Question

I have input stream with the following data:

---------------------------------------------
manil@manil-ubvm:~$ db2level
DB21085I  Instance "manil" uses "64" bits and DB2 code release "SQL10010" with 
level identifier "0201010E".
Informational tokens are "DB2 v10.1.0.0", "s120403", "LINUXAMD64101", and Fix 
Pack "0".
Product is installed at "/home/manil/sqllib".
---------------------------------------------

From above i need v10.1.0.0 to be stored in a string variable.

How to do that using java regular expression?

Answer 1

Use something like this to capture the version pattern :

import java.util.regex.*;

    public class RTest {

            public static void main(String [] args) {
                    String raw_data = "asdkgjasdbf984 sdkjfashfiu 4qwsadkfjnv w98sa-asdf08gywbfsd v1231.123.12.11.1 fkjsdfn9823isd";
                    Pattern version_find = Pattern.compile("v[\\d+\\.?]+");
                    Pattern directory_find = Pattern.compile("[\\/[^\\/]+]+");
                    Matcher version_finder = version_find.matcher(raw_data);
                    while(version_finder.find()) {
                          System.out.println(version_finder.group());
                    }
            }
    }

Output is :

v1231.123.12.11.1
/isd/asdasd2903 ajshdaq09r34/adsj 38/

You really need to understand regexes deeply if you are a programmer. They are one of the essentials. They are hard at first, but once you ‘crack them’ you don’t forget it. Like riding a bike.