Depends on what you name "CSV" if you work with really simple files, split(",")
may work.
If you should handle arbitrary CSV files, you better read http://ostermiller.org/utils/CSV.html and http://www.csvreader.com/java_csv.php (which I personnaly like less) to understand the size of CSV reading problem.
As a little help (if you need it):
Pattern splitter = Pattern.compile(",(?=(?:[^\"]*\"[^\"]*\")*(?![^\"]*\"))");
will handle most of string including strings like "something"",""",""",""another"
, which covers about 2/3 of CSVs.
Result of split: "something"","""
and """,""another"