org.springframework.integration.store.MessageGroup.java Source code

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Here is the source code for org.springframework.integration.store.MessageGroup.java

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/*
 * Copyright 2002-2019 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.integration.store;

import java.util.Collection;

import org.springframework.messaging.Message;

/**
 * A group of messages that are correlated with each other and should be processed in the same context.
 * <p>
 * The message group allows implementations to be mutable, but this behavior is optional. Implementations should take
 * care to document their thread safety and mutability.
 *
 * @author Dave Syer
 * @author Oleg Zhurakousky
 * @author Gary Russell
 * @author Artem Bilan
 */
public interface MessageGroup {

    /**
     * Query if the message can be added.
     *
     * @param message The message.
     * @return true if the message can be added.
     */
    boolean canAdd(Message<?> message);

    /**
     * Add the message to this group.
     * @param messageToAdd the message to add.
     * @since 4.3
     */
    void add(Message<?> messageToAdd);

    /**
     * Remove the message from this group.
     * @param messageToRemove the message to remove.
     * @return {@code true} if a message was removed.
     * @since 4.3
     */
    boolean remove(Message<?> messageToRemove);

    /**
     * Returns all available Messages from the group at the time of invocation
     *
     * @return The messages.
     */
    Collection<Message<?>> getMessages();

    /**
     * @return the key that links these messages together
     */
    Object getGroupId();

    /**
     * @return the sequenceNumber of the last released message. Used in Resequencer use cases only
     */
    int getLastReleasedMessageSequenceNumber();

    void setLastReleasedMessageSequenceNumber(int sequenceNumber);

    /**
     * @return true if the group is complete (i.e. no more messages are expected to be added)
     */
    boolean isComplete();

    /**
     * Complete the group.
     */
    void complete();

    /**
     * @return the size of the sequence expected 0 if unknown
     */
    int getSequenceSize();

    /**
     * @return the total number of messages in this group
     */
    int size();

    /**
     * @return a single message from the group
     */
    Message<?> getOne();

    /**
     * @return the timestamp (milliseconds since epoch) associated with the creation of this group
     */
    long getTimestamp();

    /**
     * @return the timestamp (milliseconds since epoch) associated with the time this group was last updated
     */
    long getLastModified();

    void setLastModified(long lastModified);

    void clear();

}