启用Java的游戏框架的2.2.x CORS

Question

我有实现跨域在Java中播放的2.2.x的麻烦

在Java中，将其置于Global.java

public class Global extends GlobalSettings { 

    private class ActionWrapper extends Action.Simple { 
    public ActionWrapper(Action action) { 
    this.delegate = action; 
    } 

    @Override 
    public Result call(Http.Context ctx) throws java.lang.Throwable { 
     Result result = this.delegate.call(ctx); 
     Http.Response response = ctx.response(); 
     response.setHeader("Access-Control-Allow-Origin", "*"); 
     return result; 
    } 
    } 

    @Override 
    public Action onRequest(Http.Request request, java.lang.reflect.Method actionMethod) { 
    return new ActionWrapper(super.onRequest(request, actionMethod)); 
    } 

} 

播放2.1.3此代码的工作

但是，当我试图编译java的发挥2.2.x的，它不会再编译。

编译错误消息：

Global.ActionWrapper不是抽象的，不覆盖行动抽象方法调用（上下文）...

有没有为Java游戏2.2.x的任何等效代码？

谢谢。

Answer 1

它看起来像这样：

import play.GlobalSettings; 
import play.libs.F.Promise; 
import play.mvc.Action; 
import play.mvc.Http; 
import play.mvc.SimpleResult; 

public class Global extends GlobalSettings { 
    private class ActionWrapper extends Action.Simple { 
     public ActionWrapper(Action<?> action) { 
      this.delegate = action; 
     } 

     @Override 
     public Promise<SimpleResult> call(Http.Context ctx) throws java.lang.Throwable { 
      Promise<SimpleResult> result = this.delegate.call(ctx); 
      Http.Response response = ctx.response(); 
      response.setHeader("Access-Control-Allow-Origin", "*"); 
      return result; 
     } 
    } 

    @Override 
    public Action<?> onRequest(Http.Request request, java.lang.reflect.Method actionMethod) { 
     return new ActionWrapper(super.onRequest(request, actionMethod)); 
    } 
} 

Answer 2

对于使用2.3.1+（截至记者发稿）游戏的人来说，这是现在Promise<Result>而不是Promise<SimpleResult>

import play.GlobalSettings; 
import play.libs.F.Promise; 
import play.mvc.Action; 
import play.mvc.Http; 
import play.mvc.Result; 

public class Global extends GlobalSettings { 
    private class ActionWrapper extends Action.Simple { 
     public ActionWrapper(Action<?> action) { 
      this.delegate = action; 
     } 

     @Override 
     public Promise<Result> call(Http.Context ctx) throws java.lang.Throwable { 
      Promise<Result> result = this.delegate.call(ctx); 
      Http.Response response = ctx.response(); 
      response.setHeader("Access-Control-Allow-Origin", "*"); 
      return result; 
     } 
    } 

    @Override 
    public Action<?> onRequest(Http.Request request, java.lang.reflect.Method actionMethod) { 
     return new ActionWrapper(super.onRequest(request, actionMethod)); 
    } 
} 

Answer 3

另一种选择可能会使用Filters。目前只有Scala过滤器可用。然而，正如this post指出了简单地修改响应头，你可以复制粘贴&以下，使CORS着想。

package filters 

import play.api.mvc._ 
import play.mvc.Http.HeaderNames 
import scala.concurrent.Future 
import scala.concurrent.ExecutionContext.Implicits.global 

class EnableCORS extends Filter { 
    def apply(f: (RequestHeader) => Future[Result])(rh: RequestHeader): Future[Result] = { 
    val result = f(rh) 
    result.map(_.withHeaders(HeaderNames.ACCESS_CONTROL_ALLOW_ORIGIN -> "*")) 
    } 
} 

，然后在Global.java添加过滤器只是如此：

@Override 
public <T extends EssentialFilter> Class<T>[] filters() { 
    return new Class[] {EnableCORS.class}; 
} 

Answer 4

通过@alexhanschke提出的解决方案，因为过滤器是不是没有当请求抛出异常（内部服务器错误）工作，在发生这种情况时应用（请参阅https://github.com/playframework/playframework/issues/2429）。为了解决这个你得换一阶类并返回结果，如全图所示。请注意，这仍然需要指定选项路由和控制器来处理选项请求。

看到这里https://gist.github.com/tinusn/38c4c110f7cd1e1ec63f整个事情。

import static play.core.j.JavaResults.BadRequest; 
import static play.core.j.JavaResults.InternalServerError; 
import static play.core.j.JavaResults.NotFound; 

import java.util.ArrayList; 
import java.util.List; 

import play.GlobalSettings; 
import play.api.mvc.Results.Status; 
import play.libs.F.Promise; 
import play.libs.Scala; 
import play.mvc.Action; 
import play.mvc.Http; 
import play.mvc.Result; 
import scala.Tuple2; 
import scala.collection.Seq; 

public class Global extends GlobalSettings { 

    private class ActionWrapper extends Action.Simple { 
    public ActionWrapper(Action<?> action) { 
     this.delegate = action; 
    } 

    @Override 
    public Promise<Result> call(Http.Context ctx) throws java.lang.Throwable { 
     Promise<Result> result = this.delegate.call(ctx); 
     Http.Response response = ctx.response(); 
     response.setHeader("Access-Control-Allow-Origin", "*"); 
     return result; 
    } 
    } 

    /* 
    * Adds the required CORS header "Access-Control-Allow-Origin" to successfull requests 
    */ 
    @Override 
    public Action<?> onRequest(Http.Request request, java.lang.reflect.Method actionMethod) { 
    return new ActionWrapper(super.onRequest(request, actionMethod)); 
    } 

    private static class CORSResult implements Result { 
    final private play.api.mvc.Result wrappedResult; 

    public CORSResult(Status status) { 
     List<Tuple2<String, String>> list = new ArrayList<Tuple2<String, String>>(); 
     Tuple2<String, String> t = new Tuple2<String, String>("Access-Control-Allow-Origin","*"); 
     list.add(t); 
     Seq<Tuple2<String, String>> seq = Scala.toSeq(list); 
     wrappedResult = status.withHeaders(seq); 
    } 

    public play.api.mvc.Result toScala() { 
     return this.wrappedResult; 
    } 
    } 

    /* 
    * Adds the required CORS header "Access-Control-Allow-Origin" to bad requests 
    */ 
    @Override 
    public Promise<Result> onBadRequest(Http.RequestHeader request, String error) { 
    return Promise.<Result>pure(new CORSResult(BadRequest())); 
    } 

    /* 
    * Adds the required CORS header "Access-Control-Allow-Origin" to requests that causes an exception 
    */ 
    @Override 
    public Promise<Result> onError(Http.RequestHeader request, Throwable t) { 
    return Promise.<Result>pure(new CORSResult(InternalServerError())); 
    } 

    /* 
    * Adds the required CORS header "Access-Control-Allow-Origin" when a route was not found 
    */ 
    @Override 
    public Promise<Result> onHandlerNotFound(Http.RequestHeader request) { 
    return Promise.<Result>pure(new CORSResult(NotFound())); 
    } 

}