Java split and replace

Question

I have the following string

String path = "(tags:homepage).(tags:project mindshare).(tags:5.5.x).(tags:project 5.x)";

I used following code,

String delims = "\\.";

String[] tokens = path.split(delims);
int tokenCount = tokens.length;
for (int j = 0; j < tokenCount; j++) {
    System.out.println("Split Output: "+ tokens[j]);
}

Current output is

Split Output: (tags:homepage)
Split Output: (tags:project mindshare)
Split Output: (tags:5
Split Output: 5
Split Output: x)
Split Output: (tags:project 5
Split Output: x)

End goal is to convert this string into

String newpath = "(tags:homepage)(tags:project mindshare)(tags:5.5.x)(tags:project 5.x)";

Then use 'System.out.print' and not 'println' if you don't want newlines. — AlBlue, Aug 08 '16 at 09:18
@MuratK. - Its not that simple. He will need to replace only those `.` which are preceeded by a `(` — TheLostMind, Aug 08 '16 at 09:19
Possible duplicate of [Regex to match only commas not in parentheses?](http://stackoverflow.com/questions/9030036/regex-to-match-only-commas-not-in-parentheses) — Tom, Aug 08 '16 at 09:19
yeah, I'm aware of replaceAll, thought thats bad way of programming. Want to use some tokenization @MuratK. — srinisunka, Aug 08 '16 at 09:23
@TheLostMind Yeah, I edited it and provided a replaceAll answer. — Murat Karagöz, Aug 08 '16 at 09:24

TheLostMind · Accepted Answer · 2016-08-08T11:04:23.140

3

You can use a positive lookbehind to achieve this :

String path = "(tags:homepage).(tags:project mindshare).(tags:5.5.x).(tags:project 5.x)";
String newPath = path.replaceAll("(?<=\\))\\.", ""); // look for periods preceeded by `)`
System.out.println(newPath);

O/P :

(tags:homepage)(tags:project mindshare)(tags:5.5.x)(tags:project 5.x)

edited Aug 08 '16 at 11:04

answered Aug 08 '16 at 09:19

TheLostMind

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Any other better way of doing it, other then replaceAll ? – srinisunka Aug 08 '16 at 09:26
@srinisunka - Yes, there are, split and append for example.. Or even indexOf + subString etc in a loop. But none as elegant as `replaceAll` – TheLostMind Aug 08 '16 at 09:27
Then use `split()` using the same regex. Then you will get individual tokens which can then be changed @srinisunka – TheLostMind Aug 08 '16 at 09:30
@srinisunka - If you want a solution without using regex, then check Tunaki's answer. – TheLostMind Aug 08 '16 at 09:41

score 3 · Answer 2 · answered Aug 08 '16 at 09:33

You can do this without using a regular expression, in a clean and simple way, that even supports nested parentheses (for the day you'll need to support them).

What you want to do here is to keep everything that is inside parentheses, so we can just loop over the characters and keep a count of open parentheses. If this count is greater than 0, we add the character (it means we're inside parens); if not, we disregard the character.

String path = "(tags:homepage).(tags:project mindshare).(tags:5.5.x).(tags:project 5.x)";

StringBuilder sb = new StringBuilder();
int openParens = 0;
for (char c : path.toCharArray()) {
    if (c == '(') openParens++;
    if (openParens > 0) sb.append(c);
    if (c == ')') openParens--;
}

System.out.println(sb.toString());

This has the advantage that you don't implicly rely on: having a single dot between parens, not having nested parens, etc.

score 0 · Answer 3 · answered Aug 08 '16 at 09:22

0

Here is a simple approach.

System.out.println("(tags:homepage).(tags:project mindshare).(tags:5.5.x).(tags:project 5.x)".replaceAll("\\)\\.\\(", ")("));

output is

(tags:homepage)(tags:project mindshare)(tags:5.5.x)(tags:project 5.x)

answered Aug 08 '16 at 09:22

Murat Karagöz

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Java split and replace

3 Answers3