Obtain Value from nested Hashtable Map

[cobalt cradle]

I am creating a program that initially uses nested Hashtables in the format:

public static Hashtable<Integer, Map<String, String>> commonOpposites = new Hashtable<>(){{...}};

Purpose
The functionality of the nested hashtable is to hold values of 'common opposites' (antonyms for clarity). I have already structured most of the code to put values within the hashtable but I am having a difficult time figuring out how to obtain only values within the key : {key = value} format of the nested hashtable. Here is how I placed values into the table (I put them in pairs of 2 for ease of readability):

public static Hashtable<Integer, Map<String, String>> commonOpposites = new Hashtable<>(){{
    put(1, Map.of("absent", "present")); put(2, Map.of("accurate", "inaccurate"));
    put(3, Map.of("against", "for")); put(4, Map.of("all", "none"));
    ...
}};

I am not even sure if this is the best way to write code like this, however, I have tried using for loops with Entry, tried using built in functions and looked at examples like:

Map map = new HashMap();
((Map)map.get( "keyname" )).get( "nestedkeyname" );

I am not sure how I would access them, if someone could explain to me the complexities of something like this, it would mean a lot!

[tidal phoenix]

Hey, @cobalt cradle!
Please remember to /close this post once your question has been answered!

[fallow gyro]

I'm afraid there is nothing complex. It's a Map of Maps of Strings. That works as usual.
String value = map.get("key").get("subkey");

It may be worth verifying, however, whether you truly want nested maps, rather than a composed key

Oh, right, the top-level key is of type Integer. So it would be rather:
String value = map.get(2).get("subkey");

[cobalt cradle]

Ic Ic it does seem very straightforward but I have had some difficulty using it within an if statement

basically ```java
if(dict.getCommonOpposites().entrySet().contains(Key)) {
TypeWriter("""
Correct ✔️
""", 20, Colors.GREEN_BOLD);
}else {
TypeWriter("""
Incorrect ❌
""", 20, Colors.RED_BOLD);
}

I tried to check whether a user inputs a value that is an antonym of the word I provide them such as ```java
What is the opposite of absent?
User In: present
Correct!

or
What is the opposite of absent?
User In: here
Incorrct, Try again!

[quiet dragon]

What is the use of the first map? Int index is not used as far as i see. Would it be an option to switch to a set of maps or even switch to pair from apache commons lang3? Set<Pair<String,String>>? Since you call entryset on a map anyway?

set.stream().map(pair -> pair.getLeft().equals(someInput)).map(Pair::getRight).findFirst().ifPresentOrElse(v -> logger.info("found " + v), () -> logger.info("not found"))

Or use Map<String,String>?

But then your key is unique

[fallow gyro]

Looks like nested maps aren't what's needed anyway.
More like two-ways Map, which isn't provided by Java, but you can always enter a word and its opposite with both sides

[cobalt cradle]

initially it was used in order to obtain the key:value pairs of the second map more efficiently and save me time on having to continuously write "some word" instead just call from its index key

But after looking at it I dont think its that useful I should instead use what you suggest Set<Pair<String, String>>

[quiet dragon]

You can still use Set of maps if you dont want an extra library

[cobalt cradle]

god if this was python it would be soo nice or any other language that can make this efficient

[cobalt cradle]

Im okay with using an extra library if it does prove to be more effective

I will look into your suggestion, I thank you for all the help!

[fallow gyro]

This isn't about efficiency, it's just impossible to come and imagine that nested maps are a useful tool for that

It would have been the same with Python

[cobalt cradle]

Ic well you are right its not really useful to use a nested map for something like what I am aiming for, but I was just testing some things out