Java tutorial
/** * 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. See accompanying LICENSE file. */ package org.apache.hadoop.util; import com.google.common.base.Preconditions; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.URL; import java.net.URLDecoder; import java.text.MessageFormat; import java.util.Enumeration; import java.util.jar.JarFile; import java.util.jar.JarOutputStream; import java.util.jar.Manifest; import java.util.zip.ZipEntry; import java.util.zip.ZipOutputStream; import org.apache.hadoop.test.GenericTestUtils; /** * Finds the Jar for a class. If the class is in a directory in the * classpath, it creates a Jar on the fly with the contents of the directory * and returns the path to that Jar. If a Jar is created, it is created in * the system temporary directory. */ public class JarFinder { private static void copyToZipStream(File file, ZipEntry entry, ZipOutputStream zos) throws IOException { InputStream is = new FileInputStream(file); try { zos.putNextEntry(entry); byte[] arr = new byte[4096]; int read = is.read(arr); while (read > -1) { zos.write(arr, 0, read); read = is.read(arr); } } finally { try { is.close(); } finally { zos.closeEntry(); } } } public static void jarDir(File dir, String relativePath, ZipOutputStream zos) throws IOException { Preconditions.checkNotNull(relativePath, "relativePath"); Preconditions.checkNotNull(zos, "zos"); // by JAR spec, if there is a manifest, it must be the first entry in the // ZIP. File manifestFile = new File(dir, JarFile.MANIFEST_NAME); ZipEntry manifestEntry = new ZipEntry(JarFile.MANIFEST_NAME); if (!manifestFile.exists()) { zos.putNextEntry(manifestEntry); new Manifest().write(new BufferedOutputStream(zos)); zos.closeEntry(); } else { copyToZipStream(manifestFile, manifestEntry, zos); } zos.closeEntry(); zipDir(dir, relativePath, zos, true); zos.close(); } private static void zipDir(File dir, String relativePath, ZipOutputStream zos, boolean start) throws IOException { String[] dirList = dir.list(); for (String aDirList : dirList) { File f = new File(dir, aDirList); if (!f.isHidden()) { if (f.isDirectory()) { if (!start) { ZipEntry dirEntry = new ZipEntry(relativePath + f.getName() + "/"); zos.putNextEntry(dirEntry); zos.closeEntry(); } String filePath = f.getPath(); File file = new File(filePath); zipDir(file, relativePath + f.getName() + "/", zos, false); } else { String path = relativePath + f.getName(); if (!path.equals(JarFile.MANIFEST_NAME)) { ZipEntry anEntry = new ZipEntry(path); copyToZipStream(f, anEntry, zos); } } } } } private static void createJar(File dir, File jarFile) throws IOException { Preconditions.checkNotNull(dir, "dir"); Preconditions.checkNotNull(jarFile, "jarFile"); File jarDir = jarFile.getParentFile(); if (!jarDir.exists()) { if (!jarDir.mkdirs()) { throw new IOException(MessageFormat.format("could not create dir [{0}]", jarDir)); } } JarOutputStream zos = new JarOutputStream(new FileOutputStream(jarFile)); jarDir(dir, "", zos); } /** * Returns the full path to the Jar containing the class. It always return a * JAR. * * @param klass class. * * @return path to the Jar containing the class. */ public static String getJar(Class klass) { Preconditions.checkNotNull(klass, "klass"); ClassLoader loader = klass.getClassLoader(); if (loader != null) { String class_file = klass.getName().replaceAll("\\.", "/") + ".class"; try { for (Enumeration itr = loader.getResources(class_file); itr.hasMoreElements();) { URL url = (URL) itr.nextElement(); String path = url.getPath(); if (path.startsWith("file:")) { path = path.substring("file:".length()); } path = URLDecoder.decode(path, "UTF-8"); if ("jar".equals(url.getProtocol())) { path = URLDecoder.decode(path, "UTF-8"); return path.replaceAll("!.*$", ""); } else if ("file".equals(url.getProtocol())) { String klassName = klass.getName(); klassName = klassName.replace(".", "/") + ".class"; path = path.substring(0, path.length() - klassName.length()); File baseDir = new File(path); File testDir = GenericTestUtils.getTestDir(); testDir = testDir.getAbsoluteFile(); if (!testDir.exists()) { testDir.mkdirs(); } File tempJar = File.createTempFile("hadoop-", "", testDir); tempJar = new File(tempJar.getAbsolutePath() + ".jar"); createJar(baseDir, tempJar); tempJar.deleteOnExit(); return tempJar.getAbsolutePath(); } } } catch (IOException e) { throw new RuntimeException(e); } } return null; } public static File makeClassLoaderTestJar(Class<?> target, File rootDir, String jarName, int buffSize, String... clsNames) throws IOException { File jarFile = new File(rootDir, jarName); JarOutputStream jstream = new JarOutputStream(new FileOutputStream(jarFile)); for (String clsName : clsNames) { String name = clsName.replace('.', '/') + ".class"; InputStream entryInputStream = target.getResourceAsStream("/" + name); ZipEntry entry = new ZipEntry(name); jstream.putNextEntry(entry); BufferedInputStream bufInputStream = new BufferedInputStream(entryInputStream, buffSize); int count; byte[] data = new byte[buffSize]; while ((count = bufInputStream.read(data, 0, buffSize)) != -1) { jstream.write(data, 0, count); } jstream.closeEntry(); } jstream.close(); return jarFile; } }