Get Date details (day, month, year) in GWT

问题

I need to get the day, month, year details from a Date value but getYear() is deprecated, gives year on 2 digits, and has problems with Y2K (2008 gives 108). The java doc recommends using java.util.calendar but it is not supported in GWT.

I want to avoid sending all the info back and forth between the server and client just to deal with dates.

Edit: ~~Calendar might be supported~~ Date handling functions should be implemented in GWT futur versions : http://code.google.com/p/google-web-toolkit/issues/detail?id=603

回答1:

Do not use those deprecated methods on Date class in GWT.

If you don't want to use third party Date implementations for GWT, You use a combination of DateTimeFormat along with string manipulation as a workaround for the time being, until GWT comes up with some better support for manipulating dates.

For date - 
DateTimeFormat.getFormat( "d-M-yyyy" ).format( new Date() ).split( "-")[0]

For month - 
DateTimeFormat.getFormat( "d-M-yyyy" ).format( new Date() ).split( "-")[1]

For year - 
DateTimeFormat.getFormat( "d-M-yyyy" ).format( new Date() ).split( "-")[2]

Edit- Similarly, avoid using new Date( yy, mm, dd ) has come inconsistencies depending on the browser and date range.

I have use a simple DateUtil Class to create and parse Date objects in GWT, maybe of some use to you -

(Warning: Very crude, and work in progress)

public class DateUtil
{
    private static final String D_M_YYYY = "d-M-yyyy";
    private static final String DATE_SEPARATOR = "-";

    public static Date getDate( Integer dd, Integer mm, Integer yyyy )
    {
        if ( dd == null || mm == null || yyyy == null )
            return null;

        Date retVal = null;
        try
        {
            retVal = DateTimeFormat.getFormat( D_M_YYYY ).parse( dd + DATE_SEPARATOR + mm + DATE_SEPARATOR + yyyy );
        }
        catch ( Exception e )
        {
            retVal = null;
        }

        return retVal;
    }

    public static String getDayAsString( Date date )
    {
        return ( date == null ) ? null : DateTimeFormat.getFormat( D_M_YYYY ).format( date ).split( DATE_SEPARATOR )[0];
    }

    public static String getMonthAsString( Date date )
    {
        return ( date == null ) ? null : DateTimeFormat.getFormat( D_M_YYYY ).format( date ).split( DATE_SEPARATOR )[1];
    }

    public static String getYearAsString( Date date )
    {
        return ( date == null ) ? null : DateTimeFormat.getFormat( D_M_YYYY ).format( date ).split( DATE_SEPARATOR )[2];
    }

    public static boolean isValidDate( Integer dd, Integer mm, Integer yyyy )
    {
        boolean isvalidDate = true;

        try
        {
            String transformedInput = DateTimeFormat.getFormat( D_M_YYYY ).format( getDate( dd, mm, yyyy ) );
            String originalInput = dd + DATE_SEPARATOR + mm + DATE_SEPARATOR + yyyy;

            isvalidDate = transformedInput.equals( originalInput );
        }
        catch ( Exception e )
        {
            isvalidDate = false;
        }

        return isvalidDate;
    }
}

回答2:

The workaround presented by Ashwin works and it's not that tricky. But I'd suggest using the date patterns instead of splitting:

For date - 
DateTimeFormat.getFormat( "d" ).format( new Date() )

For month - 
DateTimeFormat.getFormat( "M" ).format( new Date() )

For year - 
DateTimeFormat.getFormat( "yyyy" ).format( new Date() )

回答3:

You may just add 1900 to getYear() return value

回答4:

I don't think gwt will support Calendar in the future, may be it could support another date manipulation implementation. So, because the java recommendation about not using Date is not valid in Gwt and you have not any other option without importing a third party library, the right way is to use Date and ignore deprecation warnings.

来源：https://stackoverflow.com/questions/3201762/get-date-details-day-month-year-in-gwt

标签

datetime

gwt

date