Get all captured groups in Java

Question

I want to match a single word inside brackets(including the brackets), my Regex below is working but it's not returning me all groups.

Here's my code:

String text = "This_is_a_[sample]_text[notworking]";
Matcher matcher = Pattern.compile("\\[([a-zA-Z_]+)\\]").matcher(text);                                     
if (matcher.find()) {
    for (int i = 0; i <= matcher.groupCount(); i++) {
    System.out.println("------------------------------------");
    System.out.println("Group " + i + ": " + matcher.group(i));
}

Also I've tested it in Regex Planet and it seems to work.

It must return 4 groups:

------------------------------------
Group 0: [sample]
------------------------------------
Group 1: sample
------------------------------------
Group 2: [notworking]
------------------------------------
Group 3: notworking

But it's returning just it:

------------------------------------
Group 0: [sample]
------------------------------------
Group 1: sample

What's wrong?

Answer 1

JAVA does not offer fancy global option to find all the matches at once. So, you need while loop here

int i = 0;
while (matcher.find()) {
   for (int j = 0; j <= matcher.groupCount(); j++) {
      System.out.println("------------------------------------");
      System.out.println("Group " + i + ": " + matcher.group(j));
      i++;
   }
}

Ideone Demo