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Android, How can I Convert String to Date?

Posted by: admin November 29, 2017 Leave a comment

Questions:

I store current time in database each time application starts by user.

Calendar c = Calendar.getInstance();
    String str = c.getTime().toString();
    Log.i("Current time", str);

In database side, I store current time as string (as you see in above code). Therefore, when I load it from database, I need to cast it to Date object. I saw some samples that all of them had used “DateFormat”. But my format is exactly as same as Date format. So, I think there is no need to use “DateFormat”. Am I right?

Is there anyway to directly cast this String to Date object? I want to compare this stored time with current time.

Thanks

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update

Thanks dear guys. I used following code:

private boolean isPackageExpired(String date){
        boolean isExpired=false;
        Date expiredDate = stringToDate(date, "EEE MMM d HH:mm:ss zz yyyy");        
        if (new Date().after(expiredDate)) isExpired=true;

        return isExpired;
    }

    private Date stringToDate(String aDate,String aFormat) {

      if(aDate==null) return null;
      ParsePosition pos = new ParsePosition(0);
      SimpleDateFormat simpledateformat = new SimpleDateFormat(aFormat);
      Date stringDate = simpledateformat.parse(aDate, pos);
      return stringDate;            

   }
Answers:

From String to Date

String dtStart = "2010-10-15T09:27:37Z";  
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");  
try {  
    Date date = format.parse(dtStart);  
    System.out.println(date);  
} catch (ParseException e) {
    e.printStackTrace();  
}

From Date to String

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");  
try {  
    Date date = new Date();  
    String dateTime = dateFormat.format(date);
    System.out.println("Current Date Time : " + dateTime); 
} catch (ParseException e) {
    e.printStackTrace();  
}

Questions:
Answers:
SimpleDateFormat dateFormat = new SimpleDateFormat("DD-MM-YYYY");
Date d = dateFormat.parse(datestring)

Questions:
Answers:

using SimpleDateFormat or DateFormat class through

for e.g.

try{
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy"); // here set the pattern as you date in string was containing like date/month/year
Date d = sdf.parse("20/12/2011");
}catch(ParseException ex){
    // handle parsing exception if date string was different from the pattern applying into the SimpleDateFormat contructor
}

Questions:
Answers:

It could be a good idea to be careful with the Locale upon which c.getTime().toString(); depends.

One idea is to store the time in seconds (e.g. UNIX time). As an int you can easily compare it, and then you just convert it to string when displaying it to the user.