How to check whether name of the File is in a Specifi format??

[Ravi Kiran Va]

I am expecting the Filename to be in a specified format that is "Test_INT.NO1.<dd><MM><yy><HH><mm><ss>.txt"

for example

"Test_INT.NO1. 28 06 10 12 25 56.txt"

But Please let me know how do i check the File name has got a specific format or not ??

Please share your ideas on this .

Thanks in advance .

[Paul Sturrock]

Use a regular expression?

[David Newton]

I like Paul's answer.

[Raj S Kumar]

Filenames retrieved will be in the form of String. In my opinion, identifying the time format accurately is not always possible.

The only way I see is, to validate every parameter for its limits. such as 31 for <dd>, 12 for <MM> etc. This validation technique could help you to identify some parameters and factor the rest.

[Rob Spoor]

I'd prefer to use a DateFormat to check if the date is valid, rather than manually checking bounds. Using a DateFormat and its parse(String, ParsePosition) method you can even prevent any ParseExceptions:

DateFormat format = new SimpleDateFormat('Test_INT.NO1.'xxxx'.txt'); // the quotes make it literal text; fill in the xxxx yourself
format.setLenient(false); // to disallow February 30th etc
ParsePosition position = new ParsePosition(0);
Date date = format.parse(fileName, position);
if (date == null || position.getIndex() != fileName.length())
{
    System.out.println('invalid!");
}

That parse method returns null if the input is invalid. The other check also makes sure that the parsing consumes the entire input; parse methods usually allow trailing data; for instance, with "Test_INT.NO1. 28 06 10 12 25 56.txtabc" as input, the parse position's index will point at the a, allowing you to parse some more. Since we don't want to parse more or allow this trailing data the check ensures that the format will consume the entire text.