将字符串转换为日期类型

Question

I want to convert string to date format, but the following way didn't work.

It yields null for birth .

---

Date  birth;
try {
   DateFormat formatter ; 
   formatter = new SimpleDateFormat("dd-MMM-yyyy");
   birth = (Date)formatter.parse(birthDate);   // birtDate is a string 
} catch (ParseException e) {
    System.out.println("Exception :"+e);
}  

Answer 1

Your answer is right on the money. I put it in a full program and tested it.
It now prints out

Default date format Fri Mar 30 00:00:00 CDT 2012
Our SimpleDateFormat 30-Mar-2012
Our SimpleDateFormat with all uppercase 30-MAR-2012

Here are some tips:

• Make sure that you are including the correct imports. Depending on what is in your classpath, you may have accidentally imported java.sql.Date or some other rogue import.
• Try printing the contents of birthDate before entering the try block and verify that it really contains a string of format dd-MMM-yyyy

-

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class BirthDate {

    public static void main(String[] args) {
        Date birth = null;
        String birthDate = "30-MAR-2012";
        DateFormat formatter = null;
        try {
            formatter = new SimpleDateFormat("dd-MMM-yyyy");
            birth = (Date) formatter.parse(birthDate); // birtDate is a string
        }
        catch (ParseException e) {
            System.out.println("Exception :" + e);
        }
        if (birth == null) {
            System.out.println("Birth object is still null.");
        } else {
            System.out.println("Default date format " + birth);
            System.out.println("Our SimpleDateFormat " + formatter.format(birth));
            System.out.println("Our SimpleDateFormat with all uppercase " + formatter.format(birth).toUpperCase());
        }
    }
}

Answer 2

Your code works fine. If you care to use Joda Time you can use this. You can go through the documentation to unleash the complete functionality in case you plan to use the time for DB testing and stuff.

import org.joda.time.DateTime;
DateTime dt = new DateTime("YYYY-MM-DD");//new DateTime("2012-03-30")
System.out.println(dt);