Display email address as a tooltip

Question

I have seen email services display the email id as e*****[e-mail] on the recovery page.

So, I'm trying to replace [e-mail] e*****[e-mail].

Is it possible to achieve this using String#replace(String)separately? or should I use some REGEX to achieve it.

Thank you for your valuable suggestions at adavance

Answer 1

Search for regex:

\b(\w)\S*?(\S)(?=@)(\S+)\b

Spare Template:

$1****$2$3****$4

RegEx Demo

The code:

String email = "[e-mail]"; 
String repl = email.replaceFirst("\\b(\\w)\\S*?(\\S@)(\\S)\\S*(\\S\\.\\S*)\\b", 
      "$1****$2$3****$4");
//=> a****e@g****l.com

Answer 2

This is possible with the replaceAll function.

(?<!^).(?=.*?.@)

*

DEMO

String s = "[e-mail]";
System.out.println(s.replaceAll("(?<!^).(?=.*?.@)", "*"));

:

e*****[e-mail]

Update:

, e*****e@g***l.com

String s = "[e-mail]";
System.out.println(s.replaceAll("\\B.\\B(?=.*?\\.)", "*"));

:

e*****e@g***l.com

Answer 3

You can also try without regex

 String email = "[e-mail]";
 int start = 1;
 int end = email.indexOf("@") - 1;
 StringBuilder sb = new StringBuilder(email);
 StringBuilder sb1=new StringBuilder();
 for(int i=start;i<end;i++){
    sb1.append("*");
 }
 sb.replace(start, end, sb1.toString());
 System.out.println(sb.toString());

Conclusion:

 e*****[e-mail]

Answer 4

I suggest using indexOfand substring. With a replacement, you may encounter a handset with electronic messages, for [e-mail]