CODEWITHSUNDEEP
javaandroidsimpledateformat
Muhammad Rafi Bahrur Rizki
Muhammad Rafi Bahrur Rizki

Reputation: 451

How to check time SImpleDateFormat?

I have 2 times SimpleDateFormat :

  1. 2020-11-23T21:17:03.039023Z
  2. 2020-11-23T21:17:03Z

How to check if the time use "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'" or "yyyy-MM-dd'T'HH:mm:ss'Z'" ?

example :

if ("2020-11-23T21:17:03.039023Z".contentEquals("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'")) {
    Log.e("TAG", "true");
} else {
    Log.e("TAG", "false");
}

Upvotes: 1

Views: 82

Answers (2)

Arvind Kumar Avinash
Arvind Kumar Avinash

Reputation: 79095

You can parse the date-time string to Instant and check if the fraction of second is greater than 0.

import java.time.DateTimeException;
import java.time.Instant;

public class Main {
    public static void main(String[] args) {
        // Test
        System.out.println(isTagEnabled("2020-11-23T21:17:03.039023Z"));
        System.out.println(isTagEnabled("2020-11-23T21:17:03Z"));
    }

    static boolean isTagEnabled(String strDateTime) {
        boolean enbaled = false;
        try {
            if (Instant.parse(strDateTime).getNano() > 0) {
                enbaled = true;
            }
        } catch (DateTimeException e) {
            e.printStackTrace();
        }
        return enbaled;
    }
}

Output:

true
false

Based on this, you can write your code as

if (isTagEnabled("2020-11-23T21:17:03.039023Z")) {
    Log.e("TAG", "true");
} else {
    Log.e("TAG", "false");
}

Note that the date-time API of java.util and their formatting API, SimpleDateFormat are outdated and error-prone. I suggest you should stop using them completely and switch to the modern date-time API.

Learn more about the modern date-time API at Trail: Date Time. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project.

Upvotes: 1

Tim Biegeleisen
Tim Biegeleisen

Reputation: 521457

You probably want String#matches here with an appropriate regex pattern:

String dt = "2020-11-23T21:17:03.039023Z";
String regex = "\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}\\.\\d{6}Z";
if (dt.matches(regex)) {
Log.e("TAG", "true");
}
else {
    Log.e("TAG", "false");
}

But note that the above does not actually do any validation on the input, but rather just detects the general pattern, and distinguishes from the version with no millisecond/microsecond precision.

Upvotes: 2

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