FileReader.java

package com.folion.core.service;

import java.io.IOException;
import java.nio.charset.CoderResult;
import java.nio.file.*;

public class FileReader {

    public void watch() throws IOException {
        WatchService watcher = FileSystems.getDefault().newWatchService();

        Path dir = Paths.get("/Users/programmer/folion.com");

        try {
            WatchKey key = dir.register(watcher,
                    StandardWatchEventKinds.ENTRY_CREATE,
                    StandardWatchEventKinds.ENTRY_DELETE,
                    StandardWatchEventKinds.ENTRY_MODIFY);
        } catch (IOException x) {
            System.err.println(x);
        }

        for (;;) {

            // wait for key to be signaled
            WatchKey key;
            try {
                key = watcher.take();
            } catch (InterruptedException x) {
                return;
            }

            for (WatchEvent<?> event: key.pollEvents()) {
                WatchEvent.Kind<?> kind = event.kind();

                // This key is registered only
                // for ENTRY_CREATE events,
                // but an OVERFLOW event can
                // occur regardless if events
                // are lost or discarded.
                if (kind == CoderResult.OVERFLOW) {
                    continue;
                }

                // The filename is the
                // context of the event.
                WatchEvent<Path> ev = (WatchEvent<Path>)event;
                Path filename = ev.context();

                Path child = dir.resolve(filename);
                // Verify that the new
                //  file is a text file.
//                try {
//                    // Resolve the filename against the directory.
//                    // If the filename is "test" and the directory is "foo",
//                    // the resolved name is "test/foo".
//                    Path child = dir.resolve(filename);
//
//                    if (!Files.probeContentType(child).equals("text/plain")) {
//                        System.err.format("New file '%s'" +
//                                " is not a plain text file.%n", filename);
//                        continue;
//                    }
//                } catch (IOException x) {
//                    System.err.println(x);
//                    continue;
//                }

                // Email the file to the
                //  specified email alias.
                System.out.format("Emailing file %s%n", filename);
                //Details left to reader....
            }

            // Reset the key -- this step is critical if you want to
            // receive further watch events.  If the key is no longer valid,
            // the directory is inaccessible so exit the loop.
            boolean valid = key.reset();
            if (!valid) {
                break;
            }
        }
    }

    public static void main(String arg[]) throws IOException {
        FileReader fileReader = new FileReader();
        fileReader.watch();
    }

}