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 io.dstream.tez.utils; import java.io.BufferedInputStream; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.lang.reflect.Method; import java.net.URL; import java.net.URLClassLoader; import java.util.ArrayList; import java.util.List; import java.util.UUID; import java.util.jar.Attributes; import java.util.jar.JarEntry; import java.util.jar.JarOutputStream; import java.util.jar.Manifest; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import com.google.common.base.Preconditions; /** * Utility class which contains methods related to generating JAR file * and/or byte stream from passed directory. * Currently used as a dev feature allowing auto-generation of the JAR filr from * local dev workspace when submitting Tez jobs directly from the IDE. */ public class ClassPathUtils { private final static Log logger = LogFactory.getLog(ClassPathUtils.class); /** * * @param resource */ public static void addResourceToClassPath(File resource) { try { Preconditions.checkState(resource != null && resource.exists(), "'resource' must not be null and it must exist: " + resource); URLClassLoader cl = (URLClassLoader) Thread.currentThread().getContextClassLoader(); Method addUrlMethod = URLClassLoader.class.getDeclaredMethod("addURL", URL.class); addUrlMethod.setAccessible(true); addUrlMethod.invoke(cl, resource.toURI().toURL()); } catch (Exception e) { throw new IllegalStateException(e); } } /** * Will create a JAR file from base dir * * @param sourceDir * @param jarName * @return */ public static File toJar(File sourceDir, String jarName) { if (!sourceDir.isAbsolute()) { throw new IllegalArgumentException("Source must be expressed through absolute path"); } Manifest manifest = new Manifest(); manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0"); File jarFile = new File(jarName); try { JarOutputStream target = new JarOutputStream(new FileOutputStream(jarFile), manifest); add(sourceDir, sourceDir.getAbsolutePath().length(), target); target.close(); } catch (Exception e) { throw new IllegalStateException( "Failed to create JAR file '" + jarName + "' from " + sourceDir.getAbsolutePath(), e); } return jarFile; } /** * * @param applicationName * @return */ public static String generateJarFileName(String applicationName) { StringBuffer nameBuffer = new StringBuffer(); nameBuffer.append(applicationName); nameBuffer.append("_"); nameBuffer.append(UUID.randomUUID().toString()); nameBuffer.append(".jar"); return nameBuffer.toString(); } /** * * @param source * @param lengthOfOriginalPath * @param target * @throws IOException */ private static void add(File source, int lengthOfOriginalPath, JarOutputStream target) throws IOException { BufferedInputStream in = null; try { String path = source.getAbsolutePath(); path = path.substring(lengthOfOriginalPath); if (source.isDirectory()) { String name = path.replace("\\", "/"); if (!name.isEmpty()) { if (!name.endsWith("/")) { name += "/"; } JarEntry entry = new JarEntry(name.substring(1)); // avoiding absolute path warning target.putNextEntry(entry); target.closeEntry(); } for (File nestedFile : source.listFiles()) { add(nestedFile, lengthOfOriginalPath, target); } return; } JarEntry entry = new JarEntry(path.replace("\\", "/").substring(1)); // avoiding absolute path warning entry.setTime(source.lastModified()); try { target.putNextEntry(entry); in = new BufferedInputStream(new FileInputStream(source)); byte[] buffer = new byte[1024]; while (true) { int count = in.read(buffer); if (count == -1) { break; } target.write(buffer, 0, count); } target.closeEntry(); } catch (Exception e) { String message = e.getMessage(); if (message != null) { if (!message.toLowerCase().contains("duplicate")) { throw new IllegalStateException(e); } logger.warn(message); } else { throw new IllegalStateException(e); } } } finally { if (in != null) in.close(); } } /** * * @param exclusionFile * @return */ public static String[] initClasspathExclusions(String exclusionFile) { String[] classpathExclusions = null; try { InputStream excInputStream = Thread.currentThread().getContextClassLoader() .getResourceAsStream(exclusionFile); if (excInputStream != null) { List<String> exclusionPatterns = new ArrayList<String>(); BufferedReader reader = new BufferedReader(new InputStreamReader(excInputStream)); String line; while ((line = reader.readLine()) != null) { exclusionPatterns.add(line.trim()); } classpathExclusions = exclusionPatterns.toArray(new String[] {}); reader.close(); } } catch (Exception e) { logger.warn("Failed to build the list of classpath exclusion. ", e); } return classpathExclusions; } }