+ * Checks whether the client is already connected and throws an exception if
+ * it is not.
+ *
+ * @throws HighLevelException
+ * if the client is not connected
+ */
+ private void checkConnection() throws HighLevelException {
+ synchronized (this) {
+ if (fcpConnection == null) {
+ throw new HighLevelException("client is not connected");
+ }
+ }
+ }
+
+ /**