simpleDateFormat Problems and questions

[Justin Core]

Ok so here is the deal I am attempting to take data entered from the keyboard in the format MM dd yyyy with the whitespace. Example:12 28 1973

   GregorianCalendar now = new GregorianCalendar();
        Date today = now.getTime();
GregorianCalendar birthDayGregorian = new GregorianCalendar();
System.out.println("Please enter your birthdate in the format "+
                        " mm dd yyyy: ");

                birthDayString = scan.nextLine();
                SimpleDateFormat sdf = (SimpleDateFormat) new SimpleDateFormat( "MM dd yyyy" ).parseObject(birthDayString);
                Date bDay = sdf.parse(birthDayString);

                

                long seconds = today.getTime()/1000  - bDay.getTime()/1000;
                birthDayGregorian.getTime();
                bDay.getTime();
                System.out.println(""+sdf.format(bDay));
                System.out.println("Been alive for " + (double) seconds/(24 * 3600 * 365) + " years"); 

I am becoming very frustrated because I keep receiving this error
Exception in thread "main" java.text.ParseException: Format.parseObject(String) failed
at java.text.Format.parseObject(Format.java:228)
at spacetravel.Main.main(Main.java:51)
Java Result: 1

If someone could help me I would greatly appreciate it. Thank you

[Ernie Mcracken]

You should change out the .parseObject() method for just parse(). parse() returns a Date object, parseObject() returns object. Or you could cast the return from parse object.

String date = scanner.nextLine();
SimpleDateFormat sdf = new SimpleDateFormat("MM dd yyyy");
Date d = sdf.parse(date);

[Justin Core]

birthDayString = scan.nextLine();
                SimpleDateFormat sdf = (SimpleDateFormat) new SimpleDateFormat( "MM dd yyyy" );
                Date bDay = sdf.parse(birthDayString);

Exception in thread "main" java.text.ParseException: Unparseable date: ""
at java.text.DateFormat.parse(DateFormat.java:337)
at spacetravel.Main.main(Main.java:55)
Java Result: 1

When I change it to match my program it does not even let me enter the date but just immediately spits out the error

Any suggestions? Thank you for your reply

[Larry Frissell]

String birthDayString = "12 01 1956";
            SimpleDateFormat sdf = new SimpleDateFormat( "MM dd yyyy" );
            Date bDay = sdf.parse(birthDayString);

I am using the code above without an error.

[Justin Core]

Thank you the above code works for me as well.

Now when I change the code to accept a string from my scanner input.

It yields this error.
Exception in thread "main" java.text.ParseException: Unparseable date: ""
at java.text.DateFormat.parse(DateFormat.java:337)
at spacetravel.Main.main(Main.java:54)
Java Result: 1

                String birthDayString = scan.nextLine();
                SimpleDateFormat sdf = new SimpleDateFormat( "MM dd yyyy" );
                Date bDay = sdf.parse(birthDayString);

Thank you very much for your help. I greatly appreciate it

[Wouter Oet]

You do need to input a valid date in the correct format otherwise it will throw an Exception. And in your case you provided an empty String which is probably caused by just pressing enter instead of entering a date.

[Justin Core]

I am not sure I understand what you mean.
I need the scanner to read user input not a predefined string which I specify.
Thank you for your time.

[Ernie Mcracken]

Exception in thread "main" java.text.ParseException: Unparseable date: ""

This error means that you are passing an empty string to your parser, just as

Exception in thread "main" java.text.ParseException: Unparseable date: "201010101"

Would mean you had given it a garbage date.

Is your scanner working properly?, maybe you can try printing the birthDayString back to yourself after you read it in to confirm that it is as you were expecting.

[Justin Core]

I am at a loss here.
To try to see if the scanner is working properly I have edited my program as shown below.
The problem is in the out put it skips over entering the birthday all together The output looks like this

Please enter your name:
Justin c
Please enter your weight in lbs:
134
Please enter your birthdate in the format mm dd yyyy

BUILD SUCCESSFUL (total time: 4 seconds)

Thank you again for all of your help I appreciate it

        String traveler, birthDayString;
        int earthWeight;
        GregorianCalendar now = new GregorianCalendar();
        Date today = now.getTime();
        double earthAge;



        

        Scanner scan = new Scanner(System.in);
        
        GregorianCalendar birthDayGregorian = new GregorianCalendar();




                System.out.println("Please enter your name: ");
                traveler = scan.nextLine();
                System.out.println("Please enter your weight in lbs: ");
                earthWeight = scan.nextInt();

                System.out.println("Please enter your birthdate in the format mm dd yyyy");
                birthDayString = scan.nextLine();
                
                //SimpleDateFormat sdf = new SimpleDateFormat( "MM dd yyyy" );
                System.out.println(""+birthDayString);

[Ernie Mcracken]

Ok, so you need to change this line

earthWeight = scan.nextInt();  

to

earthWeight= Integer.parseInt(scan.nextLine());

I think basically when you use the nextInt() method of scanner and then call the nextLine() method later it's still stuck on the previous line where you typed in the weight.

[Justin Core]

IT WORKED !!
You sir are a godsend. As well as everyone else who replied.
Thank you very much.

[Ernie Mcracken]

Pleasure, maybe someone else can explain the whole Scanner and nextLine() issue better though.

[Campbell Ritchie]

Try here.