org.springframework.web.socket.messaging.SubProtocolErrorHandler Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.socket.messaging;
import org.springframework.lang.Nullable;
import org.springframework.messaging.Message;
/**
* A contract for handling sub-protocol errors sent to clients.
*
* @author Rossen Stoyanchev
* @since 4.2
* @param the message payload type
*/
public interface SubProtocolErrorHandler
{
/**
* Handle errors thrown while processing client messages providing an
* opportunity to prepare the error message or to prevent one from being sent.
*
Note that the STOMP protocol requires a server to close the connection
* after sending an ERROR frame. To prevent an ERROR frame from being sent,
* a handler could return {@code null} and send a notification message
* through the broker instead, e.g. via a user destination.
* @param clientMessage the client message related to the error, possibly
* {@code null} if error occurred while parsing a WebSocket message
* @param ex the cause for the error, never {@code null}
* @return the error message to send to the client, or {@code null} in which
* case no message will be sent.
*/
@Nullable
Message
handleClientMessageProcessingError(@Nullable Message
clientMessage, Throwable ex);
/**
* Handle errors sent from the server side to clients, e.g. errors from the
* {@link org.springframework.messaging.simp.stomp.StompBrokerRelayMessageHandler
* "broke relay"} because connectivity failed or the external broker sent an
* error message, etc.
* @param errorMessage the error message, never {@code null}
* @return the error message to send to the client, or {@code null} in which
* case no message will be sent.
*/
@Nullable
Message
handleErrorMessageToClient(Message
errorMessage);
}