content.java

/**
 * Copyright (C) 2014 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.stream.javadsl.japi;

import akka.stream.javadsl.MaterializedDrain;
import org.reactivestreams.Subscriber;

import java.util.concurrent.Future;

public class JavaPain {
  {
    Materialized materialized = new Materialized();

    DrainWithTheKey<Object, Subscriber<Long>> drainKey = new DrainWithTheKey<Object, Subscriber<Long>>();

    Subscriber<Long> drainFor = materialized.getDrainFor(drainKey);

    Future<String> future1 = materialized.getDrainFor(new DrainWithTheKey<Object, Future<String>>());

    FoldDrain<String, Future<String>> foldDrain = new FoldDrain<String, Future<String>>();
    Future<String> future2 = materialized.getDrainFor(foldDrain);
  }
}

class FoldDrain<U, In> extends DrainWithTheKey<In, Future<In>> { }

class DrainWithTheKey<A, Type> {
  public Type value() { return null; }
}

class Materialized {
  public <T> T getDrainFor(DrainWithTheKey<Object, T> drainKey) { return drainKey.value(); }
}