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Null Pointer Exception (not resolved) and Unable to match WSRsponse for result in game 2.4 (this part is resolved I guess)

I am trying to write a simple application in Play2.4. I want to get a page and show it on my localhost which will act as a proxy. Below is my action in the controller:

public class Proxy extends Controller{
    @Inject WSClient ws;

    public Promise<Result> index(String url){
        WSRequest request = ws.url(url);
        //Promise<WSResponse> responsePromise = request.get();
        return Promise.promise(() -> request.get())
                .map((WSResponse wsresponse) -> ok(wsresponse.getBody()).as("text/html"));
    }
}

I am getting an error no suitable method found for map((WSRespons[...]tml"))

. I am very new to Play as well as Java8. Could you please help me here or point me in the right direction.

Also, you should use WSResponse or just Response. There is very little documentation in this regard.

Basically I want the above task to be done in async. Thanks to

PS: I followed this link https://www.playframework.com/documentation/2.4.x/JavaAsync and https://www.playframework.com/documentation/2.3.x/JavaAsync .

PPS. AS suggested in the comments by @MonCalamari I used return request.get().map((r) -> ok(r.getBody()).as("text/html"));

However now I am getting weird

Execution exception
[NullPointerException: scheme]

in line

return request.get().map((r) -> ok(r.getBody()).as("text/html"));

I've tried going through the docs and other sources and to no avail. Any help would be greatly appreciated. Thanks to

Can't get answers ... went through the stack trace but couldn't get anything ... Below is the stack trace in case anyone is interested.

play.api.http.HttpErrorHandlerExceptions$$anon$1: Execution exception[[NullPointerException: scheme]]
    at play.api.http.HttpErrorHandlerExceptions$.throwableToUsefulException(HttpErrorHandler.scala:254) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.http.DefaultHttpErrorHandler.onServerError(HttpErrorHandler.scala:180) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.GlobalSettings$class.onError(GlobalSettings.scala:179) [play_2.11-2.4.0.jar:2.4.0]
    at play.api.DefaultGlobal$.onError(GlobalSettings.scala:212) [play_2.11-2.4.0.jar:2.4.0]
    at play.api.http.GlobalSettingsHttpErrorHandler.onServerError(HttpErrorHandler.scala:94) [play_2.11-2.4.0.jar:2.4.0]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$9$$anonfun$apply$1.applyOrElse(PlayDefaultUpstreamHandler.scala:158) [play-netty-server_2.11-2.4.0.jar:2.4.0]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$9$$anonfun$apply$1.applyOrElse(PlayDefaultUpstreamHandler.scala:155) [play-netty-server_2.11-2.4.0.jar:2.4.0]
    at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36) [scala-library-2.11.6.jar:na]
    at scala.util.Failure$$anonfun$recover$1.apply(Try.scala:215) [scala-library-2.11.6.jar:na]
    at scala.util.Try$.apply(Try.scala:191) [scala-library-2.11.6.jar:na]
    at scala.util.Failure.recover(Try.scala:215) [scala-library-2.11.6.jar:na]
    at scala.concurrent.Future$$anonfun$recover$1.apply(Future.scala:324) [scala-library-2.11.6.jar:na]
    at scala.concurrent.Future$$anonfun$recover$1.apply(Future.scala:324) [scala-library-2.11.6.jar:na]
    at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:32) [scala-library-2.11.6.jar:na]
    at play.api.libs.iteratee.Execution$trampoline$.executeScheduled(Execution.scala:109) [play-iteratees_2.11-2.4.0.jar:2.4.0]
    at play.api.libs.iteratee.Execution$trampoline$.execute(Execution.scala:71) [play-iteratees_2.11-2.4.0.jar:2.4.0]
    at scala.concurrent.impl.CallbackRunnable.executeWithValue(Promise.scala:40) [scala-library-2.11.6.jar:na]
    at scala.concurrent.impl.Promise$DefaultPromise.tryComplete(Promise.scala:248) [scala-library-2.11.6.jar:na]
    at scala.concurrent.Promise$class.complete(Promise.scala:55) [scala-library-2.11.6.jar:na]
    at scala.concurrent.impl.Promise$DefaultPromise.complete(Promise.scala:153) [scala-library-2.11.6.jar:na]
    at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:23) [scala-library-2.11.6.jar:na]
    at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:40) [akka-actor_2.11-2.3.11.jar:na]
    at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:397) [akka-actor_2.11-2.3.11.jar:na]
    at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) [scala-library-2.11.6.jar:na]
    at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) [scala-library-2.11.6.jar:na]
    at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) [scala-library-2.11.6.jar:na]
    at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) [scala-library-2.11.6.jar:na]
Caused by: java.lang.NullPointerException: scheme
    at com.ning.http.client.uri.Uri.<init>(Uri.java:56) ~[async-http-client-1.9.21.jar:na]
    at com.ning.http.client.uri.Uri.create(Uri.java:32) ~[async-http-client-1.9.21.jar:na]
    at com.ning.http.client.uri.Uri.create(Uri.java:25) ~[async-http-client-1.9.21.jar:na]
    at com.ning.http.client.RequestBuilderBase.setUrl(RequestBuilderBase.java:307) ~[async-http-client-1.9.21.jar:na]
    at com.ning.http.client.RequestBuilder.setUrl(RequestBuilder.java:165) ~[async-http-client-1.9.21.jar:na]
    at play.libs.ws.ning.NingWSRequest.buildRequest(NingWSRequest.java:401) ~[play-java-ws_2.11-2.4.0.jar:2.4.0]
    at play.libs.ws.ning.NingWSRequest.execute(NingWSRequest.java:394) ~[play-java-ws_2.11-2.4.0.jar:2.4.0]
    at play.libs.ws.ning.NingWSRequest.execute(NingWSRequest.java:389) ~[play-java-ws_2.11-2.4.0.jar:2.4.0]
    at play.libs.ws.ning.NingWSRequest.get(NingWSRequest.java:272) ~[play-java-ws_2.11-2.4.0.jar:2.4.0]
    at controllers.Proxy.index(Proxy.java:46) ~[classes/:2.4.0]
    at router.Routes$$anonfun$routes$1$$anonfun$applyOrElse$4$$anonfun$apply$4.apply(Routes.scala:157) ~[classes/:na]
    at router.Routes$$anonfun$routes$1$$anonfun$applyOrElse$4$$anonfun$apply$4.apply(Routes.scala:157) ~[classes/:na]
    at play.core.routing.HandlerInvokerFactory$$anon$5.resultCall(HandlerInvoker.scala:139) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.core.routing.HandlerInvokerFactory$JavaActionInvokerFactory$$anon$14$$anon$3$$anon$1.invocation(HandlerInvoker.scala:127) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.core.j.JavaAction$$anon$1.call(JavaAction.scala:65) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.http.DefaultHttpRequestHandler$1.call(DefaultHttpRequestHandler.java:20) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.core.j.JavaAction$$anonfun$7.apply(JavaAction.scala:85) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.core.j.JavaAction$$anonfun$7.apply(JavaAction.scala:85) ~[play_2.11-2.4.0.jar:2.4.0]
    at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24) [scala-library-2.11.6.jar:na]
    at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24) [scala-library-2.11.6.jar:na]
    at play.core.j.HttpExecutionContext$$anon$2.run(HttpExecutionContext.scala:40) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.libs.iteratee.Execution$trampoline$.execute(Execution.scala:70) [play-iteratees_2.11-2.4.0.jar:2.4.0]
    at play.core.j.HttpExecutionContext.execute(HttpExecutionContext.scala:32) ~[play_2.11-2.4.0.jar:2.4.0]
    at scala.concurrent.impl.Future$.apply(Future.scala:31) ~[scala-library-2.11.6.jar:na]
    at scala.concurrent.Future$.apply(Future.scala:492) ~[scala-library-2.11.6.jar:na]
    at play.core.j.JavaAction.apply(JavaAction.scala:85) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:105) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:105) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.utils.Threads$.withContextClassLoader(Threads.scala:21) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:104) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:103) ~[play_2.11-2.4.0.jar:2.4.0]
    at scala.Option.map(Option.scala:146) ~[scala-library-2.11.6.jar:na]
    at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:103) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:96) ~[play_2.11-2.4.0.jar:2.4.0]
    at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:524) ~[play-iteratees_2.11-2.4.0.jar:2.4.0]
    at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:524) ~[play-iteratees_2.11-2.4.0.jar:2.4.0]
    at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:560) ~[play-iteratees_2.11-2.4.0.jar:2.4.0]
    at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:560) ~[play-iteratees_2.11-2.4.0.jar:2.4.0]
    at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$13.apply(Iteratee.scala:536) ~[play-iteratees_2.11-2.4.0.jar:2.4.0]
    at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$13.apply(Iteratee.scala:536) ~[play-iteratees_2.11-2.4.0.jar:2.4.0]
    at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24) [scala-library-2.11.6.jar:na]
    at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24) [scala-library-2.11.6.jar:na]
    ... 6 common frames omitted
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1 answer


The second part of the question was answered by @Mon Calamari. We need to use return request.get().map((r) -> ok(r.getBody()).as("text/html"));

. As for the first part, the question was 2 parts.

Check if we have a valid url or not. There are many ways to do this. I have done with the following simple approach.

try {
    URL url = new URL("http://www.yoursite.com/");
    URLConnection conn = url.openConnection();
    conn.connect();
} catch (MalformedURLException e) {
    // the URL is not in a valid form
} catch (IOException e) {
    // the connection couldn't be established
}


And so, the main culprit was in my routes

file.

GET     /proxy/:url         controllers.Proxy.index(url:String) 
GET     /proxy               controllers.Proxy.index(url:String)

The first one caused an error. I replace it with query parameters as shown in the second line and everything worked out fine.

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