String s1 = playerName;
for(int p = 0; p < s1.length(); p++){
TS = s1.substring(p,p+1);
if(GetvalidChar(TS))
Disconnect = true;
}
add that at loggin
Public void getvalidchar(String X)
{
for(int p = 0; p < validchars.length(); p++){
if(X == validchars[p])
return true;
}
return false;
}
public String validchars[] = {"a","b"};
Simple typed from my head basic system you can edit to anything you want
EDIT: you can also put invalid chars there