Documentation

§Play WS Migration Guide

Play WS now has a standalone version - https://github.com/playframework/play-ws - that can be used outside a Play project. If you have a Play SBT project, you can still add WS by adding the following line to your build.sbt:

libraryDependencies += ws

This includes the play-ahc-ws module, which wraps the standalone version with Play Dependency Injection bindings and components, configuration and anything else that is necessary to better integrate it.

And if you want to use the cache support, you need to add ws, ehcache and enable and configure cache:

libraryDependencies += ws
libraryDependencies += ehcache

If you want to use it in a non Play project, it can be added to an SBT project with:

libraryDependencies += "com.typesafe.play" %% "play-ahc-ws-standalone" % "1.0.1"
libraryDependencies += "com.typesafe.play" %% "play-ws-standalone-json" % "1.0.1"
libraryDependencies += "com.typesafe.play" %% "play-ws-standalone-xml" % "1.0.1"

§Package changes

Play WS historically consisted of two libraries, ws and playWs, containing the Scala and Java APIs respectively, each individually creating an AsyncHTTPClient behind the scenes. There is now only one play-ahc-ws library, which contains both Scala and Java WSClient instances, and both point to a singleton AsyncHttpClient provider.

§Project changes

Play WS now exists as a Play specific wrapper on top of a standalone WS library, which does not depend on Play classes, and which uses package renamed “shaded” versions of AsyncHttpClient, Signpost, and Netty 4.0.

By providing a standalone WS version and using shaded libraries, WS is more flexible and has fewer collisions with other libraries and projects.

The Play WS API extends Standalone WS post with Http.Multipart and Multipart types that are only available in Play, for example:

def withBody(body: Source[MultipartFormData.Part[Source[ByteString, _]], _]): Self 

Signpost OAuth has been changed so that instead of using the Commons HTTPClient OAuthProvider, it now uses the DefaultOAuthProvider, which uses HTTPURLConnection under the hood.

§API changes

§Scala

The WSAPI class has been removed. The WSClient interface is the point of entry for the WS API.

WSRequest had a withBody[T](body: T)(implicit writable: play.api.http.Writable[T]) method has been replaced as it was difficult to track the behavior of Writable. There is now a custom BodyWritable[T] type class that fills the same function, and which has type class instances defined in Standalone WS:

override def withBody[T: BodyWritable](body: T)

The deprecated Scala singleton object play.api.libs.ws.WS has been removed. An instance of WSClient should be used instead. If compile time dependency injection is being used, then the AhcWSComponents trait should be mixed in.

For Guice, there is a WSClient available in the system:

class MyService @Inject()(ws: WSClient) {
   def call(): Unit = {     
     ws.url("http://localhost:9000/foo").get()
   }
}

If you cannot use an injected WSClient instance, then you can also create your own instance of WSClient, but you are then responsible for managing the lifecycle of the client.

If you are running a functional test, you can use the play.api.test.WsTestClient, which will start up and shut down a standalone WSClient instance:

play.api.test.WsTestClient.withClient { ws =>
  ws.url("http://localhost:9000/foo").get()
}

The ning package has been replaced by the ahc package, and the Ning* classes replaced by AHC*.

A normal WSResponse instance is returned from stream() instead of StreamedResponse. You should call response.bodyAsSource to return the streamed result.

There are some naming changes with deprecations to make things more explicit on play.api.libs.ws.WSRequest. Extra care should be exercised when migrating these:
- WsRequest.withHeaders is now WsRequest.addHttpHeaders (same behaviour) or WsRequest.withHttpHeaders (throws away existing headers)
- WsRequest.withQueryString is now WsRequest.addQueryStringParameters (same behaviour) or WsRequest.withQueryStringParameters (throws away existing query string)

§Java

In Java, the play.libs.ws.WS class has been deprecated. An injected WSClient instance should be used instead.

public class MyService {
     private final WSClient ws;

     @Inject
     public MyService(WSClient ws) {
         this.ws = ws;
     }

     public void call() {     
         ws.url("http://localhost:9000/foo").get();
     }
}

If you cannot use an injected WSClient instance, then you can also create your own instance of WSClient, but you are then responsible for managing the lifecycle of the client.

If you are running a functional test, you can use the play.test.WsTestClient, which will start up and shut down a standalone WSClient instance:

WSClient ws = play.test.WsTestClient.newClient(19001);
...
ws.close();

A normal WSResponse instance is returned from stream() instead of StreamedResponse. You should call response.getBodyAsSource() to return the streamed result.

Next: Cache Migration


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