Java tutorial
/* * 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; import org.springframework.lang.Nullable; /** * A {@link MessageChannel} from which messages may be actively received through polling. * * @author Mark Fisher * @since 4.0 */ public interface PollableChannel extends MessageChannel { /** * Receive a message from this channel, blocking indefinitely if necessary. * @return the next available {@link Message} or {@code null} if interrupted */ @Nullable Message<?> receive(); /** * Receive a message from this channel, blocking until either a message is available * or the specified timeout period elapses. * @param timeout the timeout in milliseconds or {@link MessageChannel#INDEFINITE_TIMEOUT}. * @return the next available {@link Message} or {@code null} if the specified timeout * period elapses or the message reception is interrupted */ @Nullable Message<?> receive(long timeout); }