Java-使用正则表达式捕获可选字段？

Question

I've a regex that correctly captures values from the result of a string.

regex is look like;

intGetHatSaatRenk_v22=anyType{SiraNo=(.*?); HatKodu=(.*?) ; GunTipi=(.*?); Gidis=(.*?); ? }; 

But the problem is the source is like;

intGetHatSaatRenk_v22=anyType{SiraNo=54; HatKodu=502 ; GunTipi=C; Gidis=12:00; RenkGidis=0000FF; }; 

intGetHatSaatRenk_v22=anyType{SiraNo=55; HatKodu=502 ; GunTipi=C; Gidis=12:07; }; intGetHatSaatRenk_v22=anyType{SiraNo=56; HatKodu=502 ; GunTipi=C; Gidis=12:14; };

as you can see there is an optional field that named RenkGidis , how can i get the value from RenkGidis if it's not null?

with the regex code that i wrote above, i can get if RenkGidis exists in group(4) like 12:00; RenkGidis=0000FF but group(4) must be only 12:00 .

I hope that I could explain my problem.

Answer 1

Might want to make the last group optional :

intGetHatSaatRenk_v22=anyType\{SiraNo=([^;\s]*);\s+HatKodu=([^;\s]*)\s*;\s+GunTipi=([^;\s]*);\s+Gidis=([^;\s]*);(?:\s+RenkGidis=([^;\s]*);)?

As a Java string:

"intGetHatSaatRenk_v22=anyType\\{SiraNo=([^;\\s]*);\\s+HatKodu=([^;\\s]*)\\s*;\\s+GunTipi=([^;\\s]*);\\s+Gidis=([^;\\s]*);(?:\\s+RenkGidis=([^;\\s]*);)?"

At the last group ( ?: prevents the group to be captured into output. ( inside ) catpured as usual.

Also changed .*? to [^;\\s]* (negation of [;\\s] -> any characters, that are no white-space or ; )

---

As Alan mentioned in the comments, for not getting a null match for the optional part, eg just make RenkGidis optional and wrap the value in an alternation with nothing: ([^;\\s]*;|)

intGetHatSaatRenk_v22=anyType\{SiraNo=([^;\s]*);\s+HatKodu=([^;\s]*)\s*;\s+GunTipi=([^;\s]*);\s+Gidis=([^;\s]*);(?:\s+RenkGidis=)?([^;\s]*|)

As a Java string:

"intGetHatSaatRenk_v22=anyType\\{SiraNo=([^;\\s]*);\\s+HatKodu=([^;\\s]*)\\s*;\\s+GunTipi=([^;\\s]*);\\s+Gidis=([^;\\s]*);(?:\\s+RenkGidis=)?([^;\\s]*|)"

Answer 2

The regex could look like this

intGetHatSaatRenk_v22=anyType\{SiraNo=(.*?); HatKodu=(.*?) ; GunTipi=(.*?); Gidis=(.*?);( RenkGidis=.*?;\s*|\s*)\};

Group 5 will then be either " RenkGidis=0000FF;" or " ". You can then use a second regex to get 0000FF.