    001    // Copyright 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.ioc.services.cron;
    016
    017    /**
    018     * A service that executes a job at intervals specified by a {@link Schedule}.
    019     *
    020     * @since 5.3
    021     */
    022    public interface PeriodicExecutor
    023    {
    024        /**
    025         * Adds a job to be executed. The job is executed in a thread pool (via {@link org.apache.tapestry5.ioc.services.ParallelExecutor#invoke(org.apache.tapestry5.ioc.Invokable)}), as determined by the schedule.
    026         *
    027         * @param schedule defines when the job will next execute
    028         * @param name     a name used in debugging output related to the job
    029         * @param job      a Runnable object that represents the work to be done
    030         * @return a PeriodicJob that can be used to query when the job executes, or to cancel its execution
    031         */
    032        PeriodicJob addJob(Schedule schedule, String name, Runnable job);
    033    }