diff --git a/akka-stream-tests/src/test/java/akka/stream/javadsl/FlowTest.java b/akka-stream-tests/src/test/java/akka/stream/javadsl/FlowTest.java
index 0176b5980d..f4c8eb908a 100644
--- a/akka-stream-tests/src/test/java/akka/stream/javadsl/FlowTest.java
+++ b/akka-stream-tests/src/test/java/akka/stream/javadsl/FlowTest.java
@@ -308,7 +308,7 @@ public class FlowTest extends StreamTest {
             .mergeSubstreams();
 
     final CompletionStage<List<List<String>>> future =
-        Source.from(input).via(flow).limit(10).runWith(Sink.<List<String>>seq(), system);
+        Source.from(input).via(flow).limit(10).runWith(Sink.seq(), system);
     final Object[] result = future.toCompletableFuture().get(1, TimeUnit.SECONDS).toArray();
     Arrays.sort(
         result,
@@ -343,7 +343,7 @@ public class FlowTest extends StreamTest {
             .concatSubstreams();
 
     final CompletionStage<List<List<String>>> future =
-        Source.from(input).via(flow).limit(10).runWith(Sink.<List<String>>seq(), system);
+        Source.from(input).via(flow).limit(10).runWith(Sink.seq(), system);
     final List<List<String>> result = future.toCompletableFuture().get(1, TimeUnit.SECONDS);
 
     assertEquals(
@@ -367,7 +367,7 @@ public class FlowTest extends StreamTest {
             .concatSubstreams();
 
     final CompletionStage<List<List<String>>> future =
-        Source.from(input).via(flow).limit(10).runWith(Sink.<List<String>>seq(), system);
+        Source.from(input).via(flow).limit(10).runWith(Sink.seq(), system);
     final List<List<String>> result = future.toCompletableFuture().get(1, TimeUnit.SECONDS);
 
     assertEquals(
@@ -433,35 +433,34 @@ public class FlowTest extends StreamTest {
                 new Function<GraphDSL.Builder<NotUsed>, SourceShape<String>>() {
                   @Override
                   public SourceShape<String> apply(Builder<NotUsed> b) throws Exception {
-                    final UniformFanInShape<String, String> merge = b.add(Merge.<String>create(2));
+                    final UniformFanInShape<String, String> merge = b.add(Merge.create(2));
                     b.from(b.add(in1)).via(b.add(f1)).toInlet(merge.in(0));
                     b.from(b.add(in2)).via(b.add(f2)).toInlet(merge.in(1));
-                    return new SourceShape<String>(merge.out());
+                    return new SourceShape<>(merge.out());
                   }
                 }));
 
     // collecting
     final Publisher<String> pub = source.runWith(publisher, system);
     final CompletionStage<List<String>> all =
-        Source.fromPublisher(pub).limit(100).runWith(Sink.<String>seq(), system);
+        Source.fromPublisher(pub).limit(100).runWith(Sink.seq(), system);
 
     final List<String> result = all.toCompletableFuture().get(3, TimeUnit.SECONDS);
     assertEquals(
-        new HashSet<Object>(Arrays.asList("a", "b", "c", "d", "e", "f")),
-        new HashSet<String>(result));
+        new HashSet<Object>(Arrays.asList("a", "b", "c", "d", "e", "f")), new HashSet<>(result));
   }
 
   @Test
   public void mustBeAbleToUsefromSourceCompletionStage() throws Exception {
     final Flow<String, String, NotUsed> f1 =
-        Flow.of(String.class).via(FlowTest.this.<String>op()).named("f1");
+        Flow.of(String.class).via(FlowTest.this.op()).named("f1");
 
     final Flow<String, String, NotUsed> f2 =
-        Flow.of(String.class).via(FlowTest.this.<String>op()).named("f2");
+        Flow.of(String.class).via(FlowTest.this.op()).named("f2");
 
     @SuppressWarnings("unused")
     final Flow<String, String, NotUsed> f3 =
-        Flow.of(String.class).via(FlowTest.this.<String>op()).named("f3");
+        Flow.of(String.class).via(FlowTest.this.op()).named("f3");
 
     final Source<String, NotUsed> in1 = Source.from(Arrays.asList("a", "b", "c"));
     final Source<String, NotUsed> in2 = Source.from(Arrays.asList("d", "e", "f"));
@@ -474,10 +473,10 @@ public class FlowTest extends StreamTest {
                 new Function<GraphDSL.Builder<NotUsed>, SourceShape<String>>() {
                   @Override
                   public SourceShape<String> apply(Builder<NotUsed> b) throws Exception {
-                    final UniformFanInShape<String, String> merge = b.add(Merge.<String>create(2));
+                    final UniformFanInShape<String, String> merge = b.add(Merge.create(2));
                     b.from(b.add(in1)).via(b.add(f1)).toInlet(merge.in(0));
                     b.from(b.add(in2)).via(b.add(f2)).toInlet(merge.in(1));
-                    return new SourceShape<String>(merge.out());
+                    return new SourceShape<>(merge.out());
                   }
                 }));
 
@@ -497,12 +496,11 @@ public class FlowTest extends StreamTest {
     // collecting
     final Publisher<String> pub = source.runWith(publisher, system);
     final CompletionStage<List<String>> all =
-        Source.fromPublisher(pub).limit(100).runWith(Sink.<String>seq(), system);
+        Source.fromPublisher(pub).limit(100).runWith(Sink.seq(), system);
 
     final List<String> result = all.toCompletableFuture().get(3, TimeUnit.SECONDS);
     assertEquals(
-        new HashSet<Object>(Arrays.asList("a", "b", "c", "d", "e", "f")),
-        new HashSet<String>(result));
+        new HashSet<Object>(Arrays.asList("a", "b", "c", "d", "e", "f")), new HashSet<>(result));
   }
 
   @Test
@@ -518,7 +516,7 @@ public class FlowTest extends StreamTest {
                     final Outlet<String> in1 = b.add(Source.from(input1)).out();
                     final Outlet<Integer> in2 = b.add(Source.from(input2)).out();
                     final FanInShape2<String, Integer, Pair<String, Integer>> zip =
-                        b.add(Zip.<String, Integer>create());
+                        b.add(Zip.create());
                     final SinkShape<Pair<String, Integer>> out =
                         b.add(
                             Sink.foreach(
@@ -539,10 +537,7 @@ public class FlowTest extends StreamTest {
 
     List<Object> output = probe.receiveN(3);
     List<Pair<String, Integer>> expected =
-        Arrays.asList(
-            new Pair<String, Integer>("A", 1),
-            new Pair<String, Integer>("B", 2),
-            new Pair<String, Integer>("C", 3));
+        Arrays.asList(new Pair<>("A", 1), new Pair<>("B", 2), new Pair<>("C", 3));
     assertEquals(expected, output);
   }
 
@@ -569,10 +564,7 @@ public class FlowTest extends StreamTest {
     List<Object> output = probe.receiveN(4);
     List<Pair<String, Integer>> expected =
         Arrays.asList(
-            new Pair<String, Integer>("A", 1),
-            new Pair<String, Integer>("B", 2),
-            new Pair<String, Integer>("C", 3),
-            new Pair<String, Integer>("MISSING", 4));
+            new Pair<>("A", 1), new Pair<>("B", 2), new Pair<>("C", 3), new Pair<>("MISSING", 4));
     assertEquals(expected, output);
   }
 
@@ -627,15 +619,13 @@ public class FlowTest extends StreamTest {
     final Flow<Integer, Pair<List<Integer>, Source<Integer, NotUsed>>, NotUsed> flow =
         Flow.of(Integer.class).prefixAndTail(3);
     CompletionStage<Pair<List<Integer>, Source<Integer, NotUsed>>> future =
-        Source.from(input)
-            .via(flow)
-            .runWith(Sink.<Pair<List<Integer>, Source<Integer, NotUsed>>>head(), system);
+        Source.from(input).via(flow).runWith(Sink.head(), system);
     Pair<List<Integer>, Source<Integer, NotUsed>> result =
         future.toCompletableFuture().get(3, TimeUnit.SECONDS);
     assertEquals(Arrays.asList(1, 2, 3), result.first());
 
     CompletionStage<List<Integer>> tailFuture =
-        result.second().limit(4).runWith(Sink.<Integer>seq(), system);
+        result.second().limit(4).runWith(Sink.seq(), system);
     List<Integer> tailResult = tailFuture.toCompletableFuture().get(3, TimeUnit.SECONDS);
     assertEquals(Arrays.asList(4, 5, 6), tailResult);
   }
@@ -646,16 +636,16 @@ public class FlowTest extends StreamTest {
     final Iterable<Integer> input1 = Arrays.asList(1, 2, 3);
     final Iterable<Integer> input2 = Arrays.asList(4, 5);
 
-    final List<Source<Integer, NotUsed>> mainInputs = new ArrayList<Source<Integer, NotUsed>>();
+    final List<Source<Integer, NotUsed>> mainInputs = new ArrayList<>();
     mainInputs.add(Source.from(input1));
     mainInputs.add(Source.from(input2));
 
     final Flow<Source<Integer, NotUsed>, List<Integer>, NotUsed> flow =
         Flow.<Source<Integer, NotUsed>>create()
-            .flatMapConcat(ConstantFun.<Source<Integer, NotUsed>>javaIdentityFunction())
+            .flatMapConcat(ConstantFun.javaIdentityFunction())
             .grouped(6);
     CompletionStage<List<Integer>> future =
-        Source.from(mainInputs).via(flow).runWith(Sink.<List<Integer>>head(), system);
+        Source.from(mainInputs).via(flow).runWith(Sink.head(), system);
 
     List<Integer> result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
 
@@ -670,7 +660,7 @@ public class FlowTest extends StreamTest {
     final Iterable<Integer> input3 = Arrays.asList(20, 21, 22, 23, 24, 25, 26, 27, 28, 29);
     final Iterable<Integer> input4 = Arrays.asList(30, 31, 32, 33, 34, 35, 36, 37, 38, 39);
 
-    final List<Source<Integer, NotUsed>> mainInputs = new ArrayList<Source<Integer, NotUsed>>();
+    final List<Source<Integer, NotUsed>> mainInputs = new ArrayList<>();
     mainInputs.add(Source.from(input1));
     mainInputs.add(Source.from(input2));
     mainInputs.add(Source.from(input3));
@@ -678,17 +668,17 @@ public class FlowTest extends StreamTest {
 
     final Flow<Source<Integer, NotUsed>, List<Integer>, NotUsed> flow =
         Flow.<Source<Integer, NotUsed>>create()
-            .flatMapMerge(3, ConstantFun.<Source<Integer, NotUsed>>javaIdentityFunction())
+            .flatMapMerge(3, ConstantFun.javaIdentityFunction())
             .grouped(60);
     CompletionStage<List<Integer>> future =
-        Source.from(mainInputs).via(flow).runWith(Sink.<List<Integer>>head(), system);
+        Source.from(mainInputs).via(flow).runWith(Sink.head(), system);
 
     List<Integer> result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
-    final Set<Integer> set = new HashSet<Integer>();
+    final Set<Integer> set = new HashSet<>();
     for (Integer i : result) {
       set.add(i);
     }
-    final Set<Integer> expected = new HashSet<Integer>();
+    final Set<Integer> expected = new HashSet<>();
     for (int i = 0; i < 40; ++i) {
       expected.add(i);
     }
@@ -703,7 +693,7 @@ public class FlowTest extends StreamTest {
     final Flow<String, List<String>, NotUsed> flow =
         Flow.of(String.class).buffer(2, OverflowStrategy.backpressure()).grouped(4);
     final CompletionStage<List<String>> future =
-        Source.from(input).via(flow).runWith(Sink.<List<String>>head(), system);
+        Source.from(input).via(flow).runWith(Sink.head(), system);
 
     List<String> result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
     assertEquals(input, result);
@@ -814,7 +804,7 @@ public class FlowTest extends StreamTest {
     final List<String> input = Arrays.asList("A", "B", "C");
     final Flow<String, String, NotUsed> flow =
         Flow.of(String.class).expand(in -> Stream.iterate(in, i -> i).iterator());
-    final Sink<String, CompletionStage<String>> sink = Sink.<String>head();
+    final Sink<String, CompletionStage<String>> sink = Sink.head();
     CompletionStage<String> future = Source.from(input).via(flow).runWith(sink, system);
     String result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
     assertEquals("A", result);
@@ -1187,23 +1177,20 @@ public class FlowTest extends StreamTest {
                   @Override
                   public SinkShape<String> apply(Builder<NotUsed> b) throws Exception {
                     final UniformFanOutShape<String, String> broadcast =
-                        b.add(Broadcast.<String>create(2, true));
-                    final SinkShape<String> out1 = b.add(Sink.<String>cancelled());
-                    final SinkShape<String> out2 = b.add(Sink.<String>ignore());
+                        b.add(Broadcast.create(2, true));
+                    final SinkShape<String> out1 = b.add(Sink.cancelled());
+                    final SinkShape<String> out2 = b.add(Sink.ignore());
                     b.from(broadcast.out(0)).to(out1);
                     b.from(broadcast.out(1)).to(out2);
-                    return new SinkShape<String>(broadcast.in());
+                    return new SinkShape<>(broadcast.in());
                   }
                 }));
 
     final TestKit probe = new TestKit(system);
     Source<String, ActorRef> source =
         Source.actorRef(
-            msg -> Optional.<CompletionStrategy>empty(),
-            msg -> Optional.<Throwable>empty(),
-            1,
-            OverflowStrategy.dropNew());
-    final ActorRef actor = source.toMat(sink, Keep.<ActorRef, NotUsed>left()).run(system);
+            msg -> Optional.empty(), msg -> Optional.empty(), 1, OverflowStrategy.dropNew());
+    final ActorRef actor = source.toMat(sink, Keep.left()).run(system);
     probe.watch(actor);
     probe.expectTerminated(actor);
   }
@@ -1253,9 +1240,9 @@ public class FlowTest extends StreamTest {
             },
             system);
 
-    probe.expectMsgEquals(new Pair<String, String>("A", "D"));
-    probe.expectMsgEquals(new Pair<String, String>("B", "E"));
-    probe.expectMsgEquals(new Pair<String, String>("C", "F"));
+    probe.expectMsgEquals(new Pair<>("A", "D"));
+    probe.expectMsgEquals(new Pair<>("B", "E"));
+    probe.expectMsgEquals(new Pair<>("C", "F"));
   }
 
   @Test