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 org.apache.hadoop.chukwa.hicc; import java.io.BufferedReader; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.URISyntaxException; import java.net.URL; import java.net.URLConnection; import java.util.ArrayList; import java.util.Enumeration; import java.util.HashSet; import java.util.List; import java.util.Set; import java.util.jar.JarEntry; import java.util.jar.JarFile; import org.apache.hadoop.chukwa.conf.ChukwaConfiguration; import org.apache.hadoop.chukwa.util.DaemonWatcher; import org.apache.hadoop.chukwa.util.ExceptionUtil; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FSDataInputStream; import org.apache.hadoop.fs.FSDataOutputStream; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.hdfs.MiniDFSCluster; import org.json.JSONObject; import org.mortbay.jetty.Server; import org.mortbay.jetty.handler.ContextHandler; import org.mortbay.xml.XmlConfiguration; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class HiccWebServer { private static Log log = LogFactory.getLog(HiccWebServer.class); private static URL serverConf = null; private Server server = null; private String chukwaHdfs; private String hiccData; public static ChukwaConfiguration chukwaConf = new ChukwaConfiguration(); public static Configuration config = new Configuration(); public static FileSystem fs = null; private static HiccWebServer instance = null; protected HiccWebServer() { } // public HiccWebServer(Configuration conf) { // config = conf; // } // public static HiccWebServer getInstance() { if (instance == null) { config = new Configuration(); instance = new HiccWebServer(); } return instance; } public void start() { try { if (fs == null) { fs = FileSystem.get(config); chukwaHdfs = config.get("fs.default.name") + File.separator + chukwaConf.get("chukwa.data.dir"); hiccData = chukwaHdfs + File.separator + "hicc"; DaemonWatcher.createInstance("hicc"); serverConf = HiccWebServer.class.getResource("/WEB-INF/jetty.xml"); if (serverConf == null) { log.error("Unable to locate jetty-web.xml."); DaemonWatcher.bailout(-1); } instance = this; setupDefaultData(); run(); } } catch (Exception e) { log.error("HDFS unavailable, check configuration in chukwa-env.sh."); System.exit(-1); } } public static Configuration getConfig() { return config; } public static FileSystem getFileSystem() { return fs; } public List<String> getResourceListing(String path) throws URISyntaxException, IOException { ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader(); URL dirURL = contextClassLoader.getResource(path); if (dirURL == null) { dirURL = contextClassLoader.getResource(path); } if (dirURL.getProtocol().equals("jar")) { /* A JAR path */ String jarPath = dirURL.getPath().substring(5, dirURL.getPath().indexOf("!")); //strip out only the JAR file JarFile jar = new JarFile(jarPath); Enumeration<JarEntry> entries = jar.entries(); //gives ALL entries in jar List<String> result = new ArrayList<String>(); //avoid duplicates in case it is a subdirectory while (entries.hasMoreElements()) { String name = entries.nextElement().getName(); if (name.startsWith(path)) { //filter according to the path String entry = name.substring(path.length()); int checkSubdir = entry.indexOf("/"); if (checkSubdir == 0 && entry.length() > 1) { // if it is a subdirectory, we just return the directory name result.add(name); } } } return result; } throw new UnsupportedOperationException("Cannot list files for URL " + dirURL); } public void populateDir(List<String> files, Path path) { ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader(); for (String source : files) { String name = source.substring(source.indexOf(File.separator)); Path dest = new Path(path.toString() + File.separator + name); InputStream is = contextClassLoader.getResourceAsStream(source); StringBuilder sb = new StringBuilder(); String line = null; try { BufferedReader reader = new BufferedReader(new InputStreamReader(is)); while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } FSDataOutputStream out = fs.create(dest); out.write(sb.toString().getBytes()); out.close(); } catch (IOException e) { log.error("Error writing file: " + dest.toString()); } } } public void setupDefaultData() { Path hiccPath = new Path(hiccData); try { fs = FileSystem.get(config); if (!fs.exists(hiccPath)) { log.info("Initializing HICC Datastore."); // Create chukwa directory if (!fs.exists(new Path(chukwaHdfs))) { fs.mkdirs(new Path(chukwaHdfs)); } // Create hicc directory fs.mkdirs(hiccPath); // Populate widgets repository StringBuffer hiccWidgets = new StringBuffer(); hiccWidgets.append(hiccData); hiccWidgets.append(File.separator); hiccWidgets.append("widgets"); Path widgetsPath = new Path(hiccWidgets.toString()); fs.mkdirs(widgetsPath); List<String> widgets = getResourceListing("descriptors"); populateDir(widgets, widgetsPath); // Create views directory StringBuffer hiccViews = new StringBuffer(); hiccViews.append(hiccData); hiccViews.append(File.separator); hiccViews.append("views"); fs.mkdirs(new Path(hiccViews.toString())); // Create users repository StringBuffer hiccUsers = new StringBuffer(); hiccUsers.append(hiccViews); hiccUsers.append(File.separator); hiccUsers.append("users"); fs.mkdirs(new Path(hiccUsers.toString())); // Populate public repository StringBuffer hiccPublic = new StringBuffer(); hiccPublic.append(hiccViews); hiccPublic.append(File.separator); hiccPublic.append("public"); Path viewsPath = new Path(hiccPublic.toString()); fs.mkdirs(viewsPath); List<String> views = getResourceListing("views"); populateDir(views, viewsPath); log.info("HICC Datastore initialization completed."); } } catch (Exception ex) { log.error(ExceptionUtil.getStackTrace(ex)); } } public void run() { server = new Server(); XmlConfiguration configuration; try { configuration = new XmlConfiguration(serverConf); configuration.configure(server); server.start(); } catch (Exception e) { log.error(ExceptionUtil.getStackTrace(e)); } } public void shutdown() { try { server.stop(); DaemonWatcher.bailout(0); } catch (Exception e) { log.error(ExceptionUtil.getStackTrace(e)); } } public static void main(String[] args) { HiccWebServer hicc = HiccWebServer.getInstance(); hicc.start(); } }