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.gobblin.config.store.hdfs; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Optional; import com.google.common.base.Strings; import com.typesafe.config.Config; import com.typesafe.config.ConfigFactory; import org.apache.gobblin.config.store.api.ConfigStoreCreationException; import org.apache.gobblin.config.store.api.ConfigStoreFactory; import org.apache.gobblin.util.ConfigUtils; /** * An implementation of {@link ConfigStoreFactory} for creating {@link SimpleHadoopFilesystemConfigStore}s. This class only works * the physical scheme {@link #HDFS_SCHEME_NAME}. * * @see SimpleHadoopFilesystemConfigStore */ public class SimpleHDFSConfigStoreFactory extends SimpleHadoopFilesystemConfigStoreFactory { protected static final String HDFS_SCHEME_NAME = "hdfs"; /** Instantiates a new instance using standard typesafe config defaults: * {@link ConfigFactory#load()} */ public SimpleHDFSConfigStoreFactory() { this(ConfigUtils.getConfigOrEmpty(ConfigFactory.load(), DEFAULT_CONFIG_NAMESPACE)); } /** * Instantiates a new instance of the factory with the specified config. The configuration is * expected to be scoped, i.e. the properties should not be prefixed. */ public SimpleHDFSConfigStoreFactory(Config factoryConfig) { super(factoryConfig); } @Override protected FileSystem getDefaultStoreFs(Config factoryConfig, Optional<URI> configDefinedDefaultURI) { try { if (configDefinedDefaultURI.isPresent() && configDefinedDefaultURI.get().getAuthority() != null) { return FileSystem.get(configDefinedDefaultURI.get(), new Configuration()); } else { FileSystem fs = FileSystem.get(new Configuration()); return HDFS_SCHEME_NAME.equals(fs.getScheme()) ? fs : null; } } catch (IOException ioe) { throw new RuntimeException("Could not create default store fs for scheme " + getScheme()); } } @Override protected URI getDefaultRootDir(Config factoryConfig, FileSystem defaultFileSystem, Optional<URI> configDefinedDefaultURI) { return configDefinedDefaultURI.or(defaultFileSystem.getHomeDirectory().toUri()); } @Override protected String getPhysicalScheme() { return HDFS_SCHEME_NAME; } }