How to use sendFile method for sending the file located on internet? - vert.x

Question

I want to use Vert.x routingContext.response().sendFile method to read the file from internet and send it to some handler.
I have tried to use routingContext.response().sendFile for files located on my local system which works fine but instead of local system file when I am using file located on internet, I am getting error java.io.FileNotFoundException
String filename = "http://www.awitness.org/prophecy.zip";
routingContext.response().sendFile(filename, asr->{
if(asr.succeeded()) {
System.out.println("success....");
} else {
System.out.println("Something went wrong " + asr.cause());
}
});
Getting this output:
Something went wrong java.io.FileNotFoundException

Answer 1

That's because sendFile() takes local file path as argument.
Best solution would be to download this file, and serve it from your application.
Worse solution is to download this file on demand, save it using vertx.fileSystem().createTempFile(), and still serve it locally.
Now, for the sake of the argument, let's decided that you would like to go down the second path. How would you do that? You can try something like this:
final Vertx vertx = Vertx.vertx();
final Router router = Router.router(vertx);
WebClient c = WebClient.create(vertx);
String temp = vertx.fileSystem().createTempFileBlocking("", "");
c.get("www.awitness.org", "/prophecy.zip").send(r -> {
if (r.succeeded()) {
Buffer buffer = r.result().body();
vertx.fileSystem().writeFileBlocking(temp, buffer);
}
});
router.route("/").produces("application/zip").handler(ctx -> {
ctx.response().sendFile(temp);
});
I'm using blocking APIs only for the sake of simplicity. Correct ones are the async ones.