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I have a timestamp field which can be in any format (yyyy-MM-dd OR yyyy/MM/dd OR yyyy-MM-dd'T'HH:mm:ss ETC..) And I have no control to change it. I want to convert the incoming timestamp as it is to string so as to validate it against a RegEx.

I can find many solutions but all have a specific date format. Can this be done in generic way?

Zoe
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IllegalSkillsException
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    "I have a timestamp field which can be in *any format*" Well that's either **objectively not true** or **incredibly weird**. How do you expect to parse something that has no more predefined structure than a random collection numerals and characters? – Michael Jun 20 '18 at 10:29
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    being able to parse could mean many things... is date **01/02/03** **1st of Feb '03**, or **3rd of Feb '01**, or **2nd of Jan '03**, or **1st of Feb 1903**, or **1st of Feb 0003** ? – diginoise Jun 20 '18 at 10:48

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There's no standard way to do that. You can, however, use the commons-lang library, which offers DateUtils.html#parseDate:

Parses a string representing a date by trying a variety of different parsers.
The parse will try each parse pattern in turn. A parse is only deemed successful if it parses the whole of the input string. If no parse patterns match, a ParseException is thrown.

You would then be able to use it with multiple patterns in one call:

Date d = DateUtils.parseDate("2018/06/20", 
           "yyyy-MM-dd", "yyyy/MM/dd", "yyyy-MM-dd'T'HH:mm:ss");
System.out.println(d);
//And that prints Wed Jun 20 00:00:00 SAST 2018, matching on 2nd pattern
ernest_k
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  • This looks good but thing is `DateUtils.parseDate(String,String)`. In my case I am exposing an API which gets **timestamp** from the client and I need to validate if the incoming timestamp matches with **yyyy-MM-dd'T'HH:mm:ss** this format or not. So i do not know which format client will send (and I cannot force any restriction on this). I have a regex pattern to validate this but it again needs to convert the sent timestamp to respective string and then validaet against the regex. Not able to figure out the way out. – IllegalSkillsException Jun 21 '18 at 07:16