How to sort a table created with Formatter?

I made an application that reads text from a file, counts each word, and puts everything into a table created with Formatter. Now I would like to sort the table by the number Occurrences per word. Here is my code so far:

java

package com.example.antonpaarapplication;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.*;
public class Application {
//Function for Initializing the Application.
public void run() {
System.out.println("Would you like to process the entire file(1) or just specific lines(2)?");
choice();
}
//Function for choosing whether to process the entire file at once or only select specific files to be processed.
public void choice() {
Scanner scanner = new Scanner(System.in);
int number = scanner.nextInt();
switch (number) {
case 1:
System.out.println("\nNumber 1 has been entered, processing whole file.\n");
processWholeFile();
break;
case 2:
System.out.println("\nNumber 2 has been entered, please specify lines to be processed. \n");
processSpecificLines();
break;
default:
System.out.println("Invalid, please try again.");
choice();
}
}
//Function for processing the entire File.
public void processWholeFile() {
Map<String, Integer> stringMap = new HashMap<String, Integer>();
Formatter formatter = new Formatter();
List<String> lines = readFile();
String string = String.join(" ", lines);
String[] arr = string.split(" ");
for (String s : arr) {
if (stringMap.containsKey(s)) {
stringMap.put(s, stringMap.get(s) + 1);
} else {
stringMap.put(s, 1);
}
}
formatter.format("%20s %20s\n\n", "Word", "Occurence");
for (Map.Entry<String, Integer> mapEntry : stringMap.entrySet()) {
if (mapEntry.getKey().substring(0, 1).equals("1")) {
formatter.format("%20s %20s\n", mapEntry.getKey(), mapEntry.getValue());
} else {
formatter.format("%20s %15s\n", mapEntry.getKey(), mapEntry.getValue());
}
}
System.out.println(formatter);
}
//Function for processing specific parts of the file.
public void processSpecificLines() {
}
//Reads the contents of the "data.txt".
public List<String> readFile() {
List<String> lines = new ArrayList<>();
try {
lines = Files.readAllLines(Paths.get(System.getProperty("user.dir"), "src", "main", "resources", "data.txt"));
} catch (IOException e) {
throw new RuntimeException(e);
}
return lines;
}
public static void main(String[] args) {
Application app = new Application();
app.run();
}
}

I tried googling the problem, but it seems like this either not possible or nobody has every thought about it, as I can't find anything about it.

The problem is not with the Formatter itself, but how you're storing the data before formatting it, using a HashMap which doesn't maintain any ordering. You could use a sortable collection instead, like:

List<Map.Entry<String, Integer>> sortedList = new ArrayList<>(stringMap.entrySet());
sortedList.sort(Map.Entry.<String, Integer>comparingByValue().reversed());

formatter.format("%20s %20s\n\n", "Word", "Occurrence");
for (Map.Entry<String, Integer> mapEntry : sortedList) {
    if (mapEntry.getKey().substring(0, 1).equals("1")) {
        formatter.format("%20s %20s\n", mapEntry.getKey(), mapEntry.getValue());
    } else {
        formatter.format("%20s %15s\n", mapEntry.getKey(), mapEntry.getValue());
    }
}