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The Service Provider Interfaces for developing HiveMQ plugins.
/*
* Copyright 2014 dc-square GmbH
*
* 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 com.hivemq.spi.callback.schedule;
import static com.google.common.base.Preconditions.checkArgument;
import static java.text.MessageFormat.format;
/**
* This utility class has several methods and constants for working with quartz-style cron expressions.
*
* @author Dominik Obermaier
*/
public class ScheduleExpressions {
/**
* Returns the a Schedule Expression which schedules to the beginning of every minute
*/
public static final String ONCE_A_MINUTE = "0 0/1 * * * ?";
/**
* Returns a quartz-style cron expression which is used to schedule something every X minutes.
*
* This is useful if you want to run a scheduled callback e.g. every 10 minutes.
*
*
* @param minutes the minutes
* @return the quartz-style cron expression for the number of minutes passed
* @throws IllegalArgumentException if the number of minutes is < 1
*/
public static String everyMinutes(final int minutes) {
final String minutePattern = "0 0/{0,number,#} * * * ?";
checkArgument(minutes > 0, "Only a number of minutes > 0 can be used for scheduling. %s was provided.", minutes);
return format(minutePattern, minutes);
}
}