Converting date into day of year

Question

I'm trying to write a program that prints the day of the year, given the date is in "month day year" form ie: 1 1 05, is day number 1 and 12 25 05 is day number 359.
the program should also check for a leap year.
I found this in a Google search and it's rediculously close to what i'm looking to achive, but instead of "today's date" i need it to read a day that was entered using Scanner or JOptionPane... and it would have to be in the above format when being entered.
import java.util.Calendar;
public class CalendarExample
public static void main(String[] args)
Calendar cal = Calendar.getInstance();
int day = cal.get(Calendar.DATE);
int month = cal.get(Calendar.MONTH) + 1;
int year = cal.get(Calendar.YEAR);
int dow = cal.get(Calendar.DAY_OF_WEEK);
int dom = cal.get(Calendar.DAY_OF_MONTH);
int doy = cal.get(Calendar.DAY_OF_YEAR);
System.out.println("Current Date: " + cal.getTime());
System.out.println("Day: " + day);
System.out.println("Month: " + month);
System.out.println("Year: " + year);
System.out.println("Day of Week: " + dow);
System.out.println("Day of Month: " + dom);
System.out.println("Day of Year: " + doy);
this if for a begining level java class, and I have no idea where to get started. Any help would be appreciated.

Answer 1

End result
import java.util.Scanner;
public class dayoftheYear
     public static void main(String[] args)
          //Declare variables
          int day, month, year, doy=0, Jan=31, Feb=28, Febleap=29, Mar=31;
          int Apr=30, May=31, Jun=30, Jul=31, Aug=31, Sep=30, Oct=31, Nov=30, Dec=31;
          //Description
          System.out.println("************************************************************");
          System.out.println("This application will"
                              + " use input for month and day "
                              + "\nto determine what day of the year "
                              + "it is.  It will also check "
                              + "\nto see if it's a leap year and adjust  "
                              + "\nthe day of the year accordingly");
          System.out.println("************************************************************");
          System.out.println();
          //Create a Scanner object to read input.
          Scanner keyboard = new Scanner(System.in);
          //Input and print number.
          System.out.print("Input month: ");
          //Assign input
          month = keyboard.nextInt();
          //Input and print number.
          System.out.print("Input day: ");
          //Assign input
          day = keyboard.nextInt();
          //Input and print number.
          System.out.print("Input year: ");
          //Assign input
          year = keyboard.nextInt();
          //If leapyear, Feb has 29 days
          if(isLeap(year)==1)
                    Feb =29;
          //Determine day of year
          switch (month)
                     case 1:  doy=day; break;
                     case 2:  doy=Jan+day; break;
                  case 3:  doy=Jan+Feb+day; break;
                  case 4:  doy=Jan+Feb+Mar+day; break;
                  case 5:  doy=Jan+Feb+Mar+Apr+day; break;
                  case 6:  doy=Jan+Feb+Mar+Apr+May+day; break;
                  case 7:  doy=Jan+Feb+Mar+Apr+May+Jun+day; break;
                  case 8:  doy=Jan+Feb+Mar+Apr+May+Jun+Jul+day; break;
                  case 9:  doy=Jan+Feb+Mar+Apr+May+Jun+Jul+Aug+day; break;
                  case 10: doy=Jan+Feb+Mar+Apr+May+Jun+Jul+Aug+Sep+day; break;
                  case 11: doy=Jan+Feb+Mar+Apr+May+Jun+Jul+Aug+Sep+Oct+day; break;
                  case 12: doy=Jan+Feb+Mar+Apr+May+Jun+Jul+Aug+Sep+Oct+Nov+day; break;  //hey! that looks pretty!
                  default: System.out.println("Invalid month.");break;
          //Print day of year
          System.out.println("Day of year: " +doy);
          }//endmain
          //beginmethod
          public static int isLeap(int y)
               //Assuming Y2K compliancy is not an issue, all dates will be based in the year 2000+
               y += 2000;
               //Check if year is a leap year
               if(y%4==0&&y%100!=0)
                    return 1;      //yes
               else if(y%100==0&&y%400==0)
                    return 1;     //yes
               else
                    return 0;     //no
          }//endmethod
}