How to check whether given string converted to long is EpochMills or not?

Question

Hi Is there any way to check whether the given string is epoch millis or not

The below code from java.time package converts to EpochMillis.

I am looking for isEpochMillis to return a boolean condition.

Is there any ready made api from apache commons or google guava to check this ? just like isDouble isLong etc...

/**
     * Obtains an instance of {@code Instant} using milliseconds from the
     * epoch of 1970-01-01T00:00:00Z.
     * <p>
     * The seconds and nanoseconds are extracted from the specified milliseconds.
     *
     * @param epochMilli  the number of milliseconds from 1970-01-01T00:00:00Z
     * @return an instant, not null
     * @throws DateTimeException if the instant exceeds the maximum or minimum instant
     */
    public static Instant ofEpochMilli(long epochMilli) {
        long secs = Math.floorDiv(epochMilli, 1000);
        int mos = (int)Math.floorMod(epochMilli, 1000);
        return create(secs, mos * 1000_000);
    }

Huh? Any integer is a valid timestamp. Zero is the epoch itself. Minus a billion billion billion is... quite a long time ago. — Michael, Jul 31 '19 at 16:05

score 0 · Answer 1 · answered Jul 31 '19 at 16:07

0

Any positive whole number is theoretically valid. You can add constraints based on your own knowledge of the domain. For example: no timestamps in the future, hence all numbers greater than Instant.now().toEpochMillis() are invalid.

answered Jul 31 '19 at 16:07

Issa Khoury

44
3

I know these things, I just need ready made api with apache commons or guava to check whether passed long is parsable or not – user3190018 Jul 31 '19 at 18:14
Is there any ready made api from apache commons or google guava to check this ? – user3190018 Jul 31 '19 at 21:11
AFAIK no, as mentioned in other comments you have Long.parseLong to verify that the string is a number, and then compare it with Instant.now(). This can be easily wrapped in a utility class in your project. – Issa Khoury Aug 01 '19 at 17:47

user1478293 · Answer 2 · 2019-07-31T16:22:00.007

0

As the javadoc says, epochMilli is number of milliseconds since 1970-01-01. All long values are valid epochMillis. It comes down to down to which dates you allow. That will then be your range.

-2 would result in 1969-12-31T23:59:59.998Z.

edited Jul 31 '19 at 16:22

answered Jul 31 '19 at 16:08

user1478293

46
1
5

I know these things, I just need ready made api with apache commons or guava to check whether passed long is parsable or not – user3190018 Jul 31 '19 at 18:14
1

Then use `Long.parse(epochMillisInString, 10)` – Olivier Grégoire Jul 31 '19 at 19:05
Is there any ready made api from apache commons or google guava to check this ? – user3190018 Jul 31 '19 at 21:11
If you really want to use for example Apache Commons, you could use NumberUtils. http://commons.apache.org/proper/commons-lang/javadocs/api-3.9/org/apache/commons/lang3/math/NumberUtils.html – user1478293 Jul 31 '19 at 22:32

score 0 · Answer 3 · answered Aug 04 '19 at 17:02

0

There is not, but here is an implementation of that method:

public static boolean isEpochMillis(long epochMilli) { 
  return true; 
}

Of course, you might find that this method is unnecessary, now that you see its implementation.

answered Aug 04 '19 at 17:02

Louis Wasserman

191,574
25
345
413

How to check whether given string converted to long is EpochMills or not?

3 Answers3