java - split string using regular expression

Question

I need to split a string where there\'s a comma, but it depends where the comma is placed.

As an example

consider the following:

C=75,user_is         


        

Answer 1

consider using a parser generator for parsing this kind of query. E.g: javacc or antlr

Answer 2

As an alternative, if you need more than one level of parentheses, you can create a little string parser for parsing the string character by character.

Answer 3

If you don't have more than one level of parentheses, you could do a split on a comma that isn't followed by a closing ) before an opening (:

String[] splitArray = subjectString.split(
    "(?x),   # Verbose regex: Match a comma\n" +
    "(?!     # unless it's followed by...\n" +
    " [^(]*  # any number of characters except (\n" +
    " \\)    # and a )\n" +
    ")       # end of lookahead assertion");

Your proposed rule would translate as

String[] splitArray = subjectString.split(
    "(?x),        # Verbose regex: Match a comma\n" +
    "(?<!\\p{Lu}) # unless it's preceded by an uppercase letter\n" +
    "(?!\\p{Lu})  # or followed by an uppercase letter");

but then you would miss a split in a text like

Org=NASA,Craft=Shuttle