1 /***************************************************************** 2 * Licensed to the Apache Software Foundation (ASF) under one * 3 * or more contributor license agreements. See the NOTICE file * 4 * distributed with this work for additional information * 5 * regarding copyright ownership. The ASF licenses this file * 6 * to you under the Apache License, Version 2.0 (the * 7 * "License"); you may not use this file except in compliance * 8 * with the License. You may obtain a copy of the License at * 9 * * 10 * http://www.apache.org/licenses/LICENSE-2.0 * 11 * * 12 * Unless required by applicable law or agreed to in writing, * 13 * software distributed under the License is distributed on an * 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * 15 * KIND, either express or implied. See the License for the * 16 * specific language governing permissions and limitations * 17 * under the License. * 18 ****************************************************************/ 19 20 package org.apache.james.util.watchdog; 21 22 /*** 23 * This interface represents an abstract watchdog process that serves to 24 * monitor a situation and triggers an action under an implementation-specific 25 * trigger condition. 26 * 27 */ 28 public interface Watchdog { 29 30 /*** 31 * Start this Watchdog, causing it to begin monitoring. The Watchdog can 32 * be stopped and restarted. 33 */ 34 void start(); 35 36 /*** 37 * Reset this Watchdog. Resets any conditions in the implementations 38 * (time to expiration, etc.) to their original values 39 */ 40 void reset(); 41 42 /*** 43 * Stop this Watchdog, terminating the monitoring condition. The monitor 44 * can be restarted with a call to startWatchdog. 45 */ 46 void stop(); 47 }