Thursday, October 7, 2010

Async HTTP Client 1.2.0

Async HTTP Client 1.2.0

Intro

About month ago we released async-http-client 1.1.0.
During this month we received lots of contributions and user feedback.
We took all of this great feedback into consideration,
and here it is: lots of bug fixes and new features in async-http-client are ready to be released.
You can get it from Maven Central near you.

Highlights

To cut the long story short here are highlights of few new features.
  • JDK based provider

    This release support a new AsyncHttpProvider based on JDK's URLConnection.
    This provider can be used in environments that aren't supporting NIO.
    AsyncHttpClient client = new AsyncHttpClient(new JDKAsyncHttpProvider(config));
  • Authentication

    The library now support 3 authentication scheme: Basic, Digest and NTLM.
    RequestBuilder r = client.prepareGet(url)
    .setRealm((new Realm.RealmBuilder())
    .setScheme(AuthScheme)
    .setPrincipal(user)
    .setPassword(admin)
    .setUsePreemptiveAuth(true).build());
    AuthScheme can be BASIC, DIGEST or NTLM.
  • SSL Tunneling support

    This release also adds support for SSL Tunneling.
    AsyncHttpClientConfig.Builder b = new AsyncHttpClientConfig.Builder();
    b.setFollowRedirects(true);

    ProxyServer ps = new ProxyServer(ProxyServer.Protocol.HTTPS, "127.0.0.1", port1);
    b.setProxyServer(ps);

    AsyncHttpClientConfig config = b.build();
    AsyncHttpClient asyncHttpClient = new AsyncHttpClient(config);

    RequestBuilder rb = new RequestBuilder("GET").setUrl(url);
    Future<Response> responseFuture = asyncHttpClient.executeRequest(rb.build(), new AsyncCompletionHandlerBase() {

    public void onThrowable(Throwable t) {
    log.debug(t);
    }

    @Override
    public Response onCompleted(Response response) throws Exception {
    return response;
    }
    });
  • WebDav

    WebDav is now supported and can be used with two interfaces.
    • Low level
      AsyncHttpClient c = new AsyncHttpClient();

      Request mkcolRequest = new RequestBuilder("MKCOL").setUrl("http://127.0.0.1:8080/folder1").build();
      Response response = c.executeRequest(mkcolRequest).get();

      Request putRequest = new RequestBuilder("PUT").setUrl("http://127.0.0.1:8080/folder1/Test.txt").setBody("this is a test").build();
      response = c.executeRequest(putRequest).get();

      Request propFindRequest = new RequestBuilder("PROPFIND").setUrl("http://127.0.0.1:8080/folder1/Test.txt").build();
      response = c.executeRequest(propFindRequest).get();

      // Check the response.
      response.getStatusCode(); //Will return 207
      response.getResponseBody().contains("<status>HTTP/1.1 200 OK</status>"));
    • High level

      You can also use a special AsyncHandler which construct a response
      based on the webdav response's code.
      AsyncHttpClient c = new AsyncHttpClient();

      Request mkcolRequest = new RequestBuilder("MKCOL").setUrl("http://127.0.0.1:8080/folder1").build();
      Response response = c.executeRequest(mkcolRequest).get();
      assertEquals(response.getStatusCode(), 201);

      Request propFindRequest = new RequestBuilder("PROPFIND").setUrl("http://127.0.0.1:8080/folder1/").build();
      WebDavResponse webDavResponse = c.executeRequest(propFindRequest, new WebDavCompletionHandlerBase<WebDavResponse>() {

      @Override
      public WebDavResponse onCompleted(WebDavResponse response) throws Exception {
      return response;
      }
      }).get();

      webDavResponse.getStatusCode(); // will return 200.
  • Zero copy

    Sometimes you need to just download some content, with out
    copying/inspecting the bytes in memory, just download and store.
    File file = new File(url.toURI());

    File tmp = new File(System.getProperty("java.io.tmpdir") + File.separator + "zeroCopy.txt");
    final FileOutputStream stream = new FileOutputStream(tmp);
    // Upload a file using setBody(File);
    Future<Response> f = client.preparePost("http://127.0.0.1:" + port1 + "/").setBody(file).execute(new AsyncHandler<Response>() {
    public void onThrowable(Throwable t) {}

    public STATE onBodyPartReceived(HttpResponseBodyPart bodyPart) throws Exception {
    bodyPart.writeTo(stream);
    // Copy the bytes directly to a File. In our case it is an FileInputStream
    return STATE.CONTINUE;
    }

    public STATE onStatusReceived(HttpResponseStatus responseStatus) throws Exception {
    return STATE.CONTINUE;
    }

    public STATE onHeadersReceived(HttpResponseHeaders headers) throws Exception {
    return STATE.CONTINUE;
    }

    public Response onCompleted() throws Exception {
    return null;
    }
    });

    Response resp = f.get();
    stream.close();
  • Automatic HTTPS redirects

    Another new feature is we do support redirect from http to HTTPS automatically:
    AsyncHttpClientConfig cg = new AsyncHttpClientConfig.Builder().setFollowRedirects(true).build();
    AsyncHttpClient c = new AsyncHttpClient(cg);

    Response response = c.preparePost(url).execute().get();
    If the server redirect us to https, we will follow the new url
    without any issue.

Changelog

Friday, September 10, 2010

Asynchronous HTTP Client for Clojure and Twitter Streaming API

http.async.client & Twitter Streaming API

http.async.client is a Clojure library based on Asynchronous Http Client for Java which runs on top of Netty Project.

So much for introduction, lets see some sample code that uses Twitter streaming api.

Importing:

(ns twitter-sample
(:require [http.async.client :as c]
[org.danlarkin.json :as j]))

Settings and helper to print twits as they fly by:

(def u "username")
(def p "password")

(defn print-user-and-text [s]
(let [twit (j/decode-from-str s)
user (:screen_name (:user twit))
text (:text twit)]
(println user "=>" text)))

Lets read statuses/sample:

(doseq [twit-str (c/string
(c/stream-seq :get "http://stream.twitter.com/1/statuses/sample.json"
:auth {:user u :password p}))]
(print-user-and-text twit-str))

Or statuses/filter:

(doseq [twit-str (c/string
(c/stream-seq :post "http://stream.twitter.com/1/statuses/filter.json"
:body {"track" "basketball,football,baseball,footy,soccer"}
:auth {:user u :password p}))]
(print-user-and-text twit-str))

Those two samples show also how to consume HTTP Streams as clojure.core/seq, a new feature that was introduced in v0.2.0.

You can also handle sequences via callbacks.

Requesting HTTP resources that are not streams is even simpler:

(let [response (c/GET "http://github.com/neotyk/http.async.client/")]
(c/await response)
(c/string response))

There is extensive documentation available on the github pages of the project, you can also find Changelog and API.

Big thanks go to Amsterdam Clojurians, this library received so much love and help from this group.
Kudos to Jeanfrancois Arcand for starting async-http-client recently reaching the 1.1.0 release.

I would love to hear from you what you think of this library.