Java Cannot Format Given Object as Date

Question

I have a string with yyyyMMdd format and I want dd.MM.yyyy

I get this error with my code

java.lang.IllegalArgumentException: Cannot format given Object as a Date

String date = "20190226";
SimpleDateFormat sdf = new SimpleDateFormat("dd.MM.yyyy");                  
date = sdf.format(date);

Any help?

FYI, the terribly troublesome old date-time classes such as [`java.util.Date`](https://docs.oracle.com/javase/10/docs/api/java/util/Date.html), [`java.util.Calendar`](https://docs.oracle.com/javase/10/docs/api/java/util/Calendar.html), and `java.text.SimpleDateFormat` are now [legacy](https://en.wikipedia.org/wiki/Legacy_system), supplanted by the [*java.time*](https://docs.oracle.com/javase/10/docs/api/java/time/package-summary.html) classes built into Java 8 and later. See [*Tutorial* by Oracle](https://docs.oracle.com/javase/tutorial/datetime/TOC.html). — Basil Bourque, Feb 26 '19 at 18:16

score 5 · Answer 1 · edited Feb 26 '19 at 18:18

5

java.time

Java 8 and later versions you can use DateTimeFormatter.

Parsing text.

String str = "20190226";
DateTimeFormatter inputFormat = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDate dateTime = LocalDate.parse(str, inputFormat);

Generating text.

DateTimeFormatter outputFormat = DateTimeFormatter.ofPattern("dd.MM.yyyy");
System.out.println(dateTime.format(outputFormat));

26.02.2019

Most of the java.time functionality is back-ported to Java 6 & Java 7 in the ThreeTen-Backport project. Further adapted for earlier Android (<26) in ThreeTenABP. See How to use ThreeTenABP….

edited Feb 26 '19 at 18:18

Basil Bourque

303,325
100
852
1,154

answered Feb 26 '19 at 16:40

Prasann

1,263
2
11
18

Thanks @basil-bourque, for editing my answer to make it super neat and informative :) – Prasann Feb 26 '19 at 18:46
May also use `DateTimeFormatter.BASIC_ISO_DATE;` for the input format. – Ole V.V. Mar 25 '23 at 05:33

score 3 · Accepted Answer · answered Feb 26 '19 at 16:16

You can parse a java.util.Date into a String like this:

    String dateStr = "20190226";
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
    Date date = sdf.parse(dateStr);
    sdf = new SimpleDateFormat("dd.MM.yyyy");
    dateStr = sdf.format(date);

Java Cannot Format Given Object as Date

2 Answers2

java.time