Write a program that counts the occurrences of words in a text and displays the words and their occurrences in alphabetical order of words. The program uses a TreeMap to store an entry consisting a wo

rd and its count. Here's an example program in Java:

import java.util.Scanner;
import java.util.TreeMap;

public class WordCounter {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        TreeMap<String, Integer> wordCountMap = new TreeMap<>();
        System.out.println("Enter text (press Ctrl+D to end):");
        while (scanner.hasNext()) {
            String word = scanner.next().toLowerCase().replaceAll("[^a-z]+", "");
            if (!word.isEmpty()) {
                int count = wordCountMap.getOrDefault(word, 0);
                wordCountMap.put(word, count + 1);
            }
        }
        System.out.println("Word count:");
        for (String word : wordCountMap.keySet()) {
            System.out.println(word + " " + wordCountMap.get(word));
        }
    }
}

The program reads text from standard input using a `Scanner` and stores the word counts in a `TreeMap<String, Integer>`. Each word is converted to lowercase and stripped of non-alphabetic characters using a regular expression. The `getOrDefault` method is used to retrieve the current count for a word, and `put` is used to update the count. Finally, the program outputs the word counts in alphabetical order of words using a `for` loop over the key set of the `TreeMap`.