程序包 ohos.utils

类 FileWatcher

java.lang.Object

ohos.utils.FileWatcher

public class FileWatcher
extends Object

Provides the capability of monitoring status changes of a specified file directory.

To monitor files, you need to first implement the FileWatcher.EventHandler class that processes the events of status changes on the monitored file directory. Then, you should use the addWatch(java.nio.file.Path,ohos.utils.FileWatcher.EventHandler,boolean,java.nio.file.WatchEvent.Kind...) method to add the file directory to be monitored and the associated event handler. When a file in the specified directory is changed, the event handler will be triggered to process the event.

The following events defined in StandardWatchEventKinds are supported by FileWatcher:

• StandardWatchEventKinds.ENTRY_CREATE
• StandardWatchEventKinds.ENTRY_DELETE
• StandardWatchEventKinds.ENTRY_MODIFY

从以下版本开始:

3

嵌套类概要

嵌套类

限定符和类型	类	说明
static interface	FileWatcher.EventHandler	Provides a handler for processing file events.

构造器概要

构造器

构造器	说明
FileWatcher()	Default constructor used to create a FileWatcher instance.

方法概要

限定符和类型	方法	说明
void	addWatch(Path directory, FileWatcher.EventHandler eventHandler, boolean isRecursive, WatchEvent.Kind<?>... events)	Adds a watcher to monitor a specified file directory.

从类继承的方法 java.lang.Object

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

构造器详细资料

FileWatcher

public FileWatcher()

Default constructor used to create a FileWatcher instance.

抛出:

RuntimeException - Throws this exception if the file watcher service is not available.

从以下版本开始:

3

方法详细资料

addWatch

public void addWatch(Path directory,
                     FileWatcher.EventHandler eventHandler,
                     boolean isRecursive,
                     WatchEvent.Kind<?>... events)

Adds a watcher to monitor a specified file directory.

You can specify the file events to monitor. If no event is specified, all events on the file directory are monitored.

参数:

directory - Indicates the file directory to monitor.

eventHandler - Indicates the event handler to add for the specified file directory.

isRecursive - Specifies whether to recursively monitor the specified file directory.

抛出:

NullPointerException - Throws this exception if directory or eventHandler is null.

RuntimeException - Throws this exception if adding the watcher fails.

从以下版本开始:

3