Get Month from Date in Log File

sbowde4 :

I have an input String formatted like this.

96.7.4.14 - - [24/Apr/2011:04:20:11 -0400] "GET /cat.jpg HTTP/1.1" 200 1243

I know how to get the entire date from the string, but what would be the best way to just extract the three letter month code?

Yassin Hajaj :

You can use the following regex to extract the three letters month

(?<=\d{2}\/)(\w{3})(?=\/\d{4})

What it does basically is lookbehind to find two digits and a slash and also lookahead to find a slash and 4 digits while matching three word characters.

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Alternative, an even simpler solution, without using regular expressions, given the beginning of the string always contains the same formatted characters is the following

String text = "96.7.4.14 - - [24/Apr/2011:04:20:11 -0400] \"GET /cat.jpg HTTP/1.1\" 200 1243";
int firstLetterOfMonth = text.indexOf('/') + 1;
String month = text.substring(firstLetterOfMonth, firstLetterOfMonth + 3);
System.out.println(month); // Apr