@Test
public void parseLines() throws Exception {
final Source<ByteString, NotUsed> compressed = Source.single(gzip("Hello World"));
// #decompress-gzip
final Source<String, NotUsed> uncompressed =
compressed.via(Compression.gunzip(100)).map(b -> b.utf8String());
// #decompress-gzip
uncompressed.runWith(Sink.head(), mat).toCompletableFuture().get(1, TimeUnit.SECONDS);
}
public void streamFile()
throws IOException, FileNotFoundException, InterruptedException, ExecutionException {
String url = "http://example.com";
// #stream-to-file
File file = File.createTempFile("stream-to-file-", ".txt");
FileOutputStream outputStream = new FileOutputStream(file);
// Make the request
CompletionStage<StreamedResponse> futureResponse = ws.url(url).setMethod("GET").stream();
CompletionStage<File> downloadedFile =
futureResponse.thenCompose(
res -> {
Source<ByteString, ?> responseBody = res.getBody();
// The sink that writes to the output stream
Sink<ByteString, scala.concurrent.Future<scala.runtime.BoxedUnit>> outputWriter =
Sink.<ByteString>foreach(bytes -> outputStream.write(bytes.toArray()));
// Converts the materialized Scala Future into a Java8 `CompletionStage`
Sink<ByteString, CompletionStage<?>> convertedOutputWriter =
outputWriter.mapMaterializedValue(FutureConverters::toJava);
// materialize and run the stream
CompletionStage<File> result =
responseBody
.runWith(convertedOutputWriter, materializer)
.whenComplete(
(value, error) -> {
// Close the output stream whether there was an error or not
try {
outputStream.close();
} catch (IOException e) {
}
})
.thenApply(v -> file);
return result;
});
// #stream-to-file
downloadedFile.toCompletableFuture().get();
file.delete();
}
@Test
public void demonstrateFilterAndMap() {
final SilenceSystemOut.System System = SilenceSystemOut.get();
// #first-sample
// #authors-filter-map
final Source<Author, NotUsed> authors =
tweets.filter(t -> t.hashtags().contains(AKKA)).map(t -> t.author);
// #first-sample
// #authors-filter-map
new Object() {
// #authors-collect
JavaPartialFunction<Tweet, Author> collectFunction =
new JavaPartialFunction<Tweet, Author>() {
public Author apply(Tweet t, boolean isCheck) {
if (t.hashtags().contains(AKKA)) {
if (isCheck) return null; // to spare the expensive or side-effecting code
return t.author;
} else {
throw noMatch();
}
}
};
final Source<Author, NotUsed> authors = tweets.collect(collectFunction);
// #authors-collect
};
// #first-sample
// #authors-foreachsink-println
authors.runWith(Sink.foreach(a -> System.out.println(a)), mat);
// #first-sample
// #authors-foreachsink-println
// #authors-foreach-println
authors.runForeach(a -> System.out.println(a), mat);
// #authors-foreach-println
}
public void streamSimpleRequest() {
String url = "http://example.com";
// #stream-count-bytes
// Make the request
CompletionStage<StreamedResponse> futureResponse = ws.url(url).setMethod("GET").stream();
CompletionStage<Long> bytesReturned =
futureResponse.thenCompose(
res -> {
Source<ByteString, ?> responseBody = res.getBody();
// Count the number of bytes returned
Sink<ByteString, scala.concurrent.Future<Long>> bytesSum =
Sink.fold(0L, (total, bytes) -> total + bytes.length());
// Converts the materialized Scala Future into a Java8 `CompletionStage`
Sink<ByteString, CompletionStage<Long>> convertedBytesSum =
bytesSum.mapMaterializedValue(FutureConverters::toJava);
return responseBody.runWith(convertedBytesSum, materializer);
});
// #stream-count-bytes
}