Polling from a network directory

Question

I have been working on the following project, some background:

I am an intern currently developing a new search system for my organization. The current setup is microsoft sharepoint 2013 in which the users upload files etc.. and on the other hand is the system I am developing which indexes all data being uploaded to apache SOLR.

I have been succesfull in mapping the sharepoint content repository to a network drive, and I can manually start my program to start indexing the conent of this network drive to SOLR using the Solrj api.

The problem I am facing however is that I am unable to poll events from this network drive. In my test build which ran local I used a watcher service to launch code (reindex documents, delete indexes) on file create, file modify and file delete.

This does not work unfortunantly with a url pointing to a network drive :(.

So the big question: Is there any API / library available for polling events from network drives?

Any help would be extemely appreciated !

Answer 1

So I fnally figured this one out, tried looking at .net's variant of the watcher service (system.io.filesystemwatcher) and i was having the same problem. I finally got it working by using java.io.FileAlterationMonitor / observer.

Code:

public class UNCWatcher {
// A hardcoded path to a folder you are monitoring .
public static final String FOLDER =
        "A:\\Department";

public static void main(String[] args) throws Exception {
    // The monitor will perform polling on the folder every 5 seconds
    final long pollingInterval = 5 * 1000;


    File folder = new File(FOLDER);

    if (!folder.exists()) {
        // Test to see if monitored folder exists
        throw new RuntimeException("Directory not found: " + FOLDER);
    }

    FileAlterationObserver observer = new FileAlterationObserver(folder);
    FileAlterationMonitor monitor =
            new FileAlterationMonitor(pollingInterval);
    FileAlterationListener listener = new FileAlterationListenerAdaptor() {
        // Is triggered when a file is created in the monitored folder
        @Override
        public void onFileCreate(File file) {
            try {
                // "file" is the reference to the newly created file
                System.out.println("File created: "
                        + file.getCanonicalPath());



                if(file.getName().endsWith(".docx")){
                    System.out.println("Uploaded resource is of type docx, preparing solr for indexing.");
                }


            } catch (IOException e) {
                e.printStackTrace(System.err);
            }
        }

        // Is triggered when a file is deleted from the monitored folder
        @Override
        public void onFileDelete(File file) {
            try {
                // "file" is the reference to the removed file
                System.out.println("File removed: "
                        + file.getCanonicalPath());
                // "file" does not exists anymore in the location
                System.out.println("File still exists in location: "
                        + file.exists());
            } catch (IOException e) {
                e.printStackTrace(System.err);
            }
        }
    };

    observer.addListener(listener);
    monitor.addObserver(observer);
    System.out.println("Starting monitor service");
    monitor.start();
  }
}