bundles/org.simantics.fileimport/src/org/simantics/fileimport/dropins/FileImportDropins.java

   1 package org.simantics.fileimport.dropins;\r
   2 \r
   3 import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;\r
   4 import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;\r
   5 import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY;\r
   6 import static java.nio.file.StandardWatchEventKinds.OVERFLOW;\r
   7 \r
   8 import java.io.FileNotFoundException;\r
   9 import java.io.IOException;\r
  10 import java.io.RandomAccessFile;\r
  11 import java.nio.file.FileSystem;\r
  12 import java.nio.file.FileSystemException;\r
  13 import java.nio.file.FileVisitResult;\r
  14 import java.nio.file.Files;\r
  15 import java.nio.file.Path;\r
  16 import java.nio.file.SimpleFileVisitor;\r
  17 import java.nio.file.WatchEvent;\r
  18 import java.nio.file.WatchEvent.Kind;\r
  19 import java.nio.file.WatchKey;\r
  20 import java.nio.file.WatchService;\r
  21 import java.nio.file.attribute.BasicFileAttributes;\r
  22 import java.util.HashMap;\r
  23 import java.util.Map;\r
  24 import java.util.Optional;\r
  25 import java.util.concurrent.atomic.AtomicBoolean;\r
  26 \r
  27 import org.simantics.fileimport.Activator;\r
  28 import org.simantics.fileimport.FileImportService;\r
  29 \r
  30 /**\r
  31  * Directory watcher based on {@link java.nio.file.WatchService} which will listen to file changes inside the dropins directory\r
  32  * ~/workspace/.metadata/plugins/org.simantics.fileimport/dropins\r
  33  * \r
  34  * @author Jani Simomaa\r
  35  *\r
  36  */\r
  37 public class FileImportDropins {\r
  38     \r
  39     private static Thread watcherThread = null;\r
  40     private static DropinsFolderWatcher watcher = null;\r
  41 \r
  42     /**\r
  43      * Start watching the dropins folder which are located in\r
  44      * ~/workspace/.metadata/plugins/org.simantics.fileimport/dropins\r
  45      */\r
  46     public static void watchDropinsFolder() {\r
  47         if (watcher == null && watcherThread == null) {\r
  48             try {\r
  49                 watcher = new DropinsFolderWatcher(Activator.getDropinsFolder());\r
  50                 watcherThread = new Thread(watcher, "Simantics Dropins Folder watcher thread");\r
  51                 watcherThread.setDaemon(true);\r
  52                 watcherThread.start();\r
  53             } catch (IOException e) {\r
  54                 e.printStackTrace();\r
  55             }\r
  56         }\r
  57     }\r
  58     \r
  59     /**\r
  60      * Stop watching the dropins folder\r
  61      */\r
  62     public static void unwatchDropinsFolder() {\r
  63         if (watcher == null)\r
  64             return;\r
  65         watcher.stop();\r
  66         try {\r
  67             watcherThread.join(500);\r
  68             if (watcherThread.isAlive())\r
  69                 watcherThread.interrupt();\r
  70         } catch (InterruptedException e) {\r
  71             e.printStackTrace();\r
  72         }\r
  73         watcherThread = null;\r
  74         watcher = null;\r
  75     }\r
  76     \r
  77     private static class DropinsFolderWatcher implements Runnable {\r
  78 \r
  79         private final Path dropinsFolder;\r
  80         private final WatchService ws;\r
  81         private final AtomicBoolean stopped = new AtomicBoolean(true);\r
  82         \r
  83         private final Map<WatchKey, Path> keys = new HashMap<>();\r
  84         \r
  85         public DropinsFolderWatcher(Path dropinsFolder) throws IOException {\r
  86             this.dropinsFolder = dropinsFolder;\r
  87             FileSystem fs = dropinsFolder.getFileSystem();\r
  88             this.ws = fs.newWatchService();\r
  89             registerAll(this.dropinsFolder);\r
  90         }\r
  91         \r
  92         private static void syncPath(Path f) throws IOException {\r
  93             // Does not seem to need 's' according to unit test in Windows\r
  94             boolean synced = false;\r
  95             int count = 0;\r
  96             while (!synced) {\r
  97                 try (RandomAccessFile raf = new RandomAccessFile(f.toFile(), "rw")) {\r
  98                     raf.getFD().sync();\r
  99                     synced = true;\r
 100                 } catch (IOException e) {\r
 101                     if (count == 3) {\r
 102                         throw e;\r
 103                     } else {\r
 104                         try {\r
 105                             Thread.sleep(50);\r
 106                         } catch (InterruptedException e1) {\r
 107                             e1.printStackTrace();\r
 108                         }\r
 109                         count++;\r
 110                     }\r
 111                 }\r
 112             }\r
 113         }\r
 114         \r
 115         @Override\r
 116         public void run() {\r
 117             stopped.set(false);\r
 118 \r
 119             while (!stopped.get()) {\r
 120                 try {\r
 121                     WatchKey key = ws.take();\r
 122                     for (WatchEvent<?> watchEvent : key.pollEvents()) {\r
 123                         if (OVERFLOW == watchEvent.kind())\r
 124                             continue; // loop\r
 125                         \r
 126                         @SuppressWarnings("unchecked")\r
 127                         WatchEvent<Path> pathEvent = (WatchEvent<Path>) watchEvent;\r
 128                         Kind<Path> kind = pathEvent.kind();\r
 129                         \r
 130                         Path parent = keys.get(key);\r
 131                         Path newPath = parent.resolve(pathEvent.context());\r
 132                         if (FileImportService.DB_FILE.equals(newPath.getFileName().toString()))\r
 133                             continue;\r
 134                         if (ENTRY_CREATE == kind) {\r
 135                             System.out.println("New path created: " + newPath);\r
 136                             int current = 0;\r
 137                             \r
 138                             while (!Files.isWritable(newPath) && current <= 10) {\r
 139                                 System.out.println("Sleeping for file import (current=" + current +")");\r
 140                                 Thread.sleep(200);\r
 141                                 current++;\r
 142                             }\r
 143                             \r
 144                             FileImportService.performFileImport(newPath, Optional.of(t -> {\r
 145                                 if ((t instanceof FileSystemException) || (t instanceof FileNotFoundException)) {\r
 146                                     try {\r
 147                                         syncPath(newPath);\r
 148                                     } catch (IOException e) {\r
 149                                         e.printStackTrace();\r
 150                                     }\r
 151                                     FileImportService.performFileImport(newPath, Optional.empty());\r
 152                                 } else {\r
 153                                     t.printStackTrace();\r
 154                                 }\r
 155                             }));\r
 156                             register(newPath);\r
 157                             \r
 158                         } else if (ENTRY_MODIFY == kind) {\r
 159                             System.out.println("New path modified: " + newPath);\r
 160                         } else if (ENTRY_DELETE == kind) {\r
 161                             System.out.println("New path deleted: " + newPath);\r
 162                             FileImportService.removeResourceForFile(newPath.toAbsolutePath(), Optional.empty());\r
 163                         }\r
 164                     }\r
 165                     if (!key.reset()) {\r
 166                         keys.remove(key);\r
 167 //                        break; // loop\r
 168                     }\r
 169                 } catch (InterruptedException e) {\r
 170                     if (!stopped.get())\r
 171                         e.printStackTrace();\r
 172                 } catch (Throwable t) {\r
 173                     t.printStackTrace();\r
 174                 }\r
 175             }\r
 176         }\r
 177         \r
 178         public void stop() {\r
 179             stopped.set(true);\r
 180         }\r
 181         \r
 182         private void registerAll(Path path) throws IOException {\r
 183             Files.walkFileTree(path, new SimpleFileVisitor<Path>() {\r
 184                 \r
 185                 @Override\r
 186                 public FileVisitResult preVisitDirectory(Path file, BasicFileAttributes attrs) throws IOException {\r
 187                     register(file);\r
 188                     return FileVisitResult.CONTINUE;\r
 189                 }\r
 190             });\r
 191         }\r
 192 \r
 193         private void register(Path path) throws IOException {\r
 194             if (Files.isDirectory(path)) {\r
 195                 WatchKey key = path.toAbsolutePath().register(ws, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);\r
 196                 keys.put(key, path);\r
 197             }\r
 198         }\r
 199     }\r
 200 }\r