updated code

package com.message.logs;

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Stack;

public class Main {
    public static void main(String[] args) {

        String fileLocation = null;
        boolean repeat = false;
        boolean isCommand = false;
        String arg;
        String command = null;
        String content = null;
        if(args.length == 0 && System.in == null) {
            help("Please enter a file with --file", true);
        }
        for (int i = 0; i < args.length; i++) {
            arg = args[i];
            if(isCommand) {
                isCommand = false;
                continue;
            }
            while(arg.substring(0,1).contains("-")) {
                arg = arg.substring(1);
                command = arg;
                isCommand = true;
            }

            if(!isCommand) continue;

            if(args.length <= i + 1) {
                isCommand = false;
            }
            else content = args[i + 1];

            // ADD ANY ARGUMENTS HERE
            if(command.contains("file")) {
                assert content != null;
                fileLocation = content;
            }
            else if(command.contains("repeat")) {
                repeat = true;
                isCommand = false;
            }
            else if(command.contains("help") || command.contains("h")) {
                help(true);
            }
            else {
                help("Unknown arguments : --" + command, true);
            }
        }
        if(fileLocation == null && System.in == null) {
            System.out.println("Please enter a file with --file");
            System.exit(1);
        }

        try
        {
            BufferedReader br;
            if(fileLocation != null) {
                br = new BufferedReader(new FileReader(fileLocation));
            }
            else {
                br = new BufferedReader((new InputStreamReader(System.in, StandardCharsets.UTF_8)));
            }
            String line;
            Stack<String> users = new Stack<>();
            int succeeded = 0;
            int failed;
            int total = 0;

            if(!br.ready()) {
                help("Cannot read the file", true);
            }
            while((line=br.readLine())!=null)
            {
                if(!line.contains("sshd[")) continue;
                String[] arr = Arrays.stream(line.split(" ")).filter(s -> !s.isEmpty()).toArray(String[]::new);
                if(arr.length < 11) continue;
                String success = arr[5];
                String failure = arr[8];
                String user = arr[10];
                if(!success.contains("Accepted")) {
                    if(failure.contains("failure")) {
                        total++;
                    }
                    continue;
                }
                total++;
                succeeded++;

                if(!repeat) {
                    if (users.contains(user)) continue;
                    users.add(user);
                }

                System.out.println((total + 1) + " " + user);
            }

            failed = total - succeeded;
            System.out.println();
            System.out.println("Total :");
            if(!repeat) System.out.println(users.size() + " unique IP SSH logins succeeded");
            System.out.println(succeeded + " SSH logins succeeded");
            System.out.println(failed + " SSH logins failed");
            System.out.println(total + " total SSH logins");
            System.exit(0);
        }
        catch(IOException e)
        {
            System.out.println("Cannot find this file");
            System.exit(1);
        }
    }

    static void help(boolean exit) {
        help("{{nothing}}", exit);
    }

    static void help(String additionalMessage, Boolean exit) {
        if(!additionalMessage.contains("{{nothing}}")) {
            System.out.println(additionalMessage);
            System.out.println();
        }
        System.out.println("Arguments :");
        System.out.println(" --file (required) : The document to analyse");
        System.out.println(" --repeat : Ignore if a IP has already been shown");
        System.out.println(" --help : Return help about the command");
        System.out.println();
        if(exit) System.exit(0);
    }
}