Handling delimiter with escape characters in Java String.split() method

Question

I have searched the web for my query, but didn\'t get the answer which fits my requirement exactly. I have my string like below:

Answer 1

You can use Pattern.quote():

String regex = "(?<!\\\\)" + Pattern.quote(delim);

---

Using your example:

String delim = "|";
String regex = "(?<!\\\\)" + Pattern.quote(delim);

for (String s : "A|B|C|The Steading\\|Keir Allan\\|Braco|E".split(regex))
    System.out.println(s);

A
B
C
The Steading\|Keir Allan\|Braco
E

---

You can extend this to use a custom escape sequence as well:

String delim = "|";
String esc = "+";
String regex = "(?<!" + Pattern.quote(esc) + ")" + Pattern.quote(delim);

for (String s : "A|B|C|The Steading+|Keir Allan+|Braco|E".split(regex))
    System.out.println(s);

A
B
C
The Steading+|Keir Allan+|Braco
E

Answer 2

I know this is an old thread, but the lookbehind solution has an issue, that it doesn't allow escaping of the escape character (the split would not occur on A|B|C|The Steading\\|Keir Allan\|Braco|E)).

The positive matching solution in thread Regex and escaped and unescaped delimiter works better (with modification using Pattern.quote() if the delimiter is dynamic).