Status: released to Maven Central
Requires Java 7.
Observable utilities for files:
- tail a file (either lines or byte[])
- trigger tail updates using Java 7 and later NIO
WatchService
events - or trigger tail updates using any Observable
- stream
WatchEvent
s from aWatchService
- backpressure support
- tested on Linux and Windows 7 (not OSX, help appreciated!)
Maven site reports are here including javadoc.
Add this maven dependency to your pom.xml:
<dependency>
<groupId>com.github.davidmoten</groupId>
<artifactId>rxjava-file</artifactId>
<version>0.4</version>
</dependency>
git clone https://github.com/davidmoten/rxjava-file
cd rxjava-file
mvn clean install
###Tail a text file with NIO
Tail the lines of the text log file /var/log/server.log
as an Observable<String>
:
import com.github.davidmoten.rx.FileObservable;
import rx.Observable;
import java.io.File;
Observable<String> items =
FileObservable.tailer()
.file("/var/log/server.log")
.startPosition(0)
.sampleTimeMs(500)
.chunkSize(8192)
.utf8()
.tailText();
or, using defaults (will use default charset):
Observable<String> items =
FileObservable.tailer()
.file("/var/log/server.log")
.tailText();
Note that if you want the Observable<String>
to be emitting line by line then wrap
it with a call like StringObservable.split(observable, "\n")
. StringObservable
is in the RxJava rxjava-string artifact.
###Tail a text file without NIO
The above example uses a WatchService
to generate WatchEvent
s to prompt rereads of the end of the file to perform the tail.
To use polling instead (say every 5 seconds):
Observable<String> items =
FileObservable.tailer()
.file(new File("var/log/server.log"))
.source(Observable.interval(5, TimeUnit.SECONDS)
.tailText();
###Tail a binary file with NIO
Observable<byte[]> items =
FileObservable.tailer()
.file("/tmp/dump.bin")
.tail();
###Tail a binary file without NIO
Observable<byte[]> items =
FileObservable.tailer()
.file("/tmp/dump.bin")
.source(Observable.interval(5, TimeUnit.SECONDS)
.tail();