Java tutorial
/******************************************************************************* * Copyright 2011 See AUTHORS file. * * 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. ******************************************************************************/ package com.badlogic.gdx.utils; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.lang.reflect.Method; import java.util.HashSet; import java.util.UUID; import java.util.zip.CRC32; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; /** Loads shared libraries from a natives jar file (desktop) or arm folders (Android). For desktop projects, have the natives jar * in the classpath, for Android projects put the shared libraries in the libs/armeabi and libs/armeabi-v7a folders. * @author mzechner * @author Nathan Sweet */ public class SharedLibraryLoader { static public boolean isWindows = System.getProperty("os.name").contains("Windows"); static public boolean isLinux = System.getProperty("os.name").contains("Linux"); static public boolean isMac = System.getProperty("os.name").contains("Mac"); static public boolean isIos = false; static public boolean isAndroid = false; static public boolean isARM = System.getProperty("os.arch").startsWith("arm"); static public boolean is64Bit = System.getProperty("os.arch").equals("amd64") || System.getProperty("os.arch").equals("x86_64"); // JDK 8 only. static public String abi = (System.getProperty("sun.arch.abi") != null ? System.getProperty("sun.arch.abi") : ""); static { String vm = System.getProperty("java.runtime.name"); if (vm != null && vm.contains("Android Runtime")) { isAndroid = true; isWindows = false; isLinux = false; isMac = false; is64Bit = false; } if (!isAndroid && !isWindows && !isLinux && !isMac) { isIos = true; is64Bit = false; } } static private final HashSet<String> loadedLibraries = new HashSet(); private String nativesJar; public SharedLibraryLoader() { } /** Fetches the natives from the given natives jar file. Used for testing a shared lib on the fly. * @param nativesJar */ public SharedLibraryLoader(String nativesJar) { this.nativesJar = nativesJar; } /** Returns a CRC of the remaining bytes in the stream. */ public String crc(InputStream input) { if (input == null) throw new IllegalArgumentException("input cannot be null."); CRC32 crc = new CRC32(); byte[] buffer = new byte[4096]; try { while (true) { int length = input.read(buffer); if (length == -1) break; crc.update(buffer, 0, length); } } catch (Exception ex) { StreamUtils.closeQuietly(input); } return Long.toString(crc.getValue(), 16); } /** Maps a platform independent library name to a platform dependent name. */ public String mapLibraryName(String libraryName) { if (isWindows) return libraryName + (is64Bit ? "64.dll" : ".dll"); if (isLinux) return "lib" + libraryName + (isARM ? "arm" + abi : "") + (is64Bit ? "64.so" : ".so"); if (isMac) return "lib" + libraryName + (is64Bit ? "64.dylib" : ".dylib"); return libraryName; } /** Loads a shared library for the platform the application is running on. * @param libraryName The platform independent library name. If not contain a prefix (eg lib) or suffix (eg .dll). */ public synchronized void load(String libraryName) { // in case of iOS, things have been linked statically to the executable, bail out. if (isIos) return; libraryName = mapLibraryName(libraryName); if (loadedLibraries.contains(libraryName)) return; try { if (isAndroid) System.loadLibrary(libraryName); else loadFile(libraryName); } catch (Throwable ex) { throw new GdxRuntimeException("Couldn't load shared library '" + libraryName + "' for target: " + System.getProperty("os.name") + (is64Bit ? ", 64-bit" : ", 32-bit"), ex); } loadedLibraries.add(libraryName); } private InputStream readFile(String path) { if (nativesJar == null) { InputStream input = SharedLibraryLoader.class.getResourceAsStream("/" + path); if (input == null) throw new GdxRuntimeException("Unable to read file for extraction: " + path); return input; } // Read from JAR. try { ZipFile file = new ZipFile(nativesJar); ZipEntry entry = file.getEntry(path); if (entry == null) throw new GdxRuntimeException("Couldn't find '" + path + "' in JAR: " + nativesJar); return file.getInputStream(entry); } catch (IOException ex) { throw new GdxRuntimeException("Error reading '" + path + "' in JAR: " + nativesJar, ex); } } /** Extracts the specified file into the temp directory if it does not already exist or the CRC does not match. If file * extraction fails and the file exists at java.library.path, that file is returned. * @param sourcePath The file to extract from the classpath or JAR. * @param dirName The name of the subdirectory where the file will be extracted. If null, the file's CRC will be used. * @return The extracted file. */ public File extractFile(String sourcePath, String dirName) throws IOException { try { String sourceCrc = crc(readFile(sourcePath)); if (dirName == null) dirName = sourceCrc; File extractedFile = getExtractedFile(dirName, new File(sourcePath).getName()); return extractFile(sourcePath, sourceCrc, extractedFile); } catch (RuntimeException ex) { // Fallback to file at java.library.path location, eg for applets. File file = new File(System.getProperty("java.library.path"), sourcePath); if (file.exists()) return file; throw ex; } } /** Returns a path to a file that can be written. Tries multiple locations and verifies writing succeeds. */ private File getExtractedFile(String dirName, String fileName) { // Temp directory with username in path. File idealFile = new File( System.getProperty("java.io.tmpdir") + "/libgdx" + System.getProperty("user.name") + "/" + dirName, fileName); if (canWrite(idealFile)) return idealFile; // System provided temp directory. try { File file = File.createTempFile(dirName, null); if (file.delete()) { file = new File(file, fileName); if (canWrite(file)) return file; } } catch (IOException ignored) { } // User home. File file = new File(System.getProperty("user.home") + "/.libgdx/" + dirName, fileName); if (canWrite(file)) return file; // Relative directory. file = new File(".temp/" + dirName, fileName); if (canWrite(file)) return file; return idealFile; // Will likely fail, but we did our best. } /** Returns true if the parent directories of the file can be created and the file can be written. */ private boolean canWrite(File file) { File parent = file.getParentFile(); File testFile; if (file.exists()) { if (!file.canWrite() || !canExecute(file)) return false; // Don't overwrite existing file just to check if we can write to directory. testFile = new File(parent, UUID.randomUUID().toString()); } else { parent.mkdirs(); if (!parent.isDirectory()) return false; testFile = file; } try { new FileOutputStream(testFile).close(); if (!canExecute(testFile)) return false; return true; } catch (Throwable ex) { return false; } finally { testFile.delete(); } } private boolean canExecute(File file) { try { Method canExecute = File.class.getMethod("canExecute"); if ((Boolean) canExecute.invoke(file)) return true; Method setExecutable = File.class.getMethod("setExecutable", boolean.class, boolean.class); setExecutable.invoke(file, true, false); return (Boolean) canExecute.invoke(file); } catch (Exception ignored) { } return false; } private File extractFile(String sourcePath, String sourceCrc, File extractedFile) throws IOException { String extractedCrc = null; if (extractedFile.exists()) { try { extractedCrc = crc(new FileInputStream(extractedFile)); } catch (FileNotFoundException ignored) { } } // If file doesn't exist or the CRC doesn't match, extract it to the temp dir. if (extractedCrc == null || !extractedCrc.equals(sourceCrc)) { try { InputStream input = readFile(sourcePath); extractedFile.getParentFile().mkdirs(); FileOutputStream output = new FileOutputStream(extractedFile); byte[] buffer = new byte[4096]; while (true) { int length = input.read(buffer); if (length == -1) break; output.write(buffer, 0, length); } input.close(); output.close(); } catch (IOException ex) { throw new GdxRuntimeException( "Error extracting file: " + sourcePath + "\nTo: " + extractedFile.getAbsolutePath(), ex); } } return extractedFile; } /** Extracts the source file and calls System.load. Attemps to extract and load from multiple locations. Throws runtime * exception if all fail. */ private void loadFile(String sourcePath) { String sourceCrc = crc(readFile(sourcePath)); String fileName = new File(sourcePath).getName(); // Temp directory with username in path. File file = new File(System.getProperty("java.io.tmpdir") + "/libgdx" + System.getProperty("user.name") + "/" + sourceCrc, fileName); Throwable ex = loadFile(sourcePath, sourceCrc, file); if (ex == null) return; // System provided temp directory. try { file = File.createTempFile(sourceCrc, null); if (file.delete() && loadFile(sourcePath, sourceCrc, file) == null) return; } catch (Throwable ignored) { } // User home. file = new File(System.getProperty("user.home") + "/.libgdx/" + sourceCrc, fileName); if (loadFile(sourcePath, sourceCrc, file) == null) return; // Relative directory. file = new File(".temp/" + sourceCrc, fileName); if (loadFile(sourcePath, sourceCrc, file) == null) return; // Fallback to java.library.path location, eg for applets. file = new File(System.getProperty("java.library.path"), sourcePath); if (file.exists()) { System.load(file.getAbsolutePath()); return; } throw new GdxRuntimeException(ex); } /** @return null if the file was extracted and loaded. */ private Throwable loadFile(String sourcePath, String sourceCrc, File extractedFile) { try { System.load(extractFile(sourcePath, sourceCrc, extractedFile).getAbsolutePath()); return null; } catch (Throwable ex) { ex.printStackTrace(); return ex; } } }