如何使用GWT将日期时间字符串转换为日期？

Question

In mysql, i have a field time_entered of type datetime (sample data: 2012-06-20 16:00:47). I also have a method, getTimeEntered(), that returns the value as String. I want to display the date in this format 2012-06-20 using DateTimeFormat from GWT.

here's my code:

String date = aprHeaderDW.getTimeEntered();
DateTimeFormat fmt = DateTimeFormat.getFormat("MM-dd-yyyy");
dateEntered.setText("" + fmt.format(date));

The problem is, the format method doesn't accept arguments as String. So if there's only a way I could convert the date from String to Date type, it could probably work. I tried typecasting but didn't work.

Answer 1

You should be able to just use DateTimeFormat .

Date date = DateTimeFormat.getFormat("yyyy-MM-dd HH:mm:ss").parse("2012-06-20 16:00:47");
String dateString = DateTimeFormat.getFormat("yyyy-MM-dd").format(date);

Otherwise there is a light-weight version of SimpleDateFormat that supports this pattern.

Date date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse("2012-06-20 16:00:47");

Answer 2

Hi There are two options.

The first is as it is already a string you could use a regular expression to modify the format.

The second is using a SimpleDateFormater you can parse the string to a date then back again. For example:

public class DateMerge {

    public static void main(String arg[]) 
    {
        String out = dateConvert("2012-06-20 16:00:47");
        System.out.println(out);
    }

    public static String dateConvert (String inDate)
    {
        try {
         DateFormat formatter ; 
         Date date ; 
          formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
          date = (Date)formatter.parse(inDate);
          formatter = new SimpleDateFormat("dd-MM-yyyy");
          String outDate = formatter.format(date);
          return outDate;

          } catch (ParseException e)
          {System.out.println("Exception :"+e);  }  


    return null;
    }
}

Answer 3

You may use like this.

    String date = "2012-06-20 16:00:47";

    SimpleDateFormat sf=new SimpleDateFormat("yyyy-MM-dd");
    String lDate=sf.format(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(date));

    System.out.println(lDate);

Output:

2012-06-20

Answer 4

After trying a lot of times I came up with a solution, based on @Keppil and adding my own code.

Here's Keppil's suggested solution for converting String datetime into Date type:

Date date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse("2012-06-20 16:00:47");

...but my second requirement is to display just the date like 2012-06-20. Even though I removed HH:mm:ss, it still displayed the time like this 2012-06-20 00:00:00.

Here's my final solution:

Date date = null;
String d = rs.getString(SQL_CREATION_TIME); // assigns datetime value from mysql

// parse String datetime to Date
try {
date = new SimpleDateFormat("yyyy-MM-dd").parse(d);
System.out.println("time entered: "+  date);
} catch (ParseException e) { e.printStackTrace(); }

// format the Date object then assigns to String
Format formatter;
formatter = new SimpleDateFormat("yyyy-MM-dd");
String s = formatter.format(date);