Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.twitter.distributedlog.config; import com.google.common.collect.Lists; import com.twitter.distributedlog.DistributedLogConfiguration; import org.apache.commons.configuration.event.ConfigurationEvent; import org.apache.commons.configuration.event.ConfigurationListener; import org.jmock.lib.concurrent.DeterministicScheduler; import org.junit.Test; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.List; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; import java.util.concurrent.atomic.AtomicReference; import static org.junit.Assert.*; /** * Notes: * 1. lastModified granularity is platform dependent, generally 1 sec, so we can't wait 1ms for things to * get picked up. */ public class TestConfigurationSubscription { static final Logger LOG = LoggerFactory.getLogger(TestConfigurationSubscription.class); /** * Give FileChangedReloadingStrategy some time to start reloading * Make sure now!=lastChecked * {@link org.apache.commons.configuration.reloading.FileChangedReloadingStrategy#reloadingRequired()} */ private void ensureConfigReloaded() throws InterruptedException { // sleep 1 ms so that System.currentTimeMillis() != // lastChecked (the time we construct FileChangedReloadingStrategy Thread.sleep(1); } @Test(timeout = 60000) public void testReloadConfiguration() throws Exception { PropertiesWriter writer = new PropertiesWriter(); FileConfigurationBuilder builder = new PropertiesConfigurationBuilder(writer.getFile().toURI().toURL()); ConcurrentConstConfiguration conf = new ConcurrentConstConfiguration(new DistributedLogConfiguration()); DeterministicScheduler executorService = new DeterministicScheduler(); List<FileConfigurationBuilder> fileConfigBuilders = Lists.newArrayList(builder); ConfigurationSubscription confSub = new ConfigurationSubscription(conf, fileConfigBuilders, executorService, 100, TimeUnit.MILLISECONDS); final AtomicReference<ConcurrentBaseConfiguration> confHolder = new AtomicReference<>(); confSub.registerListener(new com.twitter.distributedlog.config.ConfigurationListener() { @Override public void onReload(ConcurrentBaseConfiguration conf) { confHolder.set(conf); } }); assertEquals(null, conf.getProperty("prop1")); // add writer.setProperty("prop1", "1"); writer.save(); // ensure the file change reloading event can be triggered ensureConfigReloaded(); // reload the config confSub.reload(); assertNotNull(confHolder.get()); assertTrue(conf == confHolder.get()); assertEquals("1", conf.getProperty("prop1")); } @Test(timeout = 60000) public void testAddReloadBasicsConfig() throws Exception { PropertiesWriter writer = new PropertiesWriter(); DeterministicScheduler mockScheduler = new DeterministicScheduler(); FileConfigurationBuilder builder = new PropertiesConfigurationBuilder(writer.getFile().toURI().toURL()); ConcurrentConstConfiguration conf = new ConcurrentConstConfiguration(new DistributedLogConfiguration()); List<FileConfigurationBuilder> fileConfigBuilders = Lists.newArrayList(builder); ConfigurationSubscription confSub = new ConfigurationSubscription(conf, fileConfigBuilders, mockScheduler, 100, TimeUnit.MILLISECONDS); assertEquals(null, conf.getProperty("prop1")); // add writer.setProperty("prop1", "1"); writer.save(); // ensure the file change reloading event can be triggered ensureConfigReloaded(); mockScheduler.tick(100, TimeUnit.MILLISECONDS); assertEquals("1", conf.getProperty("prop1")); } @Test(timeout = 60000) public void testInitialConfigLoad() throws Exception { PropertiesWriter writer = new PropertiesWriter(); writer.setProperty("prop1", "1"); writer.setProperty("prop2", "abc"); writer.setProperty("prop3", "123.0"); writer.setProperty("prop4", "11132"); writer.setProperty("prop5", "true"); writer.save(); ScheduledExecutorService mockScheduler = new DeterministicScheduler(); FileConfigurationBuilder builder = new PropertiesConfigurationBuilder(writer.getFile().toURI().toURL()); ConcurrentConstConfiguration conf = new ConcurrentConstConfiguration(new DistributedLogConfiguration()); List<FileConfigurationBuilder> fileConfigBuilders = Lists.newArrayList(builder); ConfigurationSubscription confSub = new ConfigurationSubscription(conf, fileConfigBuilders, mockScheduler, 100, TimeUnit.MILLISECONDS); assertEquals(1, conf.getInt("prop1")); assertEquals("abc", conf.getString("prop2")); assertEquals(123.0, conf.getFloat("prop3"), 0); assertEquals(11132, conf.getInt("prop4")); assertEquals(true, conf.getBoolean("prop5")); } @Test(timeout = 60000) public void testExceptionInConfigLoad() throws Exception { PropertiesWriter writer = new PropertiesWriter(); writer.setProperty("prop1", "1"); writer.save(); DeterministicScheduler mockScheduler = new DeterministicScheduler(); FileConfigurationBuilder builder = new PropertiesConfigurationBuilder(writer.getFile().toURI().toURL()); ConcurrentConstConfiguration conf = new ConcurrentConstConfiguration(new DistributedLogConfiguration()); List<FileConfigurationBuilder> fileConfigBuilders = Lists.newArrayList(builder); ConfigurationSubscription confSub = new ConfigurationSubscription(conf, fileConfigBuilders, mockScheduler, 100, TimeUnit.MILLISECONDS); final AtomicInteger count = new AtomicInteger(1); conf.addConfigurationListener(new ConfigurationListener() { @Override public void configurationChanged(ConfigurationEvent event) { LOG.info("config changed {}", event); // Throw after so we actually see the update anyway. if (!event.isBeforeUpdate()) { count.getAndIncrement(); throw new RuntimeException("config listener threw and exception"); } } }); int i = 0; int initial = 0; while (count.get() == initial) { writer.setProperty("prop1", Integer.toString(i++)); writer.save(); mockScheduler.tick(100, TimeUnit.MILLISECONDS); } initial = count.get(); while (count.get() == initial) { writer.setProperty("prop1", Integer.toString(i++)); writer.save(); mockScheduler.tick(100, TimeUnit.MILLISECONDS); } } }