").toString(), player);
}

jsonToMap method:

    public static void jsonToMap(String t, Player player) throws JSONException {

    JSONObject jObject = new JSONObject(t);
    Iterator<?> keys = jObject.keys();

    while(keys.hasNext()) {
        String key = keys.next().toString();
        boolean value = jObject.getBoolean(key); 
        player.perks.put(Perk.valueOf(key), value);
    }
}

Error:

java.lang.NullPointerException
at com.callisto.world.entity.impl.player.PlayerLoading.jsonToMap(PlayerLoading.java:730)
at com.callisto.world.entity.impl.player.PlayerLoading.getResult(PlayerLoading.java:684)

Upvotes: 1

Views: 119

Answers (1)

Veselin Davidov
Veselin Davidov

Reputation: 7071

If I have to guess perks is null and that's why when you do put you get a null pointer. Change it to:

public HashMap<Perk, Boolean> perks=new HashMap<>(); //We init the hashmap here so we can putt stuff after that
public HashMap<Perk, Boolean> getPerks() {
    return perks;
}

Also you might even change it to : Map<Perk, Boolean> perks=new HashMap<>(); and use the interface and not the implementation in your methods

Upvotes: 1

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