br.com.objectos.fs.watch

Class Watch

java.lang.Object

br.com.objectos.fs.watch.Watch

public final class Watch
extends Object

Provides static methods for configurating and creating a file system watch service.

For example, a crude service that uploads to a remote location any file created in a directory could be implemented like this:

     Watch.Listener listener = new SimpleWatchListener() {
       final Uploaded uploader = createUploader();

       @Override
       public final void onRegularFileCreated(RegularFile file) {
         // uploader must handle any exception
         uploader.upload(file);
       }
     };

     Watch.Service service = Watch.createService(
         Watch.watchDirectory(
             LocalFs.getDirectory("/srv/upload"),
             listener,
             Watch.CREATED
         )
     );

     Services.start(service);
 

Since:

2

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Watch.Event The events available for watching.
static interface	Watch.Listener A listener for previously registered file system events.
static interface	Watch.Option Represents an option for configuring a watch service.
static interface	Watch.Service The watch service interface, allows for starting and stopping the watch service.
static interface	Watch.ServiceBuilder A façade for configuring a watch service builder.

Field Summary

Fields

Modifier and Type	Field and Description
static Watch.Event	CREATED The Watch.Event.CREATED constant (provided for convenience).
static Watch.Event	DELETED The Watch.Event.DELETED constant (provided for convenience).
static Watch.Event	MODIFIED The Watch.Event.MODIFIED constant (provided for convenience).

Method Summary

Modifier and Type	Method and Description
static Watch.Service	createService(Watch.Option... options) Creates and returns a new watch service with the specified options.
static Watch.Option	watchDirectory(Directory directory, Watch.Listener listener, Watch.Event event) Returns a new configuration option to watch the specified directory with the specified listener for the specified event.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CREATED

public static final Watch.Event CREATED

The Watch.Event.CREATED constant (provided for convenience).

DELETED

public static final Watch.Event DELETED

The Watch.Event.DELETED constant (provided for convenience).

MODIFIED

public static final Watch.Event MODIFIED

The Watch.Event.MODIFIED constant (provided for convenience).

Method Detail

createService

public static Watch.Service createService(Watch.Option... options)
                                   throws IOException

Creates and returns a new watch service with the specified options.

Once created, watch service instance cannot be modified. Therefore, all registrations must be supplied at creation time.

Parameters:

options - the options to use for creating the watch servcie

Returns:

a newly created watch service with the specified options

Throws:

IOException - if an I/O error occurs

watchDirectory

public static Watch.Option watchDirectory(Directory directory,
                                          Watch.Listener listener,
                                          Watch.Event event)

Returns a new configuration option to watch the specified directory with the specified listener for the specified event.

Parameters:

directory - the directory to watch for events

listener - the listener instance that will act upon the watched events

event - the event to watch for

Returns:

a new configuration option to use with the createService(Option...) service factory method