How to convert a String to a Date
In this blog post, I will be demonstrating how you can convert a String to a Date object. Consider the following code snippet:
public class StringToDate {
public static void main(String[] args) {
System.out.println("Enter a date:");
Scanner scanner = new Scanner(System.in);
String dateStr = scanner.nextLine();
System.out.println("Input date is "+dateStr);
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd-MM-yyyy");
try {
Date date = simpleDateFormat.parse(dateStr);
System.out.println("Date in date format is "+date);
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
scanner.close();
}
}
The input Date in String format is read using the Scanner class. The code uses the SimpleDateFormat class. This is a class that provides date formatting functions. In the constructor, you need to specify the format in which the input date is specified as a String. So in this case, I have specified “dd-MM-yyyy” which means the date will be in this format. Then, the parse method is invoked. This method is defined in the DateFormat class which is a super-class of SimpleDateFormat . This returns a Date object corresponding to the input String.
So if you run this code with the input as “08-09-2018“, it will print the following output:
Enter a date: 08-09-2018 Input date is 08-09-2018 Date in date format is Sat Sep 08 00:00:00 IST 2018
Note that the input date should match the format that is specified in the SimpleDateFormat constructor. Suppose we specify as input like this “08-Sep-18“, and if you run the code now, it will print the following:
Enter a date: 08-Sep-18 Input date is 08-Sep-18 java.text.ParseException: Unparseable date: "08-Sep-18" at java.text.DateFormat.parse(Unknown Source) at learnjava.dates.StringToDate.main(StringToDate.java:17)
The API documentation for SimpleDateFormat specifies the pattern Strings that you need to use for various date formats.
