Помогите разобраться.
package com.javarush.task.task18.task1821;
/*
Встречаемость символов
*/
import java.io.*;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;
public class Solution {
public static void main(String[] args) throws IOException {
Map<Character, Integer> myMap = new TreeMap<>();
BufferedReader reader = new BufferedReader(new FileReader(args[0]));
String str = reader.readLine();
//str = str.toLowerCase();
char[] arr = str.toCharArray();
for (char c : arr) {
Integer count = myMap.get(c);
if(count == null){
myMap.put(c,1);
}else{
myMap.put(c, count + 1);
}
}
reader.close();
printMyMap(myMap);
}
private static void printMyMap(Map<Character, Integer> myMap) {
for (Map.Entry<Character, Integer> characterIntegerEntry : myMap.entrySet()) {
System.out.println(characterIntegerEntry.getKey() + " " + characterIntegerEntry.getValue());
}
}
}