Asynchronous HTTP Client for Java

Question

As a relative newbie in the Java world, I am finding many things frustratingly obtuse to accomplish that are relatively trivial in many other frameworks. A primary example i

Answer 1

httpunit and htmlunit are 2 customizable and configurable Java http clients able to anything a browser such as simulate firefox, headless browsing, scheduled software clients and agents.

Answer 2

there are libraries and frameworks written on top of NIO/Netty - RxNetty and Vertx which can be helpful to write asynchronous HTTP client

Below is an example code using vertx

public class Client extends AbstractVerticle {

  @Override
  public void start() throws Exception {
    //lambda callback would be called when the response comes back
    vertx.createHttpClient().getNow(8080, "localhost", "/", resp -> {
      System.out.println("Got response " + resp.statusCode());
      resp.bodyHandler(body -> {
        System.out.println("Got data " + body.toString("ISO-8859-1"));
      });
    });
   //this code statement will execute before response comes back
   System.out.println("I am not blocked");
  }
}

you can find the full blown example code from here

Answer 3

Looks like you want (a part of) NIO -- there's a good tutorial here, the asynchronous networking part starts at p. 30 and there are many useful links at the end.

Answer 4

Asyncweb provides an asynchronous http client along with its http server. Available for download from the following location:

https://svn.apache.org/repos/asf/mina/asyncweb/trunk

Answer 5

I just stumbled upon the asynchronous HTTP client implemented within Geronimo. You might also want to take a look it, at http://svn.apache.org/viewvc/geronimo/sandbox/AsyncHttpClient/ - Caveat: the latest commit seems over a year old.

Another project building an asynchronous HTTP client is xsocket: xsocket.sourceforge.net

Answer 6

Take also a look into http://www.javaworld.com/javaworld/jw-03-2008/jw-03-asynchhttp.html This article discusses async HTTP based on a HttpClient named xLightweb