    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
    015package org.apache.tapestry5.ioc.services.cron;
    016
    017import org.apache.tapestry5.ioc.internal.services.cron.CronExpression;
    018
    019import java.text.ParseException;
    020import java.util.Date;
    021import java.util.TimeZone;
    022
    023public class CronSchedule implements Schedule
    024{
    025    private CronExpression cron;
    026
    027    public CronSchedule(String cronExpression)
    028    {
    029        this(cronExpression, TimeZone.getDefault());
    030    }
    031
    032    public CronSchedule(String cronExpression, TimeZone timeZone)
    033    {
    034        try
    035        {
    036            this.cron = new CronExpression(cronExpression);
    037            this.cron.setTimeZone(timeZone);
    038        } catch (ParseException e)
    039        {
    040            throw new RuntimeException(e);
    041        }
    042    }
    043
    044    @Override
    045    public long firstExecution()
    046    {
    047        return getNextValidTimeAfterNow();
    048    }
    049
    050    @Override
    051    public long nextExecution(long previousExecution)
    052    {
    053        return getNextValidTimeAfterNow();
    054    }
    055
    056    private long getNextValidTimeAfterNow()
    057    {
    058        final Date time = cron.getNextValidTimeAfter(new Date());
    059
    060        return time == null ? 0 : time.getTime();
    061    }
    062}