org.springframework.messaging.simp.broker.AbstractSubscriptionRegistry.java Source code

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Here is the source code for org.springframework.messaging.simp.broker.AbstractSubscriptionRegistry.java

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/*
 * 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.messaging.simp.broker;

import org.apache.commons.logging.Log;

import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.simp.SimpLogging;
import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
import org.springframework.messaging.simp.SimpMessageType;
import org.springframework.util.CollectionUtils;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;

/**
 * Abstract base class for implementations of {@link SubscriptionRegistry} that
 * looks up information in messages but delegates to abstract methods for the
 * actual storage and retrieval.
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public abstract class AbstractSubscriptionRegistry implements SubscriptionRegistry {

    private static final MultiValueMap<String, String> EMPTY_MAP = CollectionUtils
            .unmodifiableMultiValueMap(new LinkedMultiValueMap<>());

    protected final Log logger = SimpLogging.forLogName(getClass());

    @Override
    public final void registerSubscription(Message<?> message) {
        MessageHeaders headers = message.getHeaders();

        SimpMessageType messageType = SimpMessageHeaderAccessor.getMessageType(headers);
        if (!SimpMessageType.SUBSCRIBE.equals(messageType)) {
            throw new IllegalArgumentException("Expected SUBSCRIBE: " + message);
        }

        String sessionId = SimpMessageHeaderAccessor.getSessionId(headers);
        if (sessionId == null) {
            if (logger.isErrorEnabled()) {
                logger.error("No sessionId in  " + message);
            }
            return;
        }

        String subscriptionId = SimpMessageHeaderAccessor.getSubscriptionId(headers);
        if (subscriptionId == null) {
            if (logger.isErrorEnabled()) {
                logger.error("No subscriptionId in " + message);
            }
            return;
        }

        String destination = SimpMessageHeaderAccessor.getDestination(headers);
        if (destination == null) {
            if (logger.isErrorEnabled()) {
                logger.error("No destination in " + message);
            }
            return;
        }

        addSubscriptionInternal(sessionId, subscriptionId, destination, message);
    }

    @Override
    public final void unregisterSubscription(Message<?> message) {
        MessageHeaders headers = message.getHeaders();

        SimpMessageType messageType = SimpMessageHeaderAccessor.getMessageType(headers);
        if (!SimpMessageType.UNSUBSCRIBE.equals(messageType)) {
            throw new IllegalArgumentException("Expected UNSUBSCRIBE: " + message);
        }

        String sessionId = SimpMessageHeaderAccessor.getSessionId(headers);
        if (sessionId == null) {
            if (logger.isErrorEnabled()) {
                logger.error("No sessionId in " + message);
            }
            return;
        }

        String subscriptionId = SimpMessageHeaderAccessor.getSubscriptionId(headers);
        if (subscriptionId == null) {
            if (logger.isErrorEnabled()) {
                logger.error("No subscriptionId " + message);
            }
            return;
        }

        removeSubscriptionInternal(sessionId, subscriptionId, message);
    }

    @Override
    public final MultiValueMap<String, String> findSubscriptions(Message<?> message) {
        MessageHeaders headers = message.getHeaders();

        SimpMessageType type = SimpMessageHeaderAccessor.getMessageType(headers);
        if (!SimpMessageType.MESSAGE.equals(type)) {
            throw new IllegalArgumentException("Unexpected message type: " + type);
        }

        String destination = SimpMessageHeaderAccessor.getDestination(headers);
        if (destination == null) {
            if (logger.isErrorEnabled()) {
                logger.error("No destination in " + message);
            }
            return EMPTY_MAP;
        }

        return findSubscriptionsInternal(destination, message);
    }

    protected abstract void addSubscriptionInternal(String sessionId, String subscriptionId, String destination,
            Message<?> message);

    protected abstract void removeSubscriptionInternal(String sessionId, String subscriptionId, Message<?> message);

    protected abstract MultiValueMap<String, String> findSubscriptionsInternal(String destination,
            Message<?> message);

}