Loading a HashMap saved to file

Hey guys, I am having issues reading HashMaps that I save to file.

Here is an example:

I have a HashMap<Integer, String>, and this is how it writes to file:

Code:

messages:
  75: This is a test message.

It works fine on the writing end, but I am having issues retrieving the data. Here is what I thought would work:

Code:

        for(Map<?, ?> entry : this.config.getMapList("messages"))
        {
            for(Map.Entry<?, ?> map : entry.entrySet())
            {
               exampleHashMap.put((Integer) map.getKey(), (String) map.getValue());
            }
        }

I am getting an NPE with the first line. Any ideas/help?

 

this.config is null ?

Still, I'm unsure if getMapList() would return what you need... sounds more like you need getConfigurationSection() and getKeys()... I dunno :-?
Did you save it as a MapList or did you use config.set("messages.75", "This is a tset message.") (raw example) ?

 

Here is how I am saving the HashMap<Integer, String> object:

Code:

this.config.set("messages", exampleHashMap);

If I so config.getConfigurationSection("messages").getKeys(), would it return all of the objects under messages, such as "messages.75" and "messages.100"?

 

No, it will return all keys, "75", "100", etc, and you can use config.getString("messages." + key) to get the value.
But if the getMapList() works you should use that.

 

It isn't working for me, I get an NPE. So I guess I'll try the roundabout way.

 

I don't think you fully understand what a NPE is...
It's simple actually, all variables are pointers to objects, if that variable is not pointing to any object it's null... therefore you can't call any methods on nothing.

Example:

null pointer exception code example (open) null pointer exception code example (close)

Code:

List<String> test; // not asigned is the same as asigning it to null

list.add("whatever"); // NPE here

So, you either try and find that null pointer OR post the code (more code, where all variables are created and asigned) and I'll help

 

dark navi
Be sure to save your config file when you're done. If saving to a config doesn't work, try this: http://wiki.bukkit.org/Plugin_Tutorial#Saving.2FLoading_a_HashMap

 

You should be using getConfigurationSection("messages") then you can turn that into a hashmap or use it as is.