1 /*
2 * Copyright 2002-2013 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.messaging;
18
19 /**
20 * Defines methods for sending messages.
21 *
22 * @author Mark Fisher
23 * @since 4.0
24 */
25 public interface MessageChannel {
26
27 /**
28 * Constant for sending a message without a prescribed timeout.
29 */
30 public static final long INDEFINITE_TIMEOUT = -1;
31
32
33 /**
34 * Send a {@link Message} to this channel. If the message is sent successfully,
35 * the method returns {@code true}. If the message cannot be sent due to a
36 * non-fatal reason, the method returns {@code false}. The method may also
37 * throw a RuntimeException in case of non-recoverable errors.
38 * <p>This method may block indefinitely, depending on the implementation.
39 * To provide a maximum wait time, use {@link #send(Message, long)}.
40 * @param message the message to send
41 * @return whether or not the message was sent
42 */
43 boolean send(Message<?> message);
44
45 /**
46 * Send a message, blocking until either the message is accepted or the
47 * specified timeout period elapses.
48 * @param message the message to send
49 * @param timeout the timeout in milliseconds or {@link #INDEFINITE_TIMEOUT}
50 * @return {@code true} if the message is sent, {@code false} if not
51 * including a timeout of an interrupt of the send
52 */
53 boolean send(Message<?> message, long timeout);
54
55 }