How to get current timestamp in Scala as a string without spaces?

Question

I want to get for example a string of the current time: "20180122_101043". How can I do this?

I can create a val cal = Calendar.getInstance() but I'm not sure what to do with it after.

Answer 1

LocalDateTime is what you might want to use,

scala> import java.time.LocalDateTime
import java.time.LocalDateTime

scala> LocalDateTime.now()
res60: java.time.LocalDateTime = 2018-01-22T01:21:03.048

If you don't want default LocalDateTime format which is basically ISO format without zone info, you can apply DateTimeFormatter as below,

scala> import java.time.format.DateTimeFormatter
import java.time.format.DateTimeFormatter

scala> DateTimeFormatter.ofPattern("yyyy-MM-dd_HH:mm").format(LocalDateTime.now)
res61: String = 2018-01-22_01:21

Related resource - How to parse/format dates with LocalDateTime? (Java 8)

Answer 2

Calendar is not the best choice here. Use:

• java.util.Date + java.text.SimpleDateFormat if you have java 7 or below

  new SimpleDateFormat("YYYYMMdd_HHmmss").format(new Date)

• java.time.LocalDateTime + java.time.format.DateTimeFormatter for java 8+ LocalDateTime.now.format(DateTimeFormatter.ofPattern("YYYYMMdd_HHmmss"))

Answer 3

You can make use of Java 8 Date/Time API:

import java.time.LocalDateTime
import java.time.format.DateTimeFormatter

val format = "yyyyMMdd_HHmmss"

val dtf = DateTimeFormatter.ofPattern(format)

val ldt = LocalDateTime.of(2018, 1, 22, 10, 10, 43) // 20180122_101043

ldt.format(dtf)

To get the current time, use LocalDateTime.now().

Answer 4

You may use the java.time library. For instance:

import java.time
val s: String = time.LocalDateTime.now().toString
println(s)

gives 2021-04-23T14:13:01.163869. Then you need to manipulate the string, e.g.

time.LocalDateTime.now().toString.replace("T","_").replace("-","").replace(":","")

for 20210423_141639.769222.