001/*
002 * Copyright 2002-2017 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.socket.messaging;
018
019import org.springframework.lang.Nullable;
020import org.springframework.messaging.Message;
021import org.springframework.messaging.simp.stomp.StompCommand;
022import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
023import org.springframework.messaging.support.MessageBuilder;
024import org.springframework.messaging.support.MessageHeaderAccessor;
025import org.springframework.util.Assert;
026
027/**
028 * A {@link SubProtocolErrorHandler} for use with STOMP.
029 *
030 * @author Rossen Stoyanchev
031 * @since 4.2
032 */
033public class StompSubProtocolErrorHandler implements SubProtocolErrorHandler<byte[]> {
034
035        private static final byte[] EMPTY_PAYLOAD = new byte[0];
036
037
038        @Override
039        @Nullable
040        public Message<byte[]> handleClientMessageProcessingError(@Nullable Message<byte[]> clientMessage, Throwable ex) {
041                StompHeaderAccessor accessor = StompHeaderAccessor.create(StompCommand.ERROR);
042                accessor.setMessage(ex.getMessage());
043                accessor.setLeaveMutable(true);
044
045                StompHeaderAccessor clientHeaderAccessor = null;
046                if (clientMessage != null) {
047                        clientHeaderAccessor = MessageHeaderAccessor.getAccessor(clientMessage, StompHeaderAccessor.class);
048                        if (clientHeaderAccessor != null) {
049                                String receiptId = clientHeaderAccessor.getReceipt();
050                                if (receiptId != null) {
051                                        accessor.setReceiptId(receiptId);
052                                }
053                        }
054                }
055
056                return handleInternal(accessor, EMPTY_PAYLOAD, ex, clientHeaderAccessor);
057        }
058
059        @Override
060        @Nullable
061        public Message<byte[]> handleErrorMessageToClient(Message<byte[]> errorMessage) {
062                StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(errorMessage, StompHeaderAccessor.class);
063                Assert.notNull(accessor, "No StompHeaderAccessor");
064                if (!accessor.isMutable()) {
065                        accessor = StompHeaderAccessor.wrap(errorMessage);
066                }
067                return handleInternal(accessor, errorMessage.getPayload(), null, null);
068        }
069
070        protected Message<byte[]> handleInternal(StompHeaderAccessor errorHeaderAccessor, byte[] errorPayload,
071                        @Nullable Throwable cause, @Nullable StompHeaderAccessor clientHeaderAccessor) {
072
073                return MessageBuilder.createMessage(errorPayload, errorHeaderAccessor.getMessageHeaders());
074        }
075
076}