FileModificationPollingMonitor (common 0.9.0 API)

java.lang.Object
- io.pravega.common.io.filesystem.FileModificationPollingMonitor

All Implemented Interfaces:

FileModificationMonitor
```
public class FileModificationPollingMonitor
extends java.lang.Object
implements FileModificationMonitor
```
Monitors for modifications to the specified file using a polling-based mechanism and performs the specified action (in the form of a callback) upon detection of a file modification. Unlike FileModificationEventWatcher, which doesn't work for monitoring modifications to a file which is a symbolic link to another file, an object of this class works for such files as well. However, since this object uses a polling-based mechanism - unlike the event-based mechanism used by FileModificationEventWatcher, lists files on each iteration and compares the output, this object is highly likely to be less efficient than an object of FileModificationEventWatcher - CPU cycles-wise.

Constructor Summary

Constructors
Constructor	Description
`FileModificationPollingMonitor(@NonNull java.nio.file.Path fileToWatch, @NonNull java.util.function.Consumer<java.io.File> callback)`	Creates a new instance.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`getPollingInterval()`
`void`	`startMonitoring()`	Start monitoring.
`void`	`stopMonitoring()`	Stop monitoring.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - FileModificationPollingMonitor
```
public FileModificationPollingMonitor(@NonNull
                                      @NonNull java.nio.file.Path fileToWatch,
                                      @NonNull
                                      @NonNull java.util.function.Consumer<java.io.File> callback)
                               throws java.io.FileNotFoundException
```
    Creates a new instance.
    
    Parameters:
    
    fileToWatch - the file to watch
    
    callback - the callback to invoke when a modification to the fileToWatch is detected
    
    Throws:
    
    java.nio.file.InvalidPathException - if fileToWatch is invalid
    
    java.io.FileNotFoundException - when a file at specified path fileToWatch does not exist
    
    java.lang.NullPointerException - if either fileToWatch or callback is null
- Method Detail
  - startMonitoring
```
public void startMonitoring()
```
    Description copied from interface: FileModificationMonitor
    
    Start monitoring.
    
    Specified by:
    
    startMonitoring in interface FileModificationMonitor
  - stopMonitoring
```
public void stopMonitoring()
```
    Description copied from interface: FileModificationMonitor
    
    Stop monitoring.
    
    Specified by:
    
    stopMonitoring in interface FileModificationMonitor
  - getPollingInterval
```
public int getPollingInterval()
```