Restrição de Login

Credits by Bian from L2jBrasil

### Eclipse Workspace Patch 1.0
#P L2jFrozen_GameServer
Index: head-src/com/l2jfrozen/loginserver/LoginController.java
===================================================================
--- head-src/com/l2jfrozen/loginserver/LoginController.java (revision 1118)
+++ head-src/com/l2jfrozen/loginserver/LoginController.java (working copy)
@@ -32,6 +32,9 @@
 import java.sql.ResultSet;
 import java.util.Collection;
 import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;

 import javax.crypto.Cipher;

@@ -650,6 +653,9 @@
        // LOGGER it anyway
        Log.add("'" + (user == null ? "null" : user) + "' " + (address == null ? "null" : address.getHostAddress()), "logins_ip");

+       if (!isValidLogin(user))
+           return false;
+
        // player disconnected meanwhile
        if (address == null)
            return false;
@@ -972,4 +978,25 @@
            }
        }
    }
+
+   public static boolean isValidLogin(String text)
+   {
+       return isValidPattern(text, "^[A-Za-z0-9]{1,16}$");
+   }
+
+   public static boolean isValidPattern(String text, String regex)
+   {
+       Pattern pattern;
+
+       try
+       {
+           pattern = Pattern.compile(regex);
+       }
+       catch (PatternSyntaxException e)
+       {
+           pattern = Pattern.compile(".*");
+       }
+       Matcher regexp = pattern.matcher(text);
+       return regexp.matches();
+   }
 }