Question

I’m having a little trouble constructing the regular expression using java.

The constraint is, I need to split a string seperated by !. The two strings will be enclosed in double quotes.
For example:

"value"!"value"

If I performed a java split() on the string above, I want to get:

value
value

However the catch is value can be any characters/punctuations/numerical character/spaces/etc..

So here’s a more concrete example. Input:

""he! "l0"!"wor!"d1"

Java’s split() should return:

"he! "l0
wor!"d1

Any help is much appreciated. Thanks!

Answer 1

Try this expression: (".*")\s*!\s*(".*")

Although it would not work with split, it should work with Pattern and Matcher and return the 2 strings as groups.

String input = "\"  \"he\"\"\"\"! \"l0\" ! \"wor!\"d1\"";
Pattern p = Pattern.compile("(\".*\")\\s*!\\s*(\".*\")");
Matcher m = p.matcher(input);
if(m.matches())
{
  String s1 = m.group(1); //"  "he""""! "l0"
  String s2 = m.group(2); //"wor!"d1"
}

Edit:

This would not work for all cases, e.g. "he"!"llo" ! "w" ! "orld" would get the wrong groups. In that case it would be really hard to determine which ! should be the separator. That’s why often rarely used characters are used to separate parts of a string, like @ in email addresses 🙂