Handle unknown connectors consistently and quietly as described in #8111 (#8741)

Fixes #8629

1 files changed, 14 insertions, 6 deletions

diff --git a/server/src/main/java/com/vaadin/server/communication/ServerRpcHandler.java b/server/src/main/java/com/vaadin/server/communication/ServerRpcHandler.java
index bee4720273..e4783cbf6e 100644
--- a/server/src/main/java/com/vaadin/server/communication/ServerRpcHandler.java
+++ b/server/src/main/java/com/vaadin/server/communication/ServerRpcHandler.java
@@ -350,11 +350,9 @@ public class ServerRpcHandler implements Serializable {
                 final ClientConnector connector = connectorTracker
                         .getConnector(invocation.getConnectorId());
                 if (connector == null) {
-                    getLogger().log(Level.WARNING,
-                            "Received RPC call for unknown connector with id {0} (tried to invoke {1}.{2})",
-                            new Object[] { invocation.getConnectorId(),
-                                    invocation.getInterfaceName(),
-                                    invocation.getMethodName() });
+                    logUnknownConnector(invocation.getConnectorId(),
+                            invocation.getInterfaceName(),
+                            invocation.getMethodName());
                     continue;
                 }
 
@@ -423,6 +421,13 @@ public class ServerRpcHandler implements Serializable {
         }
     }
 
+    private void logUnknownConnector(String connectorId, String interfaceName,
+            String methodName) {
+        getLogger().log(Level.FINE,
+                "Received RPC call for unknown connector with id {0} (tried to invoke {1}.{2})",
+                new Object[] { connectorId, interfaceName, methodName });
+    }
+
     /**
      * Handles the given RPC method invocation for the given connector
      *
@@ -575,7 +580,10 @@ public class ServerRpcHandler implements Serializable {
             JsonArray parametersJson, ConnectorTracker connectorTracker)
             throws JsonException {
         ClientConnector connector = connectorTracker.getConnector(connectorId);
-
+        if (connector == null) {
+            logUnknownConnector(connectorId, interfaceName, methodName);
+            return null;
+        }
         ServerRpcManager<?> rpcManager = connector.getRpcManager(interfaceName);
         if (rpcManager == null) {
             /*