使用嵌套的 Map 打印 Map

Question

I have a Map of the following kind: HashMap<String, Map<String, Integer>> resultMap = new HashMap<>();

Where String(Key) = Website address;

Map<String,Integer> = String(key) -search word, Integer(value) - counter for found words.

How to print the Map correctly so that it looks like this:

1. webSite1 - randomWord = 30, randomWord2 = 15, randomWord3 = 0
2. webSite2 - randomWord = 9, randomWord2 = 8, randomWord3 = 1

Thanks in advance for any ideas!

Answer 1

Map has simple iterator forEach((key, value) -> your_consumer) , and the entries in the nested map may be converted into strings joined using Collectors.joining , so printing may be done as follows:

resultMap.forEach((k, v) ->
    System.out.println(k + " - " + 
        v.entrySet().stream()
         .map(e -> e.getKey() + "=" + e.getValue())
         .collect(Collectors.joining(", "))
);

Answer 2

If I've correctly understood you: In the outer loop, you should iterate the nested maps (as values), and in the internal loop(s) you can finally iterate keys and values of the nested map.

HashMap<String, Map<String, Integer>> map = new HashMap<>();
        for (Map<String, Integer> nestedMap : map.values()) 
        {
            for (String key : nestedMap.keySet()) {
                // some actions here
            }
            
            for (Integer value : nestedMap.values()) {
                // some actions here
            }
        }