1.14.4 How can I load a saved hashmap with a class inside it from a config?

What is your question? (Please explain more than in the title)

 

Loop through the keys in the config, insert the key (as the key) to the hashmap and the value in the config (as the value) to the hashmap

 

Code (Text):

for (String key : config.getConfigurationSection("clans").getKeys(false))
 

 

You're using .getStringList() wrong. You don't put the file name in the arguments, you put the name of the list.

Code (Java):

config.getStringList("Example Path");

Code (Text):

Example Path:
      -  Value 1
      - Value 2
      - Value 3

 

Code (Java):

// your map
Map<UUID, GamePlayer> dataMap = new HashMap<>();

// a GSON instance
final Gson gson = new Gson();

// save
getConfig().set("my.map", gson.toJson(dataMap));

// load
Map<UUID, GamePlayer> loadedData = gson.fromJson(getConfig().getString("my.map"), HashMap.class);
 

Not getting simpler than this.

Explanation: uses GSON (included JSON library from google in Spigot) to serialize the map and it content's and then read and map them back.

 

https://www.codejava.net/coding/java-getter-and-setter-tutorial-from-basics-to-best-practices

 

Sounds like poor project setup or code style

 

Please provide some actual useful information, like, what you tried and what isn't working.
If you want us to look with you, for you, please at least give us the chance.