001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2008-2011 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    package org.sonar.api.utils.command;
021    
022    import java.io.BufferedReader;
023    import java.io.IOException;
024    import java.io.InputStream;
025    import java.io.InputStreamReader;
026    import java.util.concurrent.*;
027    
028    import org.apache.commons.io.IOUtils;
029    import org.slf4j.Logger;
030    import org.slf4j.LoggerFactory;
031    
032    /**
033     * Synchronously execute a native command line. It's much more limited than the Apache Commons Exec library.
034     * For example it does not allow to get process output, to run asynchronously or to automatically quote
035     * command-line arguments.
036     *
037     * @since 2.7
038     */
039    public final class CommandExecutor {
040    
041      private static final CommandExecutor INSTANCE = new CommandExecutor();
042    
043      private CommandExecutor() {
044      }
045    
046      public static CommandExecutor create() {
047        // stateless object, so a single singleton can be shared
048        return INSTANCE;
049      }
050    
051      public int execute(Command command, long timeoutMilliseconds) {
052        ExecutorService executorService = null;
053        Process process = null;
054        StreamGobbler outputGobbler = null;
055        StreamGobbler errorGobbler = null;
056        try {
057          LoggerFactory.getLogger(getClass()).debug("Executing command: " + command);
058          ProcessBuilder builder = new ProcessBuilder(command.toStrings());
059          if (command.getDirectory() != null) {
060            builder.directory(command.getDirectory());
061          }
062          process = builder.start();
063    
064          // consume and display the error and output streams
065          outputGobbler = new StreamGobbler(process.getInputStream());
066          errorGobbler = new StreamGobbler(process.getErrorStream());
067          outputGobbler.start();
068          errorGobbler.start();
069    
070          final Process finalProcess = process;
071          Callable<Integer> call = new Callable<Integer>() {
072            public Integer call() throws Exception {
073              return finalProcess.waitFor();
074            }
075          };
076    
077          executorService = Executors.newSingleThreadExecutor();
078          Future<Integer> ft = executorService.submit(call);
079          return ft.get(timeoutMilliseconds, TimeUnit.MILLISECONDS);
080    
081        } catch (TimeoutException te) {
082          process.destroy();
083          throw new CommandException(command, "Timeout exceeded: " + timeoutMilliseconds + " ms", te);
084    
085        } catch (Exception e) {
086          throw new CommandException(command, e);
087    
088        } finally {
089          waitUntilFinish(outputGobbler);
090          waitUntilFinish(errorGobbler);
091          closeStreams(process);
092    
093          if (executorService != null) {
094            executorService.shutdown();
095          }
096        }
097      }
098    
099      private void closeStreams(Process process) {
100        if (process != null) {
101          IOUtils.closeQuietly(process.getInputStream());
102          IOUtils.closeQuietly(process.getOutputStream());
103          IOUtils.closeQuietly(process.getErrorStream());
104        }
105      }
106    
107      private void waitUntilFinish(StreamGobbler thread) {
108        if (thread != null) {
109          try {
110            thread.join();
111          } catch (InterruptedException e) {
112            // ignore
113          }
114        }
115      }
116    
117      private static class StreamGobbler extends Thread {
118        InputStream is;
119    
120        StreamGobbler(InputStream is) {
121          super("ProcessStreamGobbler");
122          this.is = is;
123        }
124    
125        @Override
126        public void run() {
127          Logger logger = LoggerFactory.getLogger(CommandExecutor.class);
128          InputStreamReader isr = new InputStreamReader(is);
129          BufferedReader br = new BufferedReader(isr);
130          try {
131            String line;
132            while ((line = br.readLine()) != null) {
133              logger.info(line);
134            }
135          } catch (IOException ioe) {
136            logger.error("Error while reading stream", ioe);
137    
138          } finally {
139            IOUtils.closeQuietly(br);
140            IOUtils.closeQuietly(isr);
141          }
142        }
143      }
144    }