Java tutorial
/** * Copyright (c) 2002-2006, Marc Prud'hommeaux <mwp1@cornell.edu> * All rights reserved. * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with * the distribution. * * Neither the name of JLine nor the names of its contributors * may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO * EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. */ /** * 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.hive.beeline; import jline.console.completer.StringsCompleter; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.io.File; import java.io.IOException; import java.io.FileInputStream; import java.net.JarURLConnection; import java.net.URL; import java.net.URLClassLoader; import java.net.URLConnection; import java.util.Arrays; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.ArrayList; import java.util.Set; import java.util.jar.JarEntry; import java.util.jar.JarFile; import java.util.Enumeration; import java.util.TreeSet; import java.util.zip.ZipInputStream; import java.util.zip.ZipEntry; /** * the completer is original provided in JLine 0.9.94 and is being removed in 2.12. Add the * previous implement for usage of the beeline. */ public class ClassNameCompleter extends StringsCompleter { private static final Log LOG = LogFactory.getLog(ClassNameCompleter.class.getName()); public final static String clazzFileNameExtension = ".class"; public final static String jarFileNameExtension = ".jar"; public ClassNameCompleter(String... candidates) { super(candidates); } public static String[] getClassNames() throws IOException { Set urls = new HashSet(); for (ClassLoader loader = Thread.currentThread().getContextClassLoader(); loader != null; loader = loader .getParent()) { if (!(loader instanceof URLClassLoader)) { continue; } urls.addAll(Arrays.asList(((URLClassLoader) loader).getURLs())); } // Now add the URL that holds java.lang.String. This is because // some JVMs do not report the core classes jar in the list of // class loaders. Class[] systemClasses = new Class[] { String.class, javax.swing.JFrame.class }; for (int i = 0; i < systemClasses.length; i++) { URL classURL = systemClasses[i] .getResource("/" + systemClasses[i].getName().replace('.', '/') + clazzFileNameExtension); if (classURL != null) { URLConnection uc = classURL.openConnection(); if (uc instanceof JarURLConnection) { urls.add(((JarURLConnection) uc).getJarFileURL()); } } } Set classes = new HashSet(); for (Iterator i = urls.iterator(); i.hasNext();) { URL url = (URL) i.next(); File file = new File(url.getFile()); if (file.isDirectory()) { Set files = getClassFiles(file.getAbsolutePath(), new HashSet(), file, new int[] { 200 }); classes.addAll(files); continue; } if ((file == null) || !file.isFile()) { continue; } JarFile jf = new JarFile(file); for (Enumeration e = jf.entries(); e.hasMoreElements();) { JarEntry entry = (JarEntry) e.nextElement(); if (entry == null) { continue; } String name = entry.getName(); if (isClazzFile(name)) { /* only use class file*/ classes.add(name); } else if (isJarFile(name)) { classes.addAll(getClassNamesFromJar(name)); } else { continue; } } } // now filter classes by changing "/" to "." and trimming the // trailing ".class" Set classNames = new TreeSet(); for (Iterator i = classes.iterator(); i.hasNext();) { String name = (String) i.next(); classNames.add(name.replace('/', '.').substring(0, name.length() - 6)); } return (String[]) classNames.toArray(new String[classNames.size()]); } private static Set getClassFiles(String root, Set holder, File directory, int[] maxDirectories) { // we have passed the maximum number of directories to scan if (maxDirectories[0]-- < 0) { return holder; } File[] files = directory.listFiles(); for (int i = 0; (files != null) && (i < files.length); i++) { String name = files[i].getAbsolutePath(); if (!(name.startsWith(root))) { continue; } else if (files[i].isDirectory()) { getClassFiles(root, holder, files[i], maxDirectories); } else if (files[i].getName().endsWith(clazzFileNameExtension)) { holder.add(files[i].getAbsolutePath().substring(root.length() + 1)); } } return holder; } /** * Get clazz names from a jar file path * @param path specifies the jar file's path * @return */ private static List<String> getClassNamesFromJar(String path) { List<String> classNames = new ArrayList<String>(); ZipInputStream zip = null; try { zip = new ZipInputStream(new FileInputStream(path)); ZipEntry entry = zip.getNextEntry(); while (entry != null) { if (!entry.isDirectory() && entry.getName().endsWith(clazzFileNameExtension)) { StringBuilder className = new StringBuilder(); for (String part : entry.getName().split("/")) { if (className.length() != 0) { className.append("."); } className.append(part); if (part.endsWith(clazzFileNameExtension)) { className.setLength(className.length() - clazzFileNameExtension.length()); } } classNames.add(className.toString()); } entry = zip.getNextEntry(); } } catch (IOException e) { LOG.error("Fail to parse the class name from the Jar file due to the exception:" + e); } finally { if (zip != null) { try { zip.close(); } catch (IOException e) { LOG.error("Fail to close the file due to the exception:" + e); } } } return classNames; } private static boolean isJarFile(String fileName) { return fileName.endsWith(jarFileNameExtension); } private static boolean isClazzFile(String clazzName) { return clazzName.endsWith(clazzFileNameExtension); } }