2 * ============LICENSE_START=======================================================
4 * ================================================================================
5 * Copyright (C) 2017 AT&T Intellectual Property. All rights
7 * ================================================================================
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
12 * http://www.apache.org/licenses/LICENSE-2.0
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 * ============LICENSE_END=========================================================
22 package org.openecomp.appc.listener;
25 * This interface defines a listener that subscribes to a DMaaP topic and continually polls for messages. The
26 * listener does all operations in the run() method and long running operations should be created in a separate worker
30 public interface Listener extends Runnable {
33 * Should start a continuous poll to get messages from the message bus only ending when stop() or stopNow() are
36 * @see java.lang.Runnable#run()
42 * Signals the listener to stop accepting new messages to the queue and to cleanly finish processing all remaining
43 * messages in the queue. This can take a significant amount of time to complete depending on the thread pool
44 * characteristics. Similar to {@link #stopNow()}
49 * Signals the listener to stop accepting new messages to the queue and to destroy all remaining messages in the
50 * queue. This will complete quicker than {@link #stop()} at the cost of discarded requests. Recovery of these
51 * requests would have to be caught downstream. Similar to {@link #stop()}
53 public void stopNow();
56 * @return A string that shows various benchmarking data. Can be used by humans to tune the thread pool.
58 public String getBenchmark();
61 * @return The listener's id when requesting messages from DMaaP. Also known as the group id.
63 public String getListenerId();
66 * Sets the listener's id to use when requesting messages from DMaaP. Also known as the group id.
71 public void setListenerId(String idString);