[FIXED] Java regex for matching curly braces and brackets within braces

Issue

I have the following String - There are {num} scores {/game/[game_name]/game_in}. I want to extract num and game_name from the string. I have the following Pattern - "\\{([^}]+)}" which extract num from the String. How can I extend it to extract game_name also?

Solution

In Java, you can use this regex and code:

String s = "{num} scores {/game/[game_name]/game_in}";
Pattern p = Pattern.compile(
                 "\\{([^]\\[\\{\\}]+)\\}.*?\\[([^]\\[\\{\\}]+)]");

List<String> res = p.matcher(s)
   .results()
   .flatMap(mr -> IntStream.rangeClosed(1, mr.groupCount())
   .mapToObj(mr::group))
   .collect(Collectors.toList());
//=> [num, game_name]

RegEx Demo

RegEx Details:

• \{: Match {
• ([^]\[{}]+): Capture group #1 to capture 1+ of any char that is not {, }, [, ]
• }: Match }
• .*?: Match any text (lazy)
• \[: Match [
• ([^]\[{}]+): Capture group #2 to capture 1+ of any char that is not {, }, [, ]
• ]: Match ]

Answered By - anubhava
Answer Checked By - Marie Seifert (JavaFixing Admin)