import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.FileOutputStream;
import java.lang.String;
import java.util.LinkedHashMap;
import java.util.Map;

public class WordStatInput {
    public static void addWord(Map<String, Integer> words, String word) {
        if (word.length() > 0) {
            // :NOTE: extra action -- read documentation about Map and .putIfAbsent()
            words.putIfAbsent(word, words.getOrDefault(word, 0));
            words.replace(word, words.get(word), words.get(word) + 1);
        }
    }
    public static void main(String[] args){
        Map<String, Integer> words = new LinkedHashMap<>();
        try {
            Reader reader = new BufferedReader(new InputStreamReader(
                    new FileInputStream(args[0])
            ));
            try {
                char symbol;
                StringBuilder word = new StringBuilder();
                int read = reader.read();
                symbol = (char) read;
                while (read > -1) {
                    if (Character.isLetter(symbol) || symbol == '\'' || Character.DASH_PUNCTUATION == Character.getType(symbol)) {
                        word.append(symbol);
                    } else {
                        addWord(words, word.toString().toLowerCase());
                        word.delete(0, word.length());
                    }
                    read = reader.read();
                    symbol = (char) read;
                }
                addWord(words, word.toString().toLowerCase());
            } finally {
                reader.close();
            }
            // :NOTE: you already catch IOException, why do you add "try" here?
            try {
                BufferedWriter writer = new BufferedWriter(
                        new OutputStreamWriter(
                                new FileOutputStream(args[1])
                        )
                );
                try {
                    for (Map.Entry<String, Integer> output : words.entrySet()) {
                        writer.write(output.getKey() + " " + output.getValue() + System.lineSeparator());
                    }
                } finally {
                    writer.close();
                }
            } catch (IOException e) {
                System.out.println("I/O Exception: " + e.getMessage());
            }
        // :NOTE: it's better to clarify the exception with the file missing to the user, if it occurs
        } catch (IOException e) {
            System.out.println("I/O Exception: " + e.getMessage());
        }
    }
}