Extract date from String java

Question

I have a String with several dates, for example:

[20-Jul-2012 5:11:36,670 UTC PM, 20-Jul-2012 5:11:36,683 UTC PM]

How do I read this string and extract each date? I'm using the SimpleDateFormat class to create a regex.

SimpleDateFormat format2 = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss,SSS z a");

I've tried:

I've just did, to get the first one and it changes the format and the timezone:

ParsePosition parsePos = new ParsePosition(1);
SimpleDateFormat format2 = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss,SSS z a");
System.out.println(format2.parse(entry.getValue().toString(), parsePos)) ;

Output: Fri Jul 20 06:11:36 BST 2012

Answer 1

You can try:

 parsePos = new ParsePosition(1);
 while((date = format2.parse(yourString, parsePos)!=null){
      //use date
 }

Answer 2

java.time

The question uses SimpleDateFormat which was the correct thing to do in 2012. In Mar 2014, the java.util date-time API and their formatting API, SimpleDateFormat were supplanted by the modern Date-Time API . Since then, it is strongly recommended to stop using the legacy date-time API.

Solution using the modern date-time API :

import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
import java.util.stream.Stream;

class Main {
    public static void main(String[] args) {
        DateTimeFormatter parser = DateTimeFormatter.ofPattern("d-MMM-uuuu h:m:s,SSS VV a", Locale.ENGLISH);
        Stream.of(
                    "20-Jul-2012 5:11:36,670 UTC PM",
                    "20-Jul-2012 5:11:36,683 UTC PM"
            )
            .map(s -> ZonedDateTime.parse(s, parser))
            .forEach(System.out::println);
    }
}

Output :

2012-07-20T17:11:36.670Z[UTC]
2012-07-20T17:11:36.683Z[UTC]

ONLINE DEMO

Learn more about the modern Date-Time API from Trail: Date Time .