Convert string to date format in android

问题:

I'm trying to convert string to date format.I trying lot of ways to do that.But not successful. my string is "Jan 17, 2012". I want to convert this as " 2011-10-17". Could someone please tell me the way to do this? If you have any worked through examples, that would be a real help!

回答1:

public class Utils {

    public static void main(String[] args) {

        String mytime="Jan 17, 2012";
        SimpleDateFormat dateFormat = new SimpleDateFormat(
                "MMM dd, yyyy");

        Date myDate = null;
        try {
            myDate = dateFormat.parse(mytime);

        } catch (ParseException e) {
            e.printStackTrace();
        }

        SimpleDateFormat timeFormat = new SimpleDateFormat("yyyy-MM-dd");
        String finalDate = timeFormat.format(myDate);

        System.out.println(finalDate);
    }
}

回答2:

   String format = "yyyy-MM-dd";
   SimpleDateFormat sdf = new SimpleDateFormat(format, Locale.US);
   System.err.format("%30s %s\n", format, sdf.format(new Date(0)));
   sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
   System.err.format("%30s %s\n", format, sdf.format(new Date(0)));

Which produces this output when run in the PDT time zone:

                 yyyy-MM-dd 1969-12-31
                 yyyy-MM-dd 1970-01-01

For more info look at here

回答3:

I suggest using Joda Time, it's the best and simplest library for date / dateTime manipulations in Java, and it's ThreadSafe (as opposed to the default formatting classes in Java).

You use it this way:

// Define formatters:
DateTimeFormatter inputFormat = DateTimeFormat.forPattern("MMM dd, yyyy");
DateTimeFormatter outputFormat = DateTimeFormat.forPattern("yyyy-MM-dd");

// Do your conversion:
String inputDate = "Jan 17, 2012";
DateTime date = inputFormat.parseDateTime(inputDate);
String outputDate = outputFormat.print(date);
// or:
String outputDate = date.toString(outputFormat);
// or:
String outputDate = date.toString("yyyy-MM-dd");

// Result: 2012-01-17

It also provides plenty of useful methods for operations on dates (add day, time difference, etc.). And it provides interfaces to most of the classes for easy testability and dependency injection.

回答4:

Why do you want to convert string to string try to convert current time in milisecond to formated String, this method will convert your milisconds to a data formate.

 public static String getTime(long milliseconds)
{

         return DateFormat.format("MMM dd, yyyy", milliseconds).toString();
}

you can also try DATE FORMATE class for better understanding.

回答5:

You can't convert date from one format to other. while you are taking the date take you have take the date which ever format the you want. If you want the date in yyyy-mm-dd. You can get this by using following way.

            java.util.Calendar calc = java.util.Calendar.getInstance();

        int day = calc.get(java.util.Calendar.DATE);
        int month = calc.get(java.util.Calendar.MONTH)+1;
        int year = calc.get(java.util.Calendar.YEAR);

           String currentdate = year +"/"+month +"/"+day ;

回答6:

public static Date getDateFromString(String date) {

    Date dt = null;

    if (date != null) {
        for (String sdf : supportedDateFormats) {
            try {
                dt = new Date(new SimpleDateFormat(sdf).parse(date).getTime());
                break;
            } catch (ParseException pe) {
                pe.printStackTrace();
            }
        }
    }
    return dt;
}