Answer by TheLostMind for masking of email address in java

Your Look-ahead is kind of complicated. Try this code :

public static void main(String... args) throws Exception {    String s = "nileshkemse@gmail.com";    s= s.replaceAll("(?<=.{3}).(?=.*@)", "*");    System.out.println(s);}

O/P :

nil********@gmail.com