Java tutorial
/* * Copyright 2002-2016 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; /** * Defines methods for sending messages. * * @author Mark Fisher * @since 4.0 */ @FunctionalInterface public interface MessageChannel { /** * Constant for sending a message without a prescribed timeout. */ long INDEFINITE_TIMEOUT = -1; /** * Send a {@link Message} to this channel. If the message is sent successfully, * the method returns {@code true}. If the message cannot be sent due to a * non-fatal reason, the method returns {@code false}. The method may also * throw a RuntimeException in case of non-recoverable errors. * <p>This method may block indefinitely, depending on the implementation. * To provide a maximum wait time, use {@link #send(Message, long)}. * @param message the message to send * @return whether or not the message was sent */ default boolean send(Message<?> message) { return send(message, INDEFINITE_TIMEOUT); } /** * Send a message, blocking until either the message is accepted or the * specified timeout period elapses. * @param message the message to send * @param timeout the timeout in milliseconds or {@link #INDEFINITE_TIMEOUT} * @return {@code true} if the message is sent, {@code false} if not * including a timeout of an interrupt of the send */ boolean send(Message<?> message, long timeout); }