ru.retbansk.utils.scheduled.DynamicSchedule.java Source code

Introduction

Here is the source code for ru.retbansk.utils.scheduled.DynamicSchedule.java

Source

/*
 * Copyright 2012 the original author.
 *
 * 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
 *
 *      http://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 ru.retbansk.utils.scheduled;

import java.util.Date;
import java.util.concurrent.ScheduledFuture;

import org.apache.log4j.Logger;
import org.springframework.scheduling.TaskScheduler;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;

/**
 * Name tells everything. Its dynamic schedule. It is used to provide runtime configuration of the schedule. 
 * Main method is <code>setDelay(int delay)</code>. It automatically restarts schedule if the new delay is less than the old one. Or waits the next schedule if the new delay is greater 
 * @author Siarhei Yanusheuski
 * @since 25.10.2012
 */
public class DynamicSchedule implements Trigger {
    protected static Logger logger = Logger.getLogger("service");
    private TaskScheduler scheduler;
    private Runnable task;
    private int delay;
    private ScheduledFuture<?> scheduledFuture;

    /**
     * Immediately restarts schedule at initializing
     * @param scheduler
     * @param task
     * @param delay Milliseconds (1000 = 1 second)
     */
    public DynamicSchedule(TaskScheduler scheduler, Runnable task, int delay) {
        this.scheduler = scheduler;
        this.task = task;
        reset(delay);
    }

    /**
     * Returns pretty output of milliseconds
     * @param milisec Milliseconds (1000 = 1 second)
     * @return pretty String with the view like 00:00:00
     */
    public String getElapsedTimeHoursMinutesSecondsString(int milisec) {
        int time = milisec / 1000;
        String seconds = Integer.toString((int) (time % 60));
        String minutes = Integer.toString((int) ((time % 3600) / 60));
        String hours = Integer.toString((int) (time / 3600));
        for (int i = 0; i < 2; i++) {
            if (seconds.length() < 2) {
                seconds = "0" + seconds;
            }
            if (minutes.length() < 2) {
                minutes = "0" + minutes;
            }
            if (hours.length() < 2) {
                hours = "0" + hours;
            }
        }
        String timeString = hours + ":" + minutes + ":" + seconds;
        return timeString;
    }

    /**
     * It automatically restarts schedule if the new delay is less than the old one. Or waits the next schedule if the new delay is greater 
     * @param delay Milliseconds (1000 = 1 second)
     */
    public void setDelay(int delay) {
        if (delay != this.delay)
            logger.info("New delay is: " + getElapsedTimeHoursMinutesSecondsString(delay));
        if (delay < this.delay) {
            scheduledFuture.cancel(true);
            reset(delay);
        }
        this.delay = delay;
    }

    /**
     * Immediately restarts schedule
     * @param delay Milliseconds (1000 = 1 second)
     */
    public void reset(int delay) {
        this.delay = delay;
        scheduledFuture = scheduler.schedule(task, this);
    }

    /**
     * @return Date next execution of the schedule
     */
    @Override
    public Date nextExecutionTime(TriggerContext triggerContext) {
        Date lastTime = triggerContext.lastActualExecutionTime();
        Date nextExecutionTime = (lastTime == null) ? new Date() : new Date(lastTime.getTime() + delay);
        logger.info("End of schedule. Next execution: " + nextExecutionTime + ". Delay is: "
                + getElapsedTimeHoursMinutesSecondsString(delay));
        return nextExecutionTime;
    }

}