com.netflix.config.FixedDelayPollingScheduler Maven / Gradle / Ivy
/**
* Copyright 2014 Netflix, Inc.
*
* 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.netflix.config;
/**
* A polling scheduler that schedule the polling with fixed delay. This class relies
* on java.util.concurrent.ScheduledExecutorService to do the scheduling.
*
* @author awang
*/
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
public class FixedDelayPollingScheduler extends AbstractPollingScheduler {
private ScheduledExecutorService executor;
private int initialDelayMillis = 30000;
private int delayMillis = 60000;
/**
* System property name to define the initial delay in milliseconds.
*/
public static final String INITIAL_DELAY_PROPERTY = "archaius.fixedDelayPollingScheduler.initialDelayMills";
/**
* System property name to define the delay in milliseconds.
*/
public static final String DELAY_PROPERTY = "archaius.fixedDelayPollingScheduler.delayMills";
/**
* Create an instance with initial delay and delay defined in system properties
* {@value #INITIAL_DELAY_PROPERTY} and {@value #DELAY_PROPERTY}
* The scheduler will delete the property in a configuration if it is absent from the configuration source.
*/
public FixedDelayPollingScheduler() {
String initialDelayProperty = System.getProperty(INITIAL_DELAY_PROPERTY);
if (initialDelayProperty != null && initialDelayProperty.length() > 0) {
initialDelayMillis = Integer.parseInt(initialDelayProperty);
}
String delayProperty = System.getProperty(DELAY_PROPERTY);
if (delayProperty != null && delayProperty.length() > 0) {
delayMillis = Integer.parseInt(delayProperty);
}
}
/**
*
* @param initialDelayMillis initial delay in milliseconds
* @param delayMillis delay in milliseconds
* @param ignoreDeletesFromSource whether the scheduler should ignore deletes of properties from configuration source when
* applying the polling result to a configuration.
*/
public FixedDelayPollingScheduler(int initialDelayMillis, int delayMillis, boolean ignoreDeletesFromSource) {
super(ignoreDeletesFromSource);
this.initialDelayMillis = initialDelayMillis;
this.delayMillis = delayMillis;
}
/**
* This method is implemented with
* {@link java.util.concurrent.ScheduledExecutorService#scheduleWithFixedDelay(Runnable, long, long, TimeUnit)}
*/
@Override
protected synchronized void schedule(Runnable runnable) {
executor = Executors.newScheduledThreadPool(1, new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread t = new Thread(r, "pollingConfigurationSource");
t.setDaemon(true);
return t;
}
});
executor.scheduleWithFixedDelay(runnable, initialDelayMillis, delayMillis, TimeUnit.MILLISECONDS);
}
@Override
public void stop() {
if (executor != null) {
executor.shutdown();
executor = null;
}
}
}