But I can't listen for file modify event. I can successfully listen for file created event. Import static .I want to watch a directory for file changes.
Filewatcher java 8 code#
The following is the complete code for the watch event example. The watch service exits when either the thread exits or when it is closed by invoking its close() method. If this method returns false, the key is no longer valid and the infinite loop exits. The events for the key have been processed, and it is required to put the key back into a ready state by invoking watch key’s reset() method. FileWatcher fileWatcher new FileWatcher (path, fileHandlerTest, StandardWatchEventKinds.ENTRYCREATE) Now Create and start a new Thread. WatchEvent pathEvent = (WatchEvent) genericEvent Create an instance of a FileWatcher by passing path, an instance of an Implemented FileHandler, and types of file events that you want to monitor separated by commas. The path is the relative path between the directory registered with the watch service, and the entry that is created, deleted, or modified.The file’s path information can be used to do something – for example print the file name. The watch event’s context() method returns the Path object associated with the event. Retrieve the file path associated with the event This method’s usage is shown in the following code snippet. If no queued key is available, this method waits. The watch service’s take() method returns a queued key. When an event occurs, the watch key is signaled and placed into the watch service’s queue.
This is implemented as an infinite loop that waits for incoming events. Note the directory being watched is an existing directory.
Filewatcher java 8 registration#
This is a token representing the registration of a Path object with a watch service. WatchKey watchKey = path.register(watchService, StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_DELETE) Ī WatchKey instance is returned for each directory registered. Specify the type of events to monitor – in this case file modify and delete. The Path extends the Watchable, so the directory to be monitored is registered as a Path object. Any object that implements the Watchable interface can be registered. Register one or more objects with the watch service. Create a new watch service for the file system WatchService watchService = FileSystems.getDefault().newWatchService() The program is explained in the following steps: 2.1. The kind of events monitored are modify and delete that the directory is modified (like adding a file to the directory) or a file is deleted from the directory. The example application watches a directory for changes by using watch service. This example shows how the watch events are used in a watch service application. The events are of type WatchEvent.Kind, except OVERFLOW which is of type WatchEvent.Kind. The overflow is a special event for lost or discarded events.
These identify the type of operation on a directory – an entry is created, deleted or modified in the directory.
The StandardWatchEventKinds class has four fields (constants) that identify the event kinds: ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY and OVERFLOW. The StandardWatchEventKinds class defines the standard event kinds. The kind() method returns the event kind (an identifier), defined by WatchEvent.Kind interface. IntroductionĪ watch event is classified by its kind.
0 kommentar(er)
