avinash09 <avinash.i...@gmail.com> wrote: > regex="^(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*), > (.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*),(.*)$"
A better solution seems to have been presented, but for the record I would like to note that the regexp above is quite an effective performance bomb: For each group, the evaluation time roughly doubles. Not a problem for 10 groups, but you have 28. I made a little test and matching a single sample line with 20 groups took 120 ms/match, 24 groups took 2 seconds and 28 groups took 30 seconds on my machine. If you had 50 groups, a single match would take 4 years. The explanation is that Java regexps are greedy: Every one of your groups starts by matching to the end of the line, then a comma is reached in the regexp and it backtracks. The solution is fortunately both simple and applicable to many other regexps: Make your matches terminate as soon as possible. In this case, instead of having groups with (.*), use ([^,]*) instead, which means that each group matches everything, except commas. The combined regexp then looks like this: regex="^([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),...([^,]*)$" The match speed for 28 groups with that regexp was about 0.002ms (average over 1000 matches). - Toke Eskildsen
