File I/O and StringTokenizer

Question

Hi
This may be really simple, but I seem to have problem here. I am reading a txt file using FileReader and I am just printing it out. The txt file has lots of lines. What I want now is to take just the lines which has an = sign on it( there should be only one =) and print just that. This line in the txt file is the form key=value(a hashtable) I need to printout just those lines which are of these form key=value and ignore all the lines. I know I should use the StringTokenizer, but how do I read the.txt file and check if there is any blank line or illegal line and select the line with key=value and print it.
Please let me know.
Thanks

Answer 1

yourStuff() is a snippet that you will change with your source code.
The regular expression is:
"^\\w+=\\w+$"
It means: "from starting data input position (^) followed with one or more char in set [a-zA-Z0-9_] (\\w+), followed with an '=', followed with one or more char (\\w+) till the end of data input ($)".
It assures no more than one '=' in a line but since you can have blankspaces surrounding this char use that: "^\\w+\\s*=\\s*\\w+$".
The method "matches()" means "exactly matches" and using anchors: ^ and $, ie; exactly matches from start to end of data input.