org.springframework.messaging.SubscribableChannel Maven / Gradle / Ivy
/*
* Copyright 2002-2013 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;
/**
* A {@link MessageChannel} that maintains a registry of subscribers and invokes
* them to handle messages sent through this channel.
*
* @author Mark Fisher
* @since 4.0
*/
public interface SubscribableChannel extends MessageChannel {
/**
* Register a message handler.
* @return {@code true} if the handler was subscribed or {@code false} if it
* was already subscribed.
*/
boolean subscribe(MessageHandler handler);
/**
* Un-register a message handler.
* @return {@code true} if the handler was un-registered, or {@code false}
* if was not registered.
*/
boolean unsubscribe(MessageHandler handler);
}