Will Will - 3 months ago 9
Java Question

Converting a Date object to a calendar object

So I get a date attribute from an incoming object in the form:

Tue May 24 05:05:16 EDT 2011


I am writing a simple helper method to convert it to a calendar method, I was using the following code:

public static Calendar DateToCalendar(Date date )
{
Calendar cal = null;
try {
DateFormat formatter = new SimpleDateFormat("yyyyMMdd");
date = (Date)formatter.parse(date.toString());
cal=Calendar.getInstance();
cal.setTime(date);
}
catch (ParseException e)
{
System.out.println("Exception :"+e);
}
return cal;
}


To simulate the incoming object I am just assigning the values within the code currently using:

private Date m_lastActivityDate = new Date();


However this is givin me a null pointer once the method reaches:

date = (Date)formatter.parse(date.toString());

Answer

Here's your method:

public static Calendar DateToCalendar(Date date){ 
  Calendar cal = Calendar.getInstance();
  cal.setTime(date);
  return cal;
}

Everything else you are doing is both wrong and unnecessary.

BTW, Java Naming conventions suggest that method names start with a lower case letter, so it should be: dateToCalendar


OK, let's milk your code, shall we?

DateFormat formatter = new SimpleDateFormat("yyyyMMdd");
date = (Date)formatter.parse(date.toString()); 

DateFormat is used to convert Strings to Dates (parse()) or Dates to Strings (format()). You are using it to parse the String representation of a Date back to a Date. This can't be right, can it?

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