java.util.date 到 String 使用 DateTimeFormatter

Question

How can I convert a java.util.Date to String using

 DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss")

The Date object which I get is passed

DateTime now = new DateTime(date);

Answer 1

If you are using Java 8, you should not use java.util.Date in the first place (unless you receive the Date object from a library that you have no control over).

In any case, you can convert a Date to a java.time.Instant using:

Date date = ...;
Instant instant = date.toInstant();

Since you are only interested in the date and time, without timezone information (I assume everything is UTC), you can convert that instant to a LocalDateTime object:

LocalDateTime ldt = instant.atOffset(ZoneOffset.UTC).toLocalDateTime();

Finally you can print it with:

DateTimeFormatter fmt = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss");
System.out.println(ldt.format(fmt));

Or use the predefined formatter, DateTimeFormatter.ISO_LOCAL_DATE_TIME .

System.out.println(ldt.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME));

Note that if you don't provide a formatter, calling ldt.toString gives output in standard ISO 8601 format (including milliseconds) - that may be acceptable for you.

Answer 2

DateTime dt = new DateTime(date);
DateTimeFormatter dtf = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss");
dt.toString(dtf)

Answer 3

java.util.Date date = new java.util.Date(System.currentTimeMillis());
Instant instant = date.toInstant();

LocalDateTime ldt = instant.atZone(ZoneId.systemDefault()).toLocalDateTime();

DateTimeFormatter fmt = DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss");
System.out.println(ldt.format(fmt));

Answer 4

since I asume you are using joda API: ergo, DateTimeFormatter is comming from org.joda.time.format.DateTimeFormatter :

 String dateTime = "02-13-2017 18:20:30";
// Format for input
DateTimeFormatter dtf = DateTimeFormat.forPattern("MM-dd-yyyy HH:mm:ss");
// Parsing the date
DateTime jodatime = dtf.parseDateTime(dateTime);

System.out.println(jodatime );

Answer 5

DateTimeFormatterOBJECT=DateTimeFormatter.ofPattern("DD/MMM/YYYY HH//MM/SS");

String MyDateAndTime= LocalDate.now().format(DateTimeFormatterOBJECT);

Answer 6

You can use the joda time formatter class:

import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
# conflict with import java.time.format.DateTimeFormatter;

final DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss")
            .withZone(DateTimeZone.UTC);

    System.out.println(DateTime.now().toString(formatter));