Random text generation example (The Practice of Programming)

Markov.java

import java.util.*;

public class Markov {

    final static int MAX = 100;

    public static void main(String[] args) {
        Map<List<String>,List<String>> map = new HashMap<>();

        List<String> prefix = Arrays.asList("", "");
        try (Scanner scanner = new Scanner(System.in)) {
            while (scanner.hasNext()) {
                String word = scanner.next();
                map.putIfAbsent(prefix, new ArrayList<>());
                map.get(prefix).add(word);
                prefix = Arrays.asList(prefix.get(1), word);
            }
            map.putIfAbsent(prefix, new ArrayList<>());
            map.get(prefix).add("");
        }

        Random rand = new Random();
        prefix = Arrays.asList("", "");
        for (int i=0; i<MAX; i++) {
            List<String> suffices = map.get(prefix);
            String word = suffices.get(rand.nextInt(suffices.size()));
            if (word.equals("")) break;
            System.out.println(word);
            prefix = Arrays.asList(prefix.get(1), word);
        }
    }
}