Java example for sending non-blocking http request from AKKA

Question

The AKKA documentation says that

... Actors should not block (i.e. passively wait while occupying Thread) on some external object, which may be a lock, a network socket, etc. Blocking operations must be performed in some special streamlined stream that sends messages to actors who will act on them. source http://doc.akka.io/docs/akka/2.0/general/actor-systems.html#Actor_Best_Practices

At the moment, I have found the following information:

• I read Sending an outgoing HTTP request from Akka / Scala and checked the example at https://github.com/dsciamma/fbgl1

• I found the following article http://nurkiewicz.blogspot.de/2012/11/non-blocking-io-discovering-akka.html explaining how to use https://github.com/AsyncHttpClient/async-http-client . without blocking the http client using akka. But it is written in Scala.

How can I write an actor who makes non-blocking HTTP requests?

He should omit the remote URL page as a file and send the sent file file to the main actor. the master actor then sends this request to the parser to parse the file ...

Answer 1

I implemented it this way.

public class ReduceActor extends UntypedActor { @Override public void onReceive(Object message) throws Exception { if (message instanceof URI) { URI url = (URI) message; AsyncHttpClient asyncHttpClient = new AsyncHttpClient(); asyncHttpClient.prepareGet(url.toURL().toString()).execute(new AsyncCompletionHandler<Response>() { @Override public Response onCompleted(Response response) throws Exception { File f = new File("e:/tmp/crawler/" + UUID.randomUUID().toString() + ".html"); // Do something with the Response // ... // System.out.println(response1.getStatusLine()); FileOutputStream fao = new FileOutputStream(f); IOUtils.copy(response.getResponseBodyAsStream(), fao); System.out.println("File downloaded " + f); getSender().tell(new WordCount(f)); return response; } @Override public void onThrowable(Throwable t) { // Something wrong happened. } }); } else unhandled(message); } 

Answer 2

In the last answer, Korea uses the wrong link for the sender, the correct way to do this is:

 public class ReduceActor extends UntypedActor { @Override public void onReceive(Object message) throws Exception { if (message instanceof URI) { URI url = (URI) message; AsyncHttpClient asyncHttpClient = new AsyncHttpClient(); final ActorRef sender = getSender(); asyncHttpClient.prepareGet(url.toURL().toString()).execute(new AsyncCompletionHandler<Response>() { @Override public Response onCompleted(Response response) throws Exception { File f = new File("e:/tmp/crawler/" + UUID.randomUUID().toString() + ".html"); // Do something with the Response // ... // System.out.println(response1.getStatusLine()); FileOutputStream fao = new FileOutputStream(f); IOUtils.copy(response.getResponseBodyAsStream(), fao); System.out.println("File downloaded " + f); sender.tell(new WordCount(f)); return response; } @Override public void onThrowable(Throwable t) { // Something wrong happened. } }); } else unhandled(message); } 

Checkout this second branch akka: fooobar.com/questions/1444868 / ...