Android: How can I Convert String to Date?
AndroidStringDateCastingAndroid Problem Overview
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
======> 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;
}
Android Solutions
Solution 1 - Android
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();
}
Solution 2 - Android
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy");
Date d = dateFormat.parse(datestring)
Solution 3 - Android
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MyClass
{
public static void main(String args[])
{
SimpleDateFormat formatter = new SimpleDateFormat("EEE MMM dd HH:mm:ss Z yyyy");
String dateInString = "Wed Mar 14 15:30:00 EET 2018";
SimpleDateFormat formatterOut = new SimpleDateFormat("dd MMM yyyy");
try {
Date date = formatter.parse(dateInString);
System.out.println(date);
System.out.println(formatterOut.format(date));
} catch (ParseException e) {
e.printStackTrace();
}
}
}
> here is your Date object date > and the output is :
Wed Mar 14 13:30:00 UTC 2018
14 Mar 2018
Solution 4 - Android
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
}
Solution 5 - Android
You can use java.time in Android now, either by using Android API Desugaring or importing the ThreeTenAbp.
With java.time enabled, you can do the same operations with less code and less errors.
Let's assume you are passing a String containing a datetime formatted in ISO standard, just as the currently accepted answer does.
Then the following methods and their usage in a main may show you how to convert from and to String:
public static void main(String[] args) {
String dtStart = "2010-10-15T09:27:37Z";
ZonedDateTime odt = convert(dtStart);
System.out.println(odt);
}
and
public static void main(String[] args) {
String dtStart = "2010-10-15T09:27:37Z";
OffsetDateTime odt = convert(dtStart);
System.out.println(odt);
}
will print the line
2010-10-15T09:27:37Z
when there are the corresponding methods
public static OffsetDateTime convert(String datetime) {
return OffsetDateTime.parse(datetime);
}
or
public static ZonedDateTime convert(String datetime) {
return ZonedDateTime.parse(datetime);
}
but of course not in the same class, that would not compile...
There's a LocalDateTime, too, but that would not be able to parse a zone or offset.
If you want to use custom formats for parsing or formatting output, you can utilize a DateTimeFormatter, maybe like this:
public static void main(String[] args) {
String dtStart = "2010-10-15T09:27:37Z";
String converted = ZonedDateTime.parse(dtStart)
.format(DateTimeFormatter.ofPattern(
"EEE MMM d HH:mm:ss zz uuuu",
Locale.ENGLISH
)
);
System.out.println(converted);
}
which will output
Fri Oct 15 09:27:37 Z 2010
For an OffsetDateTime, you would need to adjust the pattern a little:
public static void main(String[] args) {
String dtStart = "2010-10-15T09:27:37Z";
String converted = OffsetDateTime.parse(dtStart)
.format(DateTimeFormatter.ofPattern(
"EEE MMM d HH:mm:ss xxx uuuu",
Locale.ENGLISH
)
);
System.out.println(converted);
}
This will produce a (slightly) different output:
Fri Oct 15 09:27:37 +00:00 2010
That's because a ZonedDateTime considers named time zones with changing offsets (due to daylight saving times or anything similar) while an OffsetDateTime just knows an offset from UTC.
Solution 6 - Android
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.
Solution 7 - Android
String source = "24/10/17";
String[] sourceSplit= source.split("/");
int anno= Integer.parseInt(sourceSplit[2]);
int mese= Integer.parseInt(sourceSplit[1]);
int giorno= Integer.parseInt(sourceSplit[0]);
GregorianCalendar calendar = new GregorianCalendar();
calendar.set(anno,mese-1,giorno);
Date data1= calendar.getTime();
SimpleDateFormat myFormat = new SimpleDateFormat("20yy-MM-dd");
String dayFormatted= myFormat.format(data1);
System.out.println("data formattata,-->"+dayFormatted);