How to parse dates in multiple formats using SimpleDateFormat

Question

I am trying to parse some dates that are coming out of a document. It would appear users have entered these dates in a similar but not exact format.

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Answer 1

Using DateTimeFormatter it can be achieved as below:

import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAccessor;
import java.util.Date;
import java.util.TimeZone;

public class DateTimeFormatTest {

    public static void main(String[] args) {

        String pattern = "[yyyy-MM-dd[['T'][ ]HH:mm:ss[.SSSSSSSz][.SSS[XXX][X]]]]";
        String timeSample = "2018-05-04T13:49:01.7047141Z";
        SimpleDateFormat simpleDateFormatter = new SimpleDateFormat("dd/MM/yy HH:mm:ss");
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
        TemporalAccessor accessor = formatter.parse(timeSample);
        ZonedDateTime zTime = LocalDateTime.from(accessor).atZone(ZoneOffset.UTC);

        Date date=new Date(zTime.toEpochSecond()*1000);
        simpleDateFormatter.setTimeZone(TimeZone.getTimeZone(ZoneOffset.UTC));
        System.out.println(simpleDateFormatter.format(date));       
    }
}

Pay attention at String pattern, this is the combination of multiple patterns. In open [ and close ] square brackets you can mention any kind of patterns.