Question

Create a simple Java class for a Month object with the following requirements:

 This program will have a header block comment with your name, the course and section, as well as a brief description of what the class does.
 All methods will have comments concerning their purpose, their inputs, and their outputs
 One integer property: monthNumber (protected to only allow values 1-12). This is a numeric representation of the month (e.g. 1 represents January, 2 represents February, etc.)
 A constructor that takes no arguments, and sets the monthNumber to 1.
 Add a second constructor that takes in an integer argument to set the initial monthNumber for the new Month object. Use data protection to prevent the user from entering a number less than 1 or greater than 12. When a non-valid input is entered, throw a new IllegalArgumentException.
 A setMonth() method that takes an integer and uses data protection to prevent the user from entering a number less than 1 or greater than 12. Also throw an IllegalArgumentException if an illegal value is entered.
 A getMonth() method that returns the monthNumber as an integer.
 Add a String array property that holds the values of the month names (e.g. monthNames[3] would hold the value “March”). Remember, you can leave the 0th index blank/null
 Add a toString() method to use the monthNumber property to return the name of the month as a String. Use the private global String array with the names of the months in it to return the proper String based on the monthNumber.
 Add an equals() method that takes in a month object and returns a boolean based on the values of each object’s monthNumber
 Add a compareTo() method that takes in a month object and returns a negative number if the called object is smaller than the passed in object, a positive number if the called object is bigger than the passed in object, and zero (0) if the two objects are equivalent.

Answer 1

Following is the answer:

Months.java

public class Months {
    private int monthNumber;
    private String[] monthNames = {"null", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};

    Months(){
        this.monthNumber = 1;
    }

    Months(int monthNumber){
        try {
            if(monthNumber > 0 && monthNumber < 13){
                this.monthNumber = monthNumber;
            }else {
                throw new IllegalArgumentException();
            }
        }catch (IllegalArgumentException e){
            System.out.println("Invalid month");
        }
    }

    public int getMonthNumber() {
        return monthNumber;
    }

    public void setMonthNumber(int monthNumber) {
        try {
            if(monthNumber > 0 && monthNumber < 13){
                this.monthNumber = monthNumber;
            }else {
                throw new IllegalArgumentException();
            }
        }catch (IllegalArgumentException e){
            System.out.println("Invalid month");
        }
    }

    @Override
    public String toString() {
        return monthNames[this.monthNumber];
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Months months = (Months) o;
        return monthNumber == months.monthNumber;
    }

    public int compareTo(Object o){
        return this.compareTo(o);
    }

}

MonthsMain.java

public class MonthsMain {
    public static void main(String[] args) {
        Months months = new Months(12);
        System.out.println(months.toString());
    }
}