Java tutorial
/** * DataCleaner (community edition) * Copyright (C) 2014 Neopost - Customer Information Management * * This copyrighted material is made available to anyone wishing to use, modify, * copy, or redistribute it subject to the terms and conditions of the GNU * Lesser General Public License, as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License * for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this distribution; if not, write to: * Free Software Foundation, Inc. * 51 Franklin Street, Fifth Floor * Boston, MA 02110-1301 USA */ package org.datacleaner.user; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URL; import java.nio.file.Files; import java.nio.file.Path; import java.util.List; import org.apache.commons.vfs2.FileObject; import org.apache.commons.vfs2.FileSystemException; import org.apache.commons.vfs2.FileSystemManager; import org.apache.commons.vfs2.FileType; import org.apache.metamodel.util.FileHelper; import org.datacleaner.Version; import org.datacleaner.configuration.DataCleanerConfigurationImpl; import org.datacleaner.configuration.DataCleanerHomeFolder; import org.datacleaner.configuration.DataCleanerHomeFolderImpl; import org.datacleaner.extensions.ClassLoaderUtils; import org.datacleaner.repository.file.FileRepository; import org.datacleaner.user.upgrade.DataCleanerHomeUpgrader; import org.datacleaner.util.ResourceManager; import org.datacleaner.util.StringUtils; import org.datacleaner.util.SystemProperties; import org.datacleaner.util.VFSUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Incapsulation of the DATACLEANER_HOME folder. This folder is resolved using * the following ordered approach: * * <ol> * <li>If a DATACLEANER_HOME environment variable exists, it will be used.</li> * <li>If the application is running in Java WebStart mode, a sandbox folder * will be used.</li> * <li>If none of the above, the current folder "." will be used.</li> * </ol> */ public final class DataCleanerHome { private static final Logger logger; private static final FileObject _dataCleanerHome; static { // note: Logger is specified using a string. This is because the logger is // to be used also in the static initializer and any error in that code // would otherwise be swallowed. logger = LoggerFactory.getLogger("org.datacleaner.user.DataCleanerHome"); logger.info("Initializing DATACLEANER_HOME"); try { _dataCleanerHome = findDataCleanerHome(); } catch (Exception e) { logger.error("Failed to initialize DATACLEANER_HOME!", e); if (e instanceof RuntimeException) { throw (RuntimeException) e; } throw new IllegalStateException(e); } } private static FileObject findDataCleanerHome() throws FileSystemException { final FileSystemManager manager = VFSUtils.getFileSystemManager(); FileObject candidate = null; String path = System.getenv("DATACLEANER_HOME"); if (!StringUtils.isNullOrEmpty(path)) { logger.info("Resolved env. variable DATACLEANER_HOME: {}", path); } else { path = System.getProperty("DATACLEANER_HOME"); if (!StringUtils.isNullOrEmpty(path)) { candidate = manager.resolveFile(path); logger.info("Resolved system property DATACLEANER_HOME: {}", path, candidate); } } if (!StringUtils.isNullOrEmpty(path)) { if (path.startsWith("~")) { String userHomePath = System.getProperty("user.home"); path = path.replace("~", userHomePath); } candidate = manager.resolveFile(path); } if (isUsable(candidate)) { // Found a directory with conf.xml already there return candidate; } else { return initializeDataCleanerHome(candidate); } } private static FileObject initializeDataCleanerHome(FileObject candidate) throws FileSystemException { final FileSystemManager manager = VFSUtils.getFileSystemManager(); if (ClassLoaderUtils.IS_WEB_START) { // in web start, the default folder will be in user.home final String path = getUserHomeCandidatePath(); candidate = manager.resolveFile(path); logger.info("Running in WebStart mode. Attempting to build DATACLEANER_HOME in user.home: {} -> {}", path, candidate); } else { // in normal mode try to use specified directory first logger.info("Running in standard mode."); if (isWriteable(candidate)) { logger.info("Attempting to build DATACLEANER_HOME in {}", candidate); } else { // Workaround: isWritable is not reliable for a non-existent // directory. Trying to create it, if it does not exist. if ((candidate != null) && (!candidate.exists())) { logger.info("Folder {} does not exist. Trying to create it.", candidate); try { candidate.createFolder(); logger.info("Folder {} created successfully. Attempting to build DATACLEANER_HOME here.", candidate); } catch (FileSystemException e) { logger.info("Unable to create folder {}. No write permission in that location.", candidate); candidate = initializeDataCleanerHomeFallback(); } } else { candidate = initializeDataCleanerHomeFallback(); } } } if ("true".equalsIgnoreCase(System.getProperty(SystemProperties.SANDBOX))) { logger.info("Running in sandbox mode ({}), setting {} as DATACLEANER_HOME", SystemProperties.SANDBOX, candidate); if (!candidate.exists()) { candidate.createFolder(); } return candidate; } if (!isUsable(candidate)) { DataCleanerHomeUpgrader upgrader = new DataCleanerHomeUpgrader(); boolean upgraded = upgrader.upgrade(candidate); if (!upgraded) { logger.debug("Copying default configuration and examples to DATACLEANER_HOME directory: {}", candidate); copyIfNonExisting(candidate, manager, "conf.xml"); final List<String> allFilePaths = DemoConfiguration.getAllFilePaths(); for (String filePath : allFilePaths) { copyIfNonExisting(candidate, manager, filePath); } } } return candidate; } private static FileObject initializeDataCleanerHomeFallback() throws FileSystemException { final FileSystemManager manager = VFSUtils.getFileSystemManager(); FileObject candidate; // Fallback to user home directory final String path = getUserHomeCandidatePath(); candidate = manager.resolveFile(path); logger.info("Attempting to build DATACLEANER_HOME in user.home: {} -> {}", path, candidate); if (!isWriteable(candidate)) { // Workaround: isWritable is not reliable for a non-existent // directory. Trying to create it, if it does not exist. if ((candidate != null) && (!candidate.exists())) { logger.info("Folder {} does not exist. Trying to create it.", candidate); try { candidate.createFolder(); logger.info("Folder {} created successfully. Attempting to build DATACLEANER_HOME here.", candidate); } catch (FileSystemException e) { logger.info("Unable to create folder {}. No write permission in that location.", candidate); throw new IllegalStateException("User home directory (" + candidate + ") is not writable. DataCleaner requires write access to its home directory."); } } } return candidate; } private static boolean isWriteable(FileObject candidate) throws FileSystemException { if (candidate == null) { return false; } if (!candidate.isWriteable()) { return false; } // check with java.nio.Files.isWriteable() - is more detailed in it's // check final File file = VFSUtils.toFile(candidate); final Path path = file.toPath(); return Files.isWritable(path); } /** * @return a file reference to the DataCleaner home folder. */ public static FileObject get() { return _dataCleanerHome; } public static DataCleanerHomeFolder getAsDataCleanerHomeFolder() { final File file = getAsFile(); if (file == null) { return DataCleanerConfigurationImpl.defaultHomeFolder(); } final FileRepository fileRepository = new FileRepository(file); return new DataCleanerHomeFolderImpl(fileRepository); } public static File getAsFile() { return VFSUtils.toFile(_dataCleanerHome); } private static FileObject copyIfNonExisting(FileObject candidate, FileSystemManager manager, String filename) throws FileSystemException { FileObject file = candidate.resolveFile(filename); if (file.exists()) { logger.info("File already exists in DATACLEANER_HOME: " + filename); return file; } FileObject parentFile = file.getParent(); if (!parentFile.exists()) { parentFile.createFolder(); } final ResourceManager resourceManager = ResourceManager.get(); final URL url = resourceManager.getUrl("datacleaner-home/" + filename); if (url == null) { return null; } InputStream in = null; OutputStream out = null; try { in = url.openStream(); out = file.getContent().getOutputStream(); FileHelper.copy(in, out); } catch (IOException e) { throw new IllegalArgumentException(e); } finally { FileHelper.safeClose(in, out); } return file; } private static String getUserHomeCandidatePath() { final String userHomePath = System.getProperty("user.home"); final String path = userHomePath + File.separatorChar + ".datacleaner" + File.separatorChar + Version.getVersion(); return path; } private static boolean isUsable(FileObject candidate) throws FileSystemException { if (candidate != null) { if (candidate.exists() && candidate.getType() == FileType.FOLDER) { FileObject conf = candidate.resolveFile("conf.xml"); if (conf.exists() && conf.getType() == FileType.FILE) { return true; } } } return false; } }