使用正则表达式进行Java解析Wiki语法

Question

I'm making an application to generate HTML document from wiki markup . And I figured regex was the right way to replace markup to HTML tags. I came up with a working regex to find markup, but I couldn't find Java API to replace it while retaining the sentence.

The regex suggested by an answer:
--([^-]+)-- (regex --([^-])+-- doesn't behave well with Java API. Moving + inside the capturing group solves the problem.)

Example:
--This is strike-- should be <strike>This is strike</strike>
But cases like This is ---- normal text or ---Triple hyphens--- should NOT be replaced. However, cases like --striked----also striked-- works.

Only Java 6 please.
Any help is welcome. Thanks in advance.

EDIT: Based on an answer, it seems I can use $1 for this purpose.

Answer 1

Groups (...) are numbered from 1 in order of occurrence. Postfix operator * = 0 or more, + is 1 or more.

s = s.replaceAll("--([^-]+)--", "<strike>$1</strike>");

Answer 2

After asking one of my friend, I got an answer.

--([^-]+(-[^-]+)*)-- Will work correctly and capture subject string as $1