Javahttp

Making HTTP Requests

Sometimes we would like to call other HTTP services from within a play application. Play supports this task via its play.libs.WS library which provides a way to make asynchronous HTTP calls.

Any calls made by play.libs.WS should return a play.libs.F.Promise<play.libs.WS.Response> which we can later handle with play's asynchronous mechanisms.

A short introduction

Hello Get

import play.libs.*;

F.Promise<WS.Response> promise = WS.url("http://mysite.com").get();

WS.Response res = promise.get();

String body = res.getBody();

int status = res.getStatus();

String contentType = res.getHeader("Content-Type");

org.w3c.dom.Document doc = res.asXml();

org.codehaus.jackson.JsonNode json = res.asJson();

Note: in this example we used play.libs.F.Promise#get to retrieve the result of the promise in a blocking fashion, however, since this is an async call, one might want to avoid blocking by handling the promise via play.libs.F.Promise#onRedeem callback or play.libs.F.Promise#map or even play.libs.F.Promise#flatMap.

Please consult the javadoc for more information

Hello Post

import play.libs.*;
import com.ning.http.client.Realm;

F.Promise<WS.Response> jpromise = WS.url("http://mysite.com/post")
   .setHeader("Content-Type","application/x-www-form-urlencoded")
   .setAuth("peter","superSecret",Realm.AuthScheme.SPNEGO)
   .setQueryParam("myqparam","1")
   .post("param1=foo");
String body = jpromise.get().getBody();
//and body should contain AnyContentAsUrlFormEncoded

For more information please see the api doc here