package com.example.javamavenjunithelloworld;

public class HelloApp {

    static int DEFAULT_TIMES = 3;

    static int EXIT_STATUS_PARAMETER_NOT_UNDERSTOOD = 2;
    static int EXIT_STATUS_HELLO_FAILED = 4;

    public static void main(String[] args) {

        int times = DEFAULT_TIMES;
        if (args.length >= 1) {
            try {
                times = Integer.valueOf(args[0]);
            } catch (NumberFormatException e) {
                System.err.println("I don't understand the parameter you passed me. Is it a number? " +
                        "Parameter was: [" + args[0] + "]");
                System.exit(EXIT_STATUS_PARAMETER_NOT_UNDERSTOOD);
            }
        }

        Hello hi = new Hello();
        try {
            hi.setTimes(times);
        } catch (IllegalArgumentException e) {
            System.err.println("Something went wrong: " + e.getMessage());
            System.exit(EXIT_STATUS_HELLO_FAILED);
        }
        hi.sayHello(System.out);
    }

}

package com.example.javamavenjunithelloworld;

public class HelloApp {

    static int DEFAULT_TIMES = 3;

    static int EXIT_STATUS_PARAMETER_NOT_UNDERSTOOD = 2;
    static int EXIT_STATUS_HELLO_FAILED = 4;

    public static void main(String[] args) {

        int times = DEFAULT_TIMES;
        if (args.length >= 1) {
            try {
                times = Integer.valueOf(args[0]);
            } catch (NumberFormatException e) {
                System.err.println("I don't understand the parameter you passed me. Is it a number? " +
                        "Parameter was: [" + args[0] + "]");
               // System.exit(EXIT_STATUS_PARAMETER_NOT_UNDERSTOOD);
            }
        }

        Hello hi = new Hello();
        try {
            hi.setTimes(times);
        } catch (IllegalArgumentException e) {
            System.err.println("Something went wrong: " + e.getMessage());
            System.exit(EXIT_STATUS_HELLO_FAILED);
        }
        hi.sayHello(System.out);
    }

}

Update HelloApp.java