How to compare two utc timestamps in Java?

Question

I am using the below method to generate a UTC timestamp and would like to compare it with another. I am using Apache Commons Lang library for this.

How can I compare the two timestamps and determine which one is bigger?

String msgPushedTimestamp = 2016-05-11T19:50:17.141Z
String logFileTimestamp = 2016-05-11T14:52:02.970Z

This is how I am generating the timestamp using Apache Commons Lang library.

String msgPushedTimestamp = FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", TimeZone.getTimeZone("UTC")).format(System.currentTimeMillis());

http://stackoverflow.com/questions/18915075/java-convert-string-to-timestamp — Simon Schüpbach, May 11 '16 at 20:06

score 5 · Accepted Answer · answered May 11 '16 at 20:24

5

You can compare them as strings because your date format (ISO 8601) is lexicographically comparable.

int compare = msgPushedTimestamp.compareTo(logFileTimestamp);
if (compare < 0) {
    // msgPushedTimestamp is earlier
} else if (compare > 0) {
    // logFileTimestamp is earlier
} else {
    // they are equal
}

answered May 11 '16 at 20:24

shmosel

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Perfect ! Thanks a ton. – Nital May 12 '16 at 15:26

score 1 · Answer 2 · answered May 11 '16 at 20:12

1

Have the class implement Comparable interface, you can use core Java's compareTo method. Works on timestamp in String type, as this is your case.

answered May 11 '16 at 20:12

user3207158

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I am actually using a Junit test. Can Junit actually implement Comparable interface ? – Nital May 11 '16 at 20:17
Not tried on this one. But I used interfaces and JUnit before and they worked fine. – user3207158 May 11 '16 at 20:24

How to compare two utc timestamps in Java?

2 Answers2