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