[Processing] Watch Data Folder for Changed / Newly Created Files

Watch_Data_Directory_For_Changes.pde

import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY;
import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;
import static java.nio.file.StandardWatchEventKinds.OVERFLOW;

import java.io.IOException;
import java.nio.file.FileSystem;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.WatchEvent;
import java.nio.file.WatchEvent.Kind;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;

void setup(){
  thread("watchDataPath");
}

void draw(){}

void fileChanged(String filename){
  println("File Changed: " + filename);
  // Do something here
}

void fileCreated(String filename){
  println("File Created: " + filename);
  // Do something here
}

/*
 * Watches the data directory for newly created and modified files
 * Make sure the data directory exists.
 * It may take a few seconds until we get notified of changes here...
 */
  public void watchDataPath() {
    Path path = Paths.get(dataPath(""));
    try {
      // Check if path is a folder
      Boolean isFolder = (Boolean) Files.getAttribute(path,
          "basic:isDirectory", NOFOLLOW_LINKS);
      if (!isFolder) {
        throw new IllegalArgumentException("Path: " + path + " is not a folder");
      }
    } catch (IOException ioe) {
      ioe.printStackTrace(); // Folder does not exist
    }
    System.out.println("Watching folder: " + path);
    FileSystem fs = path.getFileSystem (); // We obtain the file system of the Path
    // We create the new WatchService
    try{
      WatchService service = fs.newWatchService();      
      // We register the path to the service
      path.register(service, ENTRY_CREATE); // We watch for new files
      path.register(service, ENTRY_MODIFY); // and modified files
      
      // Start the infinite polling loop
      WatchKey key = null;
      while(true) {
        key = service.take();
        
        // Dequeueing events
        Kind<?> kind = null;
        for(WatchEvent<?> watchEvent : key.pollEvents()) {
          // Get the type of the event
          kind = watchEvent.kind();
          if (OVERFLOW == kind) {
            continue; //loop
          } else if (ENTRY_CREATE == kind) {
            Path newPath = ((WatchEvent<Path>) watchEvent).context(); // A new Path was created 
            fileCreated(newPath.toString());
          } else if (ENTRY_MODIFY == kind) {
            Path modifiedPath = ((WatchEvent<Path>) watchEvent).context(); // File / Folder modified
            fileChanged(modifiedPath.toString());
          }
        }
        
        if(!key.reset()) {
          break; //loop
        }
      }
      
    }catch(Exception e) {e.printStackTrace();}
  }
  
  // tags: Processing, P5, File, Files, Folder, Directory, Change, Changed, Create, Created, Modified, Edited, File System, Watch