CODEWITHSUNDEEP
javadata-structureshashmap
dedpo
dedpo

Reputation: 502

Access a Hashmap within a Hashmap, and print it out in a format

    static HashMap<String, HashMap<String, List<Integer>>> BIGMAP= new HashMap<String, HashMap<String, List<Integer>>>();

This is a Hashmap if i were to print it out this is what i get:

SortedSet<String> keys = new TreeSet<String>(BIGMAP.keySet());
     for (String key : keys) {
     HashMap<String, List<Integer>> value = kmap.get(key);
     System.out.println(key + " : " + value);

     }

a.txt : {a=[20], to=[10]}
b.txt : {a=[4, 20], by=[16], is=[2], to=[13, 22]}
c.txt : {a=[15], as=[16, 17], in=[34], do=[9], to=[14]}

So i am trying to iterate through this "BIGMAP" the above for each key a.txt(String) there is a Value which is another map the structure of HashMap<String, List<Integer>>

...

OUTPUT:

a [15],[20],[4, 20],
as [16, 17],, ,, ,
by , ,, ,[16],
...so on...
...so on...
...so on...

EXPECTED/WANTED OUTPUT

a  20, 4:20 ,15
as   ,  , 16:17
by   , 16 ,

the printing format should be like above but obviously it should print in order from each textfile(string) which is a key in the outer hashmap

for example a 20, 4:20 ,15 "a" is word FOR That word , 20 is from the value where key isa.txt and 4:20 is from b.txt and 15 is from c.txt

As you can see i have something up there but its not doing exactly what i need. The colons are necessary to where there multiple numbers. it can ever sometimes be 4:20:50:92

Upvotes: 0

Views: 354

Answers (1)

shmosel
shmosel

Reputation: 50716

This will do the job in Java 8. Not my best work, but tested successfully with your sample values.

BIGMAP.values()
        .stream()
        .flatMap(m -> m.keySet().stream())
        .distinct()
        .sorted()
        .map(k -> k
                + " "
                + BIGMAP.entrySet()
                        .stream()
                        .sorted(comparing(Entry::getKey))
                        .map(e -> e.getValue()
                                   .getOrDefault(k, Collections.emptyList())
                                   .stream()
                                   .map(String::valueOf)
                                   .collect(joining(":")))
                        .collect(joining(", ")))
        .forEachOrdered(System.out::println);

Produces the following output:

a 20, 4:20, 15
as , , 16:17
by , 16, 
do , , 9
in , , 34
is , 2, 
to 10, 13:22, 14

Upvotes: 1

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