java - 具有可变组数的正则表达式？

Question

是否可以创建具有可变数量组的正则表达式？

例如运行后...

Pattern p = Pattern.compile("ab([cd])*ef");
Matcher m = p.matcher("abcddcef");
m.matches();

...我想要类似的东西

• m.group(1) = "c"
• m.group(2) = "d"
• m.group(3) = "d"
• m.group(4) = "c".

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(背景:我正在解析一些数据行，其中一个“字段”正在重复。我想避免这些字段的 matcher.find 循环。)

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正如@Tim Pietzcker 在评论中指出的那样，perl6和 .NET有这个功能。

Answer 1

根据documentation , Java 正则表达式不能这样做:

The captured input associated with a group is always the subsequence that the group most recently matched. If a group is evaluated a second time because of quantification then its previously-captured value, if any, will be retained if the second evaluation fails. Matching the string "aba" against the expression (a(b)?)+, for example, leaves group two set to "b". All captured input is discarded at the beginning of each match.

(强调)