| /* |
| * Copyright 2014-present Facebook, Inc. |
| * |
| * Licensed 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. |
| */ |
| |
| /*************** |
| * |
| * This code can be embedded in arbitrary third-party projects! |
| * For maximum compatibility, use only Java 6 constructs. |
| * |
| ***************/ |
| |
| package com.facebook.buck.java; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.file.FileVisitResult; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| import java.nio.file.Paths; |
| import java.nio.file.SimpleFileVisitor; |
| import java.nio.file.attribute.BasicFileAttributes; |
| import java.nio.file.attribute.FileAttribute; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| |
| public class FatJarMain { |
| |
| private FatJarMain() {} |
| |
| /** |
| * Update the library search path environment variable with the given native library directory. |
| */ |
| private static void updateEnvironment(Map<String, String> env, Path libDir) { |
| String librarySearchPathName = getLibrarySearchPathName(); |
| String originalLibPath = System.getenv(librarySearchPathName); |
| String newlibPath = |
| libDir.toString() + (originalLibPath == null ? "" : File.pathSeparator + originalLibPath); |
| env.put(librarySearchPathName, newlibPath); |
| } |
| |
| /** |
| * @return a command to start a new JVM process to execute the given main class. |
| */ |
| private static List<String> getCommand(Path jar, String[] args) throws Exception { |
| List<String> cmd = new ArrayList<String>(); |
| // Lookup the Java binary used to start us. |
| cmd.add(Paths.get(System.getProperty("java.home")).resolve("bin").resolve("java").toString()); |
| cmd.add("-jar"); |
| // Lookup our current JAR context. |
| cmd.add(jar.toString()); |
| Collections.addAll(cmd, args); |
| return cmd; |
| } |
| |
| public static void main(String[] args) throws Exception { |
| Class<?> clazz = FatJarMain.class; |
| ClassLoader classLoader = clazz.getClassLoader(); |
| |
| // Load the fat jar info from it's resource. |
| FatJar fatJar = FatJar.load(classLoader); |
| |
| ManagedTemporaryDirectory temp = new ManagedTemporaryDirectory("fatjar."); |
| |
| // Create a temp dir to house the native libraries. |
| try { |
| |
| // Unpack the real, inner JAR. |
| Path jar = temp.getPath().resolve("main.jar"); |
| fatJar.unpackJarTo(classLoader, jar); |
| |
| // Unpack all the native libraries, since the system loader will need to find these |
| // on disk. |
| Path nativeLibs = temp.getPath().resolve("nativelibs"); |
| Files.createDirectory(nativeLibs); |
| fatJar.unpackNativeLibrariesInto(classLoader, temp.getPath()); |
| |
| // Update the appropriate environment variable with the location of our native libraries |
| // and start the real main class in a new process so that it picks it up. |
| ProcessBuilder builder = new ProcessBuilder(); |
| builder.command(getCommand(jar, args)); |
| updateEnvironment(builder.environment(), temp.getPath()); |
| builder.inheritIO(); |
| |
| // Wait for the inner process to finish, and propagate it's exit code, before cleaning |
| // up the native libraries. |
| System.exit(builder.start().waitFor()); |
| } finally { |
| temp.close(); |
| } |
| } |
| |
| /** |
| * @return the platform specific environment variable for setting the native library search path. |
| */ |
| private static String getLibrarySearchPathName() { |
| String platform = System.getProperty("os.name"); |
| if (platform.startsWith("Linux")) { |
| return "LD_LIBRARY_PATH"; |
| } else if (platform.startsWith("Mac OS")) { |
| return "DYLD_LIBRARY_PATH"; |
| } else if (platform.startsWith("Windows")) { |
| return "PATH"; |
| } else { |
| System.err.println( |
| "WARNING: using \"LD_LIBRARY_PATH\" for unrecognized platform " + platform); |
| return "LD_LIBRARY_PATH"; |
| } |
| } |
| |
| /** |
| * A temporary directory that automatically cleans itself up when used via a try-resource block. |
| */ |
| private static class ManagedTemporaryDirectory implements AutoCloseable { |
| |
| private final Path path; |
| |
| private ManagedTemporaryDirectory(Path path) { |
| this.path = path; |
| } |
| |
| public ManagedTemporaryDirectory(String prefix, FileAttribute<?>... attrs) throws IOException { |
| this(Files.createTempDirectory(prefix, attrs)); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| Files.walkFileTree( |
| path, |
| new SimpleFileVisitor<Path>() { |
| |
| @Override |
| public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) |
| throws IOException { |
| Files.delete(file); |
| return FileVisitResult.CONTINUE; |
| } |
| |
| @Override |
| public FileVisitResult postVisitDirectory(Path dir, IOException e) throws IOException { |
| if (e != null) { |
| throw e; |
| } |
| Files.delete(dir); |
| return FileVisitResult.CONTINUE; |
| } |
| |
| }); |
| } |
| |
| public Path getPath() { |
| return path; |
| } |
| |
| } |
| |
| } |