/* package whatever; // don't place package name! */
import java.util.*;
import java.lang.*;
import java.io.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
{
String email
= "any_email@provider.whatever"; String masked
= email.
replaceAll("(?<=^.|@.)(?<toreplace>[^@]*?)(?=.@|.$)",
"***"); }
}
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