How to Calculate Word Frequencies in a List Using Java 8?

Word frequency counting in Java 8

How to count the frequency of a word in a list using Java 8?

<code class="java">List<String> wordsList = Lists.newArrayList("hello", "bye", "ciao", "bye", "ciao");</code>

The result should be:

<code class="java">{ciao=2, hello=1, bye=2}</code>

At first, I expected to use the map and reduce method, but the actual method is slightly different.

<code class="java">Map<String, Long> collect = wordsList.stream()
    .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));</code>

Or for integer values:

<code class="java">Map<String, Integer> collect = wordsList.stream()
     .collect(Collectors.groupingBy(Function.identity(), Collectors.summingInt(e -> 1)));</code>

EDIT

I also added how to sort the map by value:

<code class="java">LinkedHashMap<String, Long> countByWordSorted = collect.entrySet()
            .stream()
            .sorted(Map.Entry.comparingByValue(Comparator.reverseOrder()))
            .collect(Collectors.toMap(
                    Map.Entry::getKey,
                    Map.Entry::getValue,
                    (v1, v2) -> {
                        throw new IllegalStateException();
                    },
                    LinkedHashMap::new
            ));</code>

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