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.zip; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.URI; import java.nio.file.FileSystem; import java.nio.file.Files; import java.nio.file.Path; import java.util.ArrayList; import java.util.Collection; import java.util.Iterator; import java.util.List; import java.util.stream.Stream; import org.apache.commons.lang.StringUtils; import com.google.common.base.Charsets; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.sun.nio.zipfs.ZipFileSystem; import com.typesafe.config.Config; import com.typesafe.config.ConfigFactory; import org.apache.gobblin.config.common.impl.SingleLinkedListConfigKeyPath; import org.apache.gobblin.config.store.api.ConfigKeyPath; import org.apache.gobblin.config.store.api.ConfigStore; import org.apache.gobblin.config.store.api.VersionDoesNotExistException; import org.apache.gobblin.config.store.hdfs.SimpleHadoopFilesystemConfigStore; import lombok.extern.slf4j.Slf4j; /** * {@link ConfigStore} that uses a zipped file containing all the config store paths. * * Similar to {@link SimpleHadoopFilesystemConfigStore} but using java APIs instead of Hadoop APIs for the Filesystem to * allow reading the file without unzipping. * * It is assumed that the version passed in the constructor will be the only version used. */ @Slf4j public class ZipFileConfigStore implements ConfigStore { private final FileSystem fs; private final URI logicalStoreRoot; private String version; private String storePrefix; /** * Construct a ZipFileConfigStore * * @param fs A {@link ZipFileSystem} created using the zip file or jar containing the config store * @param logicalStoreRoot URI of this config store's root * @param version Config store version to use (only version allowed for lookups is the version passed here) * @param storePrefix Prefix to use if all paths in config store are under a parent directory */ public ZipFileConfigStore(ZipFileSystem fs, URI logicalStoreRoot, String version, String storePrefix) { Preconditions.checkNotNull(fs); Preconditions.checkNotNull(logicalStoreRoot); Preconditions.checkNotNull(version); this.fs = fs; this.logicalStoreRoot = logicalStoreRoot; this.version = version; this.storePrefix = storePrefix; } @Override public String getCurrentVersion() { return this.version; } @Override public URI getStoreURI() { return this.logicalStoreRoot; } /** * Retrieves all the children of the given {@link ConfigKeyPath} using {@link Files#walk} to list files */ @Override public Collection<ConfigKeyPath> getChildren(ConfigKeyPath configKey, String version) throws VersionDoesNotExistException { Preconditions.checkNotNull(configKey, "configKey cannot be null!"); Preconditions.checkArgument(version.equals(getCurrentVersion())); List<ConfigKeyPath> children = new ArrayList<>(); Path datasetDir = getDatasetDirForKey(configKey); try { if (!Files.exists(this.fs.getPath(datasetDir.toString()))) { return children; } Stream<Path> files = Files.walk(datasetDir, 1); for (Iterator<Path> it = files.iterator(); it.hasNext();) { Path path = it.next(); if (Files.isDirectory(path) && !path.equals(datasetDir)) { children.add(configKey .createChild(StringUtils.removeEnd(path.getName(path.getNameCount() - 1).toString(), SingleLinkedListConfigKeyPath.PATH_DELIMETER))); } } return children; } catch (IOException e) { throw new RuntimeException( String.format("Error while getting children for configKey: \"%s\"", configKey), e); } } /** * Retrieves all the {@link ConfigKeyPath}s that are imported by the given {@link ConfigKeyPath}. Similar to * {@link SimpleHadoopFilesystemConfigStore#getOwnImports} */ @Override public List<ConfigKeyPath> getOwnImports(ConfigKeyPath configKey, String version) { return getOwnImports(configKey, version, Optional.<Config>absent()); } public List<ConfigKeyPath> getOwnImports(ConfigKeyPath configKey, String version, Optional<Config> runtimeConfig) throws VersionDoesNotExistException { Preconditions.checkNotNull(configKey, "configKey cannot be null!"); Preconditions.checkArgument(version.equals(getCurrentVersion())); List<ConfigKeyPath> configKeyPaths = new ArrayList<>(); Path datasetDir = getDatasetDirForKey(configKey); Path includesFile = this.fs.getPath(datasetDir.toString(), SimpleHadoopFilesystemConfigStore.INCLUDES_CONF_FILE_NAME); try { if (!Files.exists(includesFile)) { return configKeyPaths; } if (!Files.isDirectory(includesFile)) { try (InputStream includesConfInStream = Files.newInputStream(includesFile)) { configKeyPaths = SimpleHadoopFilesystemConfigStore .getResolvedConfigKeyPaths(includesConfInStream, runtimeConfig); } } } catch (IOException e) { throw new RuntimeException(String.format("Error while getting config for configKey: \"%s\"", configKey), e); } return configKeyPaths; } /** * Retrieves the {@link Config} for the given {@link ConfigKeyPath}. Similar to * {@link SimpleHadoopFilesystemConfigStore#getOwnConfig} */ @Override public Config getOwnConfig(ConfigKeyPath configKey, String version) throws VersionDoesNotExistException { Preconditions.checkNotNull(configKey, "configKey cannot be null!"); Preconditions.checkArgument(version.equals(getCurrentVersion())); Path datasetDir = getDatasetDirForKey(configKey); Path mainConfFile = this.fs.getPath(datasetDir.toString(), SimpleHadoopFilesystemConfigStore.MAIN_CONF_FILE_NAME); try { if (!Files.exists(mainConfFile)) { return ConfigFactory.empty(); } if (!Files.isDirectory(mainConfFile)) { try (InputStream mainConfInputStream = Files.newInputStream(mainConfFile)) { return ConfigFactory.parseReader(new InputStreamReader(mainConfInputStream, Charsets.UTF_8)); } } return ConfigFactory.empty(); } catch (IOException e) { throw new RuntimeException(String.format("Error while getting config for configKey: \"%s\"", configKey), e); } } /** * Get path object using zipped file system and relative path */ private Path getDatasetDirForKey(ConfigKeyPath configKey) throws VersionDoesNotExistException { return this.fs.getPath(this.storePrefix, configKey.getAbsolutePathString()); } }