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.metron.common.utils; import org.apache.accumulo.start.classloader.vfs.UniqueFileReplicator; import org.apache.commons.vfs2.*; import org.apache.commons.vfs2.cache.SoftRefFilesCache; import org.apache.commons.vfs2.impl.DefaultFileSystemManager; import org.apache.commons.vfs2.impl.FileContentInfoFilenameFactory; import org.apache.commons.vfs2.impl.VFSClassLoader; import org.apache.commons.vfs2.provider.hdfs.HdfsFileProvider; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.File; import java.util.*; public class VFSClassloaderUtil { private static final Logger LOG = LoggerFactory.getLogger(VFSClassloaderUtil.class); /** * Create a FileSystem manager suitable for our purposes. * This manager supports files of the following types: * * res - resource files * * jar * * tar * * bz2 * * tgz * * zip * * HDFS * * FTP * * HTTP/S * * file * @return * @throws FileSystemException */ public static FileSystemManager generateVfs() throws FileSystemException { DefaultFileSystemManager vfs = new DefaultFileSystemManager(); vfs.addProvider("res", new org.apache.commons.vfs2.provider.res.ResourceFileProvider()); vfs.addProvider("zip", new org.apache.commons.vfs2.provider.zip.ZipFileProvider()); vfs.addProvider("gz", new org.apache.commons.vfs2.provider.gzip.GzipFileProvider()); vfs.addProvider("ram", new org.apache.commons.vfs2.provider.ram.RamFileProvider()); vfs.addProvider("file", new org.apache.commons.vfs2.provider.local.DefaultLocalFileProvider()); vfs.addProvider("jar", new org.apache.commons.vfs2.provider.jar.JarFileProvider()); vfs.addProvider("http", new org.apache.commons.vfs2.provider.http.HttpFileProvider()); vfs.addProvider("https", new org.apache.commons.vfs2.provider.https.HttpsFileProvider()); vfs.addProvider("ftp", new org.apache.commons.vfs2.provider.ftp.FtpFileProvider()); vfs.addProvider("ftps", new org.apache.commons.vfs2.provider.ftps.FtpsFileProvider()); vfs.addProvider("war", new org.apache.commons.vfs2.provider.jar.JarFileProvider()); vfs.addProvider("par", new org.apache.commons.vfs2.provider.jar.JarFileProvider()); vfs.addProvider("ear", new org.apache.commons.vfs2.provider.jar.JarFileProvider()); vfs.addProvider("sar", new org.apache.commons.vfs2.provider.jar.JarFileProvider()); vfs.addProvider("ejb3", new org.apache.commons.vfs2.provider.jar.JarFileProvider()); vfs.addProvider("tmp", new org.apache.commons.vfs2.provider.temp.TemporaryFileProvider()); vfs.addProvider("tar", new org.apache.commons.vfs2.provider.tar.TarFileProvider()); vfs.addProvider("tbz2", new org.apache.commons.vfs2.provider.tar.TarFileProvider()); vfs.addProvider("tgz", new org.apache.commons.vfs2.provider.tar.TarFileProvider()); vfs.addProvider("bz2", new org.apache.commons.vfs2.provider.bzip2.Bzip2FileProvider()); vfs.addProvider("hdfs", new HdfsFileProvider()); vfs.addExtensionMap("jar", "jar"); vfs.addExtensionMap("zip", "zip"); vfs.addExtensionMap("gz", "gz"); vfs.addExtensionMap("tar", "tar"); vfs.addExtensionMap("tbz2", "tar"); vfs.addExtensionMap("tgz", "tar"); vfs.addExtensionMap("bz2", "bz2"); vfs.addMimeTypeMap("application/x-tar", "tar"); vfs.addMimeTypeMap("application/x-gzip", "gz"); vfs.addMimeTypeMap("application/zip", "zip"); vfs.setFileContentInfoFactory(new FileContentInfoFilenameFactory()); vfs.setFilesCache(new SoftRefFilesCache()); vfs.setReplicator(new UniqueFileReplicator(new File(System.getProperty("java.io.tmpdir")))); vfs.setCacheStrategy(CacheStrategy.ON_RESOLVE); vfs.init(); return vfs; } /** * Create a classloader backed by a virtual filesystem which can handle the following URI types: * * res - resource files * * jar * * tar * * bz2 * * tgz * * zip * * HDFS * * FTP * * HTTP/S * * file * @param paths A set of comma separated paths. The paths are URIs or URIs with a regex pattern at the end. * @return A classloader object if it can create it * @throws FileSystemException */ public static Optional<ClassLoader> configureClassloader(String paths) throws FileSystemException { if (paths.trim().isEmpty()) { return Optional.empty(); } FileSystemManager vfs = generateVfs(); FileObject[] objects = resolve(vfs, paths); if (objects == null || objects.length == 0) { return Optional.empty(); } return Optional.of(new VFSClassLoader(objects, vfs, vfs.getClass().getClassLoader())); } /** * Resolve a set of URIs into FileObject objects. * This is not recursive. The URIs can refer directly to a file or directory or an optional regex at the end. * (NOTE: This is NOT a glob). * @param vfs The file system manager to use to resolve URIs * @param uris comma separated URIs and URI + globs * @return * @throws FileSystemException */ static FileObject[] resolve(FileSystemManager vfs, String uris) throws FileSystemException { if (uris == null) { return new FileObject[0]; } ArrayList<FileObject> classpath = new ArrayList<>(); for (String path : uris.split(",")) { path = path.trim(); if (path.equals("")) { continue; } FileObject fo = vfs.resolveFile(path); switch (fo.getType()) { case FILE: case FOLDER: classpath.add(fo); break; case IMAGINARY: // assume its a pattern String pattern = fo.getName().getBaseName(); if (fo.getParent() != null && fo.getParent().getType() == FileType.FOLDER) { FileObject[] children = fo.getParent().getChildren(); for (FileObject child : children) { if (child.getType() == FileType.FILE && child.getName().getBaseName().matches(pattern)) { classpath.add(child); } } } else { LOG.warn("ignoring classpath entry " + fo); } break; default: LOG.warn("ignoring classpath entry " + fo); break; } } return classpath.toArray(new FileObject[classpath.size()]); } }