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 org.apache.jackrabbit.oak.run.osgi; import java.io.File; import java.io.IOException; import java.util.List; import java.util.Map; import java.util.Set; import com.google.common.base.Charsets; import com.google.common.base.Splitter; import com.google.common.collect.Maps; import com.google.common.collect.Sets; import com.google.common.io.Files; import org.json.simple.JSONObject; import org.json.simple.JSONValue; import org.osgi.framework.BundleContext; import org.osgi.framework.ServiceReference; import org.osgi.service.cm.ConfigurationAdmin; import org.osgi.util.tracker.ServiceTracker; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Installs config obtained from JSON Config file or passed as part of * startup */ class ConfigTracker extends ServiceTracker<ConfigurationAdmin, ConfigurationAdmin> { private final Logger log = LoggerFactory.getLogger(getClass()); private final Map config; private final BundleContext bundleContext; public ConfigTracker(Map config, BundleContext bundleContext) { super(bundleContext, ConfigurationAdmin.class.getName(), null); this.config = config; this.bundleContext = bundleContext; open(); } @Override public ConfigurationAdmin addingService(ServiceReference<ConfigurationAdmin> reference) { ConfigurationAdmin cm = super.addingService(reference); try { synchronizeConfigs(new ConfigInstaller(cm, bundleContext)); } catch (Exception e) { log.error("Error occurred while installing configs", e); throw new RuntimeException(e); } return cm; } /** * Synchronizes the configs. All config added by this class is also kept in sync with re runs * i.e. if a config was added in first run and say later removed then that would also be removed * from the ConfigurationAdmin */ private void synchronizeConfigs(ConfigInstaller configInstaller) throws Exception { Set<String> existingPids = configInstaller.determineExistingConfigs(); Map<String, Map<String, Object>> configs = Maps.newHashMap(); Map<String, Map<String, Object>> configFromFile = parseJSONConfig( (String) config.get(OakOSGiRepositoryFactory.REPOSITORY_CONFIG_FILE)); configs.putAll(configFromFile); @SuppressWarnings("unchecked") Map<String, Map<String, Object>> runtimeConfig = (Map<String, Map<String, Object>>) config .get(OakOSGiRepositoryFactory.REPOSITORY_CONFIG); if (runtimeConfig != null) { configs.putAll(runtimeConfig); } configInstaller.installConfigs(configs); //Find out the config *installed by ConfigInstaller* and are not present in //current config files. Such configs must be remove. Note it does not lead to //removal of configs added by using ConfigAdmin directly, say using WebConsole //ui Set<String> pidsToBeRemoved = Sets.difference(existingPids, configs.keySet()); configInstaller.removeConfigs(pidsToBeRemoved); } @SuppressWarnings("unchecked") private Map<String, Map<String, Object>> parseJSONConfig(String jsonFilePath) throws IOException { Map<String, Map<String, Object>> configs = Maps.newHashMap(); if (jsonFilePath == null) { return configs; } List<String> files = Splitter.on(',').trimResults().omitEmptyStrings().splitToList(jsonFilePath); for (String filePath : files) { File jsonFile = new File(filePath); if (!jsonFile.exists()) { log.warn("No file found at path {}. Ignoring the file entry", jsonFile.getAbsolutePath()); continue; } String content = Files.toString(jsonFile, Charsets.UTF_8); JSONObject json = (JSONObject) JSONValue.parse(content); configs.putAll(json); } return configs; } }