How to replace all special characters except for underscore and numbers in java?

Question

I want to replace all special characters from the string object BusDetails below with a blank "" except for _(underscore) and numbers in java ?

BusDetails=BusDetails.replaceAll("—", "").replaceAll("\\s+","_").replaceAll("ROUTE", "BUS").replaceAll("-", "_");

Answer 1

BusDetails = BusDetails.replaceAll("[^a-zA-Z0-9_-]", "");

Using the regex pattern "[^a-zA-Z0-9_-]" we can replace all special characters (symbols) from the string except letters, numbers and '_'.