Allow extendo customizo.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@2064 6335cc39-0255-0410-8fd6-9bcaacd3b74c

src/java/com/samskivert/servlet/user/Username.java

@@ -19,26 +19,12 @@ public class Username
     public static final String NAME_REGEX = "^[_A-Za-z0-9]*$";
 
     /**
-     * Creates a username instance. Usernames must consist only of
-     * characters that match the following regular expression:
-     * <code>[_A-Za-z0-9]+</code> and be longer than two characters.
+     * Creates a username instance.
      */
     public Username (String username)
         throws InvalidUsernameException
     {
-	// check length
-	if (username.length() < MINIMUM_USERNAME_LENGTH) {
-	    throw new InvalidUsernameException("error.username_too_short");
-	}
-	if (username.length() > MAXIMUM_USERNAME_LENGTH) {
-	    throw new InvalidUsernameException("error.username_too_long");
-	}
-
-	// check that it's only valid characters
-	if (!username.matches(NAME_REGEX)) {
-	    throw new InvalidUsernameException("error.invalid_username");
-	}
-
+        validateName(username);
         _username = username;
     }
 
@@ -54,5 +40,27 @@ public class Username
         return _username;
     }
 
+    /**
+     * Validates our username. The default implementation requires that usernames consist only of
+     * characters that match the {@link #NAME_REGEX} regular expression and be between {@link
+     * #MINIMUM_USERNAME_LENGTH} and {@link #MAXIMUM_USERNAME_LENGTH} characters.
+     */
+    protected void validateName (String username)
+        throws InvalidUsernameException
+    {
+	// check length
+	if (username.length() < MINIMUM_USERNAME_LENGTH) {
+	    throw new InvalidUsernameException("error.username_too_short");
+	}
+	if (username.length() > MAXIMUM_USERNAME_LENGTH) {
+	    throw new InvalidUsernameException("error.username_too_long");
+	}
+
+	// check that it's only valid characters
+	if (!username.matches(NAME_REGEX)) {
+	    throw new InvalidUsernameException("error.invalid_username");
+	}
+    }
+
     protected String _username;
 }