Java tutorial
/* * Copyright (c) 2013 Technische Universitat Wien (TUW), Distributed Systems Group. http://dsg.tuwien.ac.at * * This work was partially supported by the European Commission in terms of the CELAR FP7 project (FP7-ICT-2011-8 #317790), http://www.celarcloud.eu/ * * 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 at.ac.tuwien.dsg.cloud.salsa.engine.utils; import java.io.File; import java.io.IOException; import java.io.BufferedReader; import java.io.InputStreamReader; import java.lang.management.ManagementFactory; import java.net.Inet4Address; import java.net.InetAddress; import java.net.URL; import java.net.UnknownHostException; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import java.util.logging.Level; import javax.management.AttributeNotFoundException; import javax.management.InstanceNotFoundException; import javax.management.MBeanException; import javax.management.MBeanServer; import javax.management.MalformedObjectNameException; import javax.management.ObjectName; import javax.management.Query; import javax.management.ReflectionException; import org.apache.commons.io.FileUtils; import org.slf4j.Logger; public class SystemFunctions { private final static File envFileGlobal = new File("/etc/environment"); private static final Logger logger = EngineLogger.logger; static private String localIP = null; public static String getEth0IPAddress() { if (localIP != null) { logger.debug("Return local IP address:" + localIP); return localIP; } // copy the getEth0IPv4 to /tmp and execute it, return the value URL inputUrl = SystemFunctions.class.getResource("/scripts/getEth0IPv4.sh"); EngineLogger.logger.debug("Search script: " + inputUrl); File dest = new File("/tmp/getEth0IPv4.sh"); try { FileUtils.copyURLToFile(inputUrl, dest); } catch (IOException ex) { EngineLogger.logger .error("Cannot create template script file from: " + inputUrl + " to: " + dest.getPath()); } localIP = executeCommandGetOutput("/bin/bash /tmp/getEth0IPv4.sh", "/tmp", null); localIP = localIP.trim(); if (isIPv4Address(localIP)) { logger.debug("The {} is IPv4 !", localIP); return localIP; } else { logger.debug("Cannot get IPv4, the command return: {}", localIP); localIP = null; return "localhost"; } } public static boolean isIPv4Address(String address) { if (address.isEmpty()) { return false; } try { Object res = InetAddress.getByName(address); return (res.getClass().equals(Inet4Address.class)); } catch (final UnknownHostException ex) { logger.error("Cannot get the host IP address. The captured address is: {}. Error: {}", address, ex.getMessage()); return false; } } public static void executeCommandSimple(String cmd, String workingDir) { logger.debug("Running command: {} in folder: {}", cmd, workingDir); Process p; try { String newCmd = "cd " + workingDir + " && " + cmd; logger.debug("The whole command to execute: {}", newCmd); p = Runtime.getRuntime().exec(newCmd); p.waitFor(); } catch (IOException | InterruptedException ex) { logger.error("Error when run command: {}", cmd, ex); } } public static int executeCommandGetReturnCode(String cmd, String workingDir, String executeFrom) { if (workingDir == null) { workingDir = "/tmp"; } logger.debug("Execute command: " + cmd + ". Working dir: " + workingDir); try { String[] splitStr = cmd.split("\\s+"); ProcessBuilder pb = new ProcessBuilder(splitStr); pb.directory(new File(workingDir)); pb = pb.redirectErrorStream(true); // this is important to redirect the error stream to output stream, prevent blocking with long output Map<String, String> env = pb.environment(); String path = env.get("PATH"); path = path + File.pathSeparator + "/usr/bin:/usr/sbin"; logger.debug("PATH to execute command: " + pb.environment().get("PATH")); env.put("PATH", path); Process p = pb.start(); BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream())); String line; while ((line = reader.readLine()) != null) { logger.debug(line); } p.waitFor(); int returnCode = p.exitValue(); logger.debug("Execute command done: " + cmd + ". Get return code: " + returnCode); return returnCode; } catch (InterruptedException | IOException e1) { logger.error("Error when execute command. Error: " + e1); } return -1; } /** * Run a command and wait * * @param cmd The command to run * @param workingDir The folder where the command is run * @param executeFrom For logging message to the center of where to execute the command. * @return */ public static String executeCommandGetOutput(String cmd, String workingDir, String executeFrom) { logger.debug("Execute command: " + cmd); if (workingDir == null) { workingDir = "/tmp"; } try { String[] splitStr = cmd.split("\\s+"); ProcessBuilder pb = new ProcessBuilder(splitStr); pb.directory(new File(workingDir)); pb = pb.redirectErrorStream(true); // this is important to redirect the error stream to output stream, prevent blocking with long output Map<String, String> env = pb.environment(); String path = env.get("PATH"); path = path + File.pathSeparator + "/usr/bin:/usr/sbin"; logger.debug("PATH to execute command: " + pb.environment().get("PATH")); env.put("PATH", path); Process p = pb.start(); BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream())); String line; StringBuffer output = new StringBuffer(); int lineCount = 0; while ((line = reader.readLine()) != null) { if (lineCount < 10) { // only get 10 lines to prevent the overflow output.append(line); } lineCount += 1; logger.debug(line); } if (lineCount >= 10) { logger.debug("... there are alot of more output here which is not shown ! ..."); } p.waitFor(); System.out.println("Execute Commang output: " + output.toString().trim()); if (p.exitValue() == 0) { logger.debug("Command exit 0, result: " + output.toString().trim()); return output.toString().trim(); } else { logger.debug("Command return non zero code: " + p.exitValue()); return null; } } catch (InterruptedException | IOException e1) { logger.error("Error when execute command. Error: " + e1); } return null; } /** * Run a command and wait * * @param cmd The command to run * @param workingDir The folder where the command is run * @param executeFrom For logging message to the center of where to execute the command. * @return */ public static Process executeCommandAndForget(String cmd, String workingDir, String executeFrom) { logger.debug("Execute command: " + cmd); if (workingDir == null) { workingDir = "/tmp"; } String[] splitStr = cmd.split("\\s+"); ProcessBuilder pb = new ProcessBuilder(splitStr); pb.directory(new File(workingDir)); pb = pb.redirectErrorStream(true); // this is important to redirect the error stream to output stream, prevent blocking with long output pb.redirectOutput(new File("/tmp/salsa.conductor.log")); Map<String, String> env = pb.environment(); String path = env.get("PATH"); path = path + File.pathSeparator + "/usr/bin:/usr/sbin"; logger.debug("PATH to execute command: " + pb.environment().get("PATH")); env.put("PATH", path); Process p; try { p = pb.start(); return p; } catch (IOException ex) { logger.debug("Cannot run the command: " + cmd); return null; } } public static List<String> getEndPoints() throws MalformedObjectNameException, NullPointerException, UnknownHostException, AttributeNotFoundException, InstanceNotFoundException, MBeanException, ReflectionException { MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); Set<ObjectName> objs = mbs.queryNames(new ObjectName("*:type=Connector,*"), Query.match(Query.attr("protocol"), Query.value("HTTP/1.1"))); String hostname = InetAddress.getLocalHost().getHostName(); InetAddress[] addresses = InetAddress.getAllByName(hostname); ArrayList<String> endPoints = new ArrayList<>(); for (Iterator<ObjectName> i = objs.iterator(); i.hasNext();) { ObjectName obj = i.next(); String scheme = mbs.getAttribute(obj, "scheme").toString(); String port = obj.getKeyProperty("port"); for (InetAddress addr : addresses) { String host = addr.getHostAddress(); String ep = scheme + "://" + host + ":" + port; endPoints.add(ep); } } return endPoints; } /** * This command try to get Port which the service is listening to. The port should be in the parameter -httpPort when running, or Tomcat port * * @return */ public static String getPort() { try { MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); Set<ObjectName> objs = mbs.queryNames(new ObjectName("*:type=Connector,*"), Query.match(Query.attr("protocol"), Query.value("HTTP/1.1"))); for (ObjectName obj : objs) { String port = obj.getKeyProperty("port"); return port; } } catch (MalformedObjectNameException e) { EngineLogger.logger .error("Cannot get listening port of salsa-engine service. return 8080 as default. Error: " + e.toString()); } EngineLogger.logger.error("Cannot find listening port of salsa-engine service. return 8080 as default"); return "8080"; } }