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 com.cloud.utils.script; import java.io.BufferedReader; import java.io.File; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.io.StringWriter; import java.net.URI; import java.net.URISyntaxException; import java.net.URL; import java.util.ArrayList; import java.util.List; import java.util.Properties; import java.util.concurrent.Callable; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.ScheduledFuture; import java.util.concurrent.TimeUnit; import org.apache.commons.io.IOUtils; import org.apache.log4j.Logger; import com.cloud.utils.PropertiesUtil; import com.cloud.utils.concurrency.NamedThreadFactory; import com.cloud.utils.script.OutputInterpreter.TimedOutLogger; public class Script implements Callable<String> { private static final Logger s_logger = Logger.getLogger(Script.class); private final Logger _logger; public static final String ERR_EXECUTE = "execute.error"; public static final String ERR_TIMEOUT = "timeout"; private int _defaultTimeout = 3600 * 1000; /* 1 hour */ private volatile boolean _isTimeOut = false; private boolean _passwordCommand = false; private static final ScheduledExecutorService s_executors = Executors.newScheduledThreadPool(10, new NamedThreadFactory("Script")); String _workDir; ArrayList<String> _command; long _timeout; Process _process; Thread _thread; public int getExitValue() { return _process.exitValue(); } public Script(String command, long timeout, Logger logger) { _command = new ArrayList<String>(); _command.add(command); _timeout = timeout; if (_timeout == 0) { /* always using default timeout 1 hour to avoid thread hang */ _timeout = _defaultTimeout; } _process = null; _logger = logger != null ? logger : s_logger; } public Script(boolean runWithSudo, String command, long timeout, Logger logger) { this(command, timeout, logger); if (runWithSudo) { _command.add(0, "sudo"); } } public Script(String command, Logger logger) { this(command, 0, logger); } public Script(String command) { this(command, 0, s_logger); } public Script(String command, long timeout) { this(command, timeout, s_logger); } public void add(String... params) { for (String param : params) { _command.add(param); } } public void add(String param) { _command.add(param); } public Script set(String name, String value) { _command.add(name); _command.add(value); return this; } public void setWorkDir(String workDir) { _workDir = workDir; } protected String buildCommandLine(String[] command) { StringBuilder builder = new StringBuilder(); boolean obscureParam = false; for (int i = 0; i < command.length; i++) { String cmd = command[i]; if (obscureParam) { builder.append("******").append(" "); obscureParam = false; } else { builder.append(command[i]).append(" "); } if ("-y".equals(cmd) || "-z".equals(cmd)) { obscureParam = true; _passwordCommand = true; } } return builder.toString(); } protected String buildCommandLine(List<String> command) { StringBuilder builder = new StringBuilder(); boolean obscureParam = false; for (String cmd : command) { if (obscureParam) { builder.append("******").append(" "); obscureParam = false; } else { builder.append(cmd).append(" "); } if ("-y".equals(cmd) || "-z".equals(cmd)) { obscureParam = true; _passwordCommand = true; } } return builder.toString(); } public long getTimeout() { return _timeout; } public String execute() { return execute(new OutputInterpreter.OutputLogger(_logger)); } @Override public String toString() { String[] command = _command.toArray(new String[_command.size()]); return buildCommandLine(command); } static String stackTraceAsString(Throwable throwable) { //TODO: a StringWriter is bit to heavy weight try (StringWriter out = new StringWriter(); PrintWriter writer = new PrintWriter(out);) { throwable.printStackTrace(writer); return out.toString(); } catch (IOException e) { return ""; } } public String execute(OutputInterpreter interpreter) { String[] command = _command.toArray(new String[_command.size()]); if (_logger.isDebugEnabled()) { _logger.debug("Executing: " + buildCommandLine(command)); } try { ProcessBuilder pb = new ProcessBuilder(command); pb.redirectErrorStream(true); if (_workDir != null) pb.directory(new File(_workDir)); _process = pb.start(); if (_process == null) { _logger.warn("Unable to execute: " + buildCommandLine(command)); return "Unable to execute the command: " + command[0]; } BufferedReader ir = new BufferedReader(new InputStreamReader(_process.getInputStream())); _thread = Thread.currentThread(); ScheduledFuture<String> future = null; if (_timeout > 0) { future = s_executors.schedule(this, _timeout, TimeUnit.MILLISECONDS); } Task task = null; if (interpreter != null && interpreter.drain()) { task = new Task(interpreter, ir); s_executors.execute(task); } while (true) { try { if (_process.waitFor() == 0) { _logger.debug("Execution is successful."); if (interpreter != null) { return interpreter.drain() ? task.getResult() : interpreter.interpret(ir); } else { // null return exitValue apparently return String.valueOf(_process.exitValue()); } } else { break; } } catch (InterruptedException e) { if (!_isTimeOut) { /* * This is not timeout, we are interrupted by others, * continue */ _logger.debug("We are interrupted but it's not a timeout, just continue"); continue; } TimedOutLogger log = new TimedOutLogger(_process); Task timedoutTask = new Task(log, ir); timedoutTask.run(); if (!_passwordCommand) { _logger.warn("Timed out: " + buildCommandLine(command) + ". Output is: " + timedoutTask.getResult()); } else { _logger.warn("Timed out: " + buildCommandLine(command)); } return ERR_TIMEOUT; } finally { if (future != null) { future.cancel(false); } Thread.interrupted(); } } _logger.debug("Exit value is " + _process.exitValue()); BufferedReader reader = new BufferedReader(new InputStreamReader(_process.getInputStream()), 128); String error; if (interpreter != null) { error = interpreter.processError(reader); } else { error = String.valueOf(_process.exitValue()); } if (_logger.isDebugEnabled()) { _logger.debug(error); } return error; } catch (SecurityException ex) { _logger.warn("Security Exception....not running as root?", ex); return stackTraceAsString(ex); } catch (Exception ex) { _logger.warn("Exception: " + buildCommandLine(command), ex); return stackTraceAsString(ex); } finally { if (_process != null) { IOUtils.closeQuietly(_process.getErrorStream()); IOUtils.closeQuietly(_process.getOutputStream()); IOUtils.closeQuietly(_process.getInputStream()); _process.destroy(); } } } @Override public String call() { try { _logger.trace("Checking exit value of process"); _process.exitValue(); _logger.trace("Script ran within the alloted time"); } catch (IllegalThreadStateException e) { _logger.warn("Interrupting script."); _isTimeOut = true; _thread.interrupt(); } return null; } public static class Task implements Runnable { OutputInterpreter interpreter; BufferedReader reader; String result; boolean done; public Task(OutputInterpreter interpreter, BufferedReader reader) { this.interpreter = interpreter; this.reader = reader; result = null; } @Override public void run() { synchronized (this) { done = false; try { result = interpreter.interpret(reader); } catch (IOException ex) { result = stackTraceAsString(ex); } catch (Exception ex) { result = stackTraceAsString(ex); } finally { done = true; notifyAll(); IOUtils.closeQuietly(reader); } } } public synchronized String getResult() throws InterruptedException { if (!done) { wait(); } return result; } } public static String findScript(String path, String script) { s_logger.debug("Looking for " + script + " in the classpath"); URL url = ClassLoader.getSystemResource(script); s_logger.debug("System resource: " + url); File file = null; if (url != null) { file = new File(url.getFile()); s_logger.debug("Absolute path = " + file.getAbsolutePath()); return file.getAbsolutePath(); } if (path == null) { s_logger.warn("No search path specified, unable to look for " + script); return null; } path = path.replace("/", File.separator); /** * Look in WEB-INF/classes of the webapp * URI workaround the URL encoding of url.getFile */ if (path.endsWith(File.separator)) { url = Script.class.getClassLoader().getResource(path + script); } else { url = Script.class.getClassLoader().getResource(path + File.separator + script); } s_logger.debug("Classpath resource: " + url); if (url != null) { try { file = new File(new URI(url.toString()).getPath()); s_logger.debug("Absolute path = " + file.getAbsolutePath()); return file.getAbsolutePath(); } catch (URISyntaxException e) { s_logger.warn("Unable to convert " + url.toString() + " to a URI"); } } if (path.endsWith(File.separator)) { path = path.substring(0, path.lastIndexOf(File.separator)); } if (path.startsWith(File.separator)) { // Path given was absolute so we assume the caller knows what they want. file = new File(path + File.separator + script); return file.exists() ? file.getAbsolutePath() : null; } s_logger.debug("Looking for " + script); String search = null; for (int i = 0; i < 3; i++) { if (i == 0) { String cp = Script.class.getResource(Script.class.getSimpleName() + ".class").toExternalForm(); int begin = cp.indexOf(File.separator); // work around with the inconsistency of java classpath and file separator on Windows 7 if (begin < 0) begin = cp.indexOf('/'); int endBang = cp.lastIndexOf("!"); int end = cp.lastIndexOf(File.separator, endBang); if (end < 0) end = cp.lastIndexOf('/', endBang); if (end < 0) cp = cp.substring(begin); else cp = cp.substring(begin, end); s_logger.debug("Current binaries reside at " + cp); search = cp; } else if (i == 1) { s_logger.debug("Searching in environment.properties"); try { final File propsFile = PropertiesUtil.findConfigFile("environment.properties"); if (propsFile == null) { s_logger.debug("environment.properties could not be opened"); } else { final Properties props = PropertiesUtil.loadFromFile(propsFile); search = props.getProperty("paths.script"); } } catch (IOException e) { s_logger.debug("environment.properties could not be opened"); continue; } s_logger.debug("environment.properties says scripts should be in " + search); } else { s_logger.debug("Searching in the current directory"); search = "."; } search += File.separatorChar + path + File.separator; do { search = search.substring(0, search.lastIndexOf(File.separator)); file = new File(search + File.separator + script); s_logger.debug("Looking for " + script + " in " + file.getAbsolutePath()); } while (!file.exists() && search.lastIndexOf(File.separator) != -1); if (file.exists()) { return file.getAbsolutePath(); } } search = System.getProperty("paths.script"); search += File.separatorChar + path + File.separator; do { search = search.substring(0, search.lastIndexOf(File.separator)); file = new File(search + File.separator + script); s_logger.debug("Looking for " + script + " in " + file.getAbsolutePath()); } while (!file.exists() && search.lastIndexOf(File.separator) != -1); if (file.exists()) { return file.getAbsolutePath(); } s_logger.warn("Unable to find script " + script); return null; } public static String runSimpleBashScript(String command) { return Script.runSimpleBashScript(command, 0); } public static String runSimpleBashScript(String command, int timeout) { Script s = new Script("/bin/bash", timeout); s.add("-c"); s.add(command); OutputInterpreter.OneLineParser parser = new OutputInterpreter.OneLineParser(); if (s.execute(parser) != null) return null; String result = parser.getLine(); if (result == null || result.trim().isEmpty()) return null; else return result.trim(); } public static int runSimpleBashScriptForExitValue(String command) { return runSimpleBashScriptForExitValue(command, 0); } public static int runSimpleBashScriptForExitValue(String command, int timeout) { Script s = new Script("/bin/bash", timeout); s.add("-c"); s.add(command); String result = s.execute(null); if (result == null || result.trim().isEmpty()) return -1; else { try { return Integer.parseInt(result.trim()); } catch (NumberFormatException e) { return -1; } } } }