My regex is
(?:--|#|\/\*|{)
When i compile this using Pattern.complie() in java, I am getting *Illegal Repetitive Character *
I tested this regex
(a|\/\*|b)
When i compiled this, It shows no error.
Why does this occur ?
Gábor Bakos
It is because of {. It is used to specify how many times something should it be repeated. For instance x{2,4} will match x repeated 2 (xx), 3 (xxx) or 4 (xxxx) times.
If you want regex to match { literal it needs to be escaped:
(?:--|#|\/\*|\{)
来源：https://stackoverflow.com/questions/22146173/java-regex-ilegal-repetition-character