Example: CharacterFrequencyStreamGrouping in Java

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// CharacterFrequencyStreamGrouping
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        String text = "hello world";

        // Step 1: Convert the string to an IntStream of character codes
        Map<Character, Long> charFrequencies = text.chars()
            // Step 2: Map each int (character code) to a Character object
            .mapToObj(c -> (char) c)
            // Step 3: Collect into a Map, grouping by character and counting occurrences
            .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));

        // Step 4: Print the resulting map
        System.out.println("Stream (groupingBy, counting) frequencies: " + charFrequencies);
    }
}