Question

I want to know regular expression will be most effective to achieve the following:

In a date and time stamp string, I want to remove the time stamp if it is just zeros. But the problem is the time stamp can have multiple formats. For example:

2013-02-04 00:00:00
2013-02-04 00:00:00.0
2013-02-04 00:00 AM
2013-02-04 00:00 PM

Thanks

Answer 1

For each line:

line.replaceAll("(00:?)+(.0)?\s*([AP]M)", "");

(              // start time group
00             // strange timestamp symbol
:?             // allow ':'
)+             // strange group can be repeated more than one time
(.0)?          // if ms was specified
\s*            // allow spaces before AM,PM
(              // AM, PM group
[AP]           // A or P letter
M              // M
)?             // AP, PM group can not exists