jiajunwang commented on a change in pull request #653: add Helix properties factory and class URL: https://github.com/apache/helix/pull/653#discussion_r369215470
########## File path: helix-core/src/main/java/org/apache/helix/HelixPropertyFactory.java ########## @@ -0,0 +1,80 @@ +package org.apache.helix; + +/* + * 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. + */ + +import java.io.IOException; +import java.io.InputStream; +import java.util.Properties; +import org.apache.helix.model.CloudConfig; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Singleton factory that builds different types of Helix property, e.g. Helix manager property. + */ +public final class HelixPropertyFactory { + private static final Logger LOG = LoggerFactory.getLogger(HelixPropertyFactory.class); + private static final String HELIX_PARTICIPANT_PROPERTY_FILE = + SystemPropertyKeys.HELIX_MANAGER_PROPERTIES; + + private static class SingletonHelper { + private static final HelixPropertyFactory INSTANCE = new HelixPropertyFactory(); + } + + public static HelixPropertyFactory getInstance() { + return SingletonHelper.INSTANCE; + } + + /** + * Retrieve Helix manager property. It returns the property object with default values. + * Clients may override these values. + */ + public HelixManagerProperty getHelixManagerProperty(String zkAddress, String clusterName) { + ConfigAccessor configAccessor = new ConfigAccessor(zkAddress); + CloudConfig cloudConfig; + // The try-catch logic is for backward compatibility reason only. Even if the cluster is not set + // up yet, constructing a new ZKHelixManager should not throw an exception + try { + cloudConfig = + configAccessor.getCloudConfig(clusterName) == null ? buildEmptyCloudConfig(clusterName) + : configAccessor.getCloudConfig(clusterName); + } catch (HelixException e) { + cloudConfig = buildEmptyCloudConfig(clusterName); + } + Properties properties = new Properties(); + try { + InputStream stream = Thread.currentThread().getContextClassLoader() + .getResourceAsStream(HELIX_PARTICIPANT_PROPERTY_FILE); + properties.load(stream); + } catch (IOException e) { + String errMsg = String.format("failed to open Helix participant properties file: %s", + HELIX_PARTICIPANT_PROPERTY_FILE); + LOG.error(errMsg); Review comment: nit, like I suggested above, we don't need this error to be logged since it will be thrown. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@helix.apache.org For additional commands, e-mail: reviews-h...@helix.apache.org
