正则表达式如何写？

Question

我想把以下这段字符串中，格式如"aaa.bbb.ccc.ddd"整个串替换成单个字符"2"，用string.replaceAll(regx,replacement)方法去实现，但是"aaa.bbb.ccc.ddd"的正则表达式如何写？
(((RRCAttempt.Mo.ConvCall + RRCAttempt.Mo.StrmCall +
RRCAttempt.Mo.IntactCall + RRCAttempt.Mo.BgrdCall +
RRCAttempt.Mo.SubsTrafCall + RRCAttempt.EmrCall +
RRCAttempt.Mo.HighPSig + RRCAttempt.Mo.LowPSig +
RRCAttempt.Mo.Presv) - Fail.RRC.State1NorMo) *
(Call.Answer.Mo.Cs.ConvVce + Call.Answer.Mo.Cs.ConvCirEtc +
Call.Answer.Mo.Cs.Emr + Call.Answer.Mo.Cs.SMS +
Call.Answer.Mo.Cs.Suppl)) / ((RRCAttempt.Mo.ConvCall +
RRCAttempt.Mo.StrmCall + RRCAttempt.Mo.IntactCall +
RRCAttempt.Mo.BgrdCall + RRCAttempt.Mo.SubsTrafCall +
RRCAttempt.EmrCall + RRCAttempt.Mo.HighPSig +
RRCAttempt.Mo.LowPSig + RRCAttempt.Mo.Presv) *
(Call.AttEstab.Mo.Cs.Conv + Call.AttEstab.Mo.Cs.Emr +
Call.AttEstab.Mo.Cs.SMS + Call.AttEstab.Mo.Cs.Suppl))
转换成：
(((2 + 2 +
2 + ........略

Answer 1

[code="java"]
public static String rr(String input, String replace) {
return input.replaceAll("[a-zA-Z]+(\.[a-zA-Z]+)*", replace);
}
[/code]