Cannot format given object as a Date using LocaleDateTime.now-CodePudding

Why do I get an error when I try using this code:

get() {
    current = LocalDateTime.now()
    val sharedPreferences = ctx.getSharedPreferences(COMMON_MANAGER, Context.MODE_PRIVATE)
    val formatter = SimpleDateFormat("yyyy/MM/dd")
    val formatted = formatter.format(current)
    return sharedPreferences.getString("currentDate", formatted)
}

It says cannot format given object a date. I have a value of "2022-01-10T14:55:18.523" in the variable current.

EDIT

I tried using this code :

current = LocalDateTime.now()
        val formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd")
        val formatted = formatter.format(current)
        return sharedPreferences.getString("currentDate", formatted)

But it gives me an error like so:

CodePudding user response：

Replace DateTimeFormatter instead of SimpleDateFormat

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

class Scratch {
    public static void main(String[] args) {
        LocalDateTime now = LocalDateTime.now();
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd");
        String result = formatter.format(now);
        System.out.println(result);
    }
}

CodePudding user response：

You are experiencing this error because you are using a java.text.SimpleDateFormat to format a java.time.LocalDateTime.

I don't think that's possible, but even if it is you will be best adviced not to mix those two apis.

You should instead use a DateTimeFormatter and due the pattern you have used in your SimpleDateFormat("yyyy/MM/dd") I would replace the lines

val formatter = SimpleDateFormat("yyyy/MM/dd")
val formatted = formatter.format(current)

with these

val formatter = DateTimeFormatter.ofPattern("uuuu/MM/dd")
val formatted = current.format(formatter)