Kotlin - SimpleDateFormat parsing takes infinite time

Question

I am trying to parse date string with SimpleDateFormat which never stops nor gives any exception. Please see the code below,

fun getDate(dateStr: String) {

    try {
        /** DEBUG dateStr = '2006-04-16T04:00:00Z' **/
        val formatter = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", Locale.ENGLISH)
        val mDate = formatter.parse(dateStr) // this never ends while debugging
    } catch (e: Exception){
        Logger.e("Error $e") // this never gets called either
    }
}

What can be the possible issue?

Note: I am using,

Android Studio: 3.4.1, Kotlin version: 1.3.31, Min SDK: 23, Target SDK: 28, Compile SDK: 28

java.text.ParseException: Unparseable date: "2006-04-16T04:00:00Z" Its giving error — Pavya, Jun 20 '19 at 04:11
Its giving parse Exception directly .. Use `yyyy-MM-dd'T'HH:mm:ss'Z'` cause your date does not have value for ZONE .. Use `DateTime` API of Java 8 or some backport like `ThreeTenBP` for date operations.. — ADM, Jun 20 '19 at 04:16
There's a `'` missing before and after `Z`. Shouldn't it be like this: `yyyy-MM-dd'T'HH:mm:ss'Z'` in this code? — SaadAAkash, Jun 20 '19 at 04:18
Possible sort of duplicate of [ISO 8601 String to Date/Time object in Android](https://stackoverflow.com/questions/3941357/iso-8601-string-to-date-time-object-in-android) — Ole V.V., Jun 20 '19 at 08:29

score 5 · Accepted Answer · answered Jun 20 '19 at 04:15

5

Use below function

fun getDate(dateStr: String) {
        try {
            /** DEBUG dateStr = '2006-04-16T04:00:00Z' **/
            val formatter = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ENGLISH)
            val mDate = formatter.parse(dateStr) // this never ends while debugging
            Log.e("mDate", mDate.toString())
        } catch (e: Exception){
            Log.e("mDate",e.toString()) // this never gets called either
        }
    }

answered Jun 20 '19 at 04:15

Pavya

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Wrong. The `Z` is an offset (of 0) form UTC and needs to be parsed as such (not as a literal), or you will get wrong times on the vast majority of JVMs. – Ole V.V. Jun 24 '19 at 11:31

score 2 · Answer 2 · answered Jun 20 '19 at 04:26

2

Your date format is incorrect. It should be as shown below

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");

Notice the enclosing ' with Z. You are missing that in your date format.

answered Jun 20 '19 at 04:26

Vivek Mishra

5,669
9
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Interesting it solved my issue. But I wonder why there was no exception happens when I debugged. Thanks a lot. – Sazzad Hissain Khan Jun 20 '19 at 04:59
Glad that I can help – Vivek Mishra Jun 20 '19 at 05:00
1

Not correct. `Z` in the datetime string is an offset (of 0) from UTC and must be parsed as such (not as a literal), or you will get incorrect results (on the majority of JVMs). – Ole V.V. Jun 20 '19 at 08:27
1

Correction: it happens to work correctly on Android devices that have their time zone set to UTC. I believe they are not that many. – Ole V.V. Jun 20 '19 at 09:05

score 0 · Answer 3 · answered Mar 17 '21 at 19:53

I had a similar issue and my problem was that I was importing the wrong ParseException. You need to make sure you are importing the java.text parse exception.

Check the import code at the top of your file.

CORRECT ParseException

import java.text.ParseException

INCORRECT ParseException

import android.net.ParseException //Android example

Your date formats weren't lining up either, so of course that also needed to be fixed. But ideally you want the try/catch block to stop your program from crashing if the date strings are ever bad, so it's a good idea to test it with bad data.

score 0 · Answer 4 · answered May 26 '21 at 06:40

The timezone here actually is using ISO 8601 format. To correctly parse this by Java SimpleDateFormat you should use the below pattern: "yyyy-MM-dd'T'HH:mm:ssX"

Here X means time zone in ISO 8601 format. See https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

Kotlin - SimpleDateFormat parsing takes infinite time

4 Answers4