use method reference

core/play-java/src/test/java/play/mvc/HttpTest.java

@@ -173,7 +173,7 @@ public void testSetTransientLangFailure() {
           // When trying to get the messages it does not work because en-NZ is not valid
           assertThat(messagesApi(app).preferred(req).lang().code()).isEqualTo("en");
           // However if you access the transient lang directly you will see it was set
-          assertThat(req.transientLang().map(l -> l.code())).isEqualTo(Optional.of("en-NZ"));
+          assertThat(req.transientLang().map(Lang::code)).isEqualTo(Optional.of("en-NZ"));
         });
   }
 
@@ -228,11 +228,11 @@ public void testRequestImplLang() {
 
           // Make sure the new request correctly set its internal lang variable
           assertThat(messagesApi(app).preferred(newReq).lang().code()).isEqualTo("en-US");
-          assertThat(newReq.transientLang().map(l -> l.code())).isEqualTo(Optional.of("en-US"));
+          assertThat(newReq.transientLang().map(Lang::code)).isEqualTo(Optional.of("en-US"));
 
           // Also make sure the original request didn't change it's language
           assertThat(messagesApi(app).preferred(req).lang().code()).isEqualTo("fr");
-          assertThat(req.transientLang().map(l -> l.code())).isEqualTo(Optional.of("fr"));
+          assertThat(req.transientLang().map(Lang::code)).isEqualTo(Optional.of("fr"));
         });
   }
 }

core/play-java/src/test/java/play/mvc/RequestBuilderTest.java

@@ -242,7 +242,7 @@ public void testAddALangCookieToRequestBuilder() {
 
     assertEquals(
         Optional.of(lang.code()),
-        request.getCookie(Helpers.stubMessagesApi().langCookieName()).map(c -> c.value()));
+        request.getCookie(Helpers.stubMessagesApi().langCookieName()).map(Http.Cookie::value));
     assertFalse(request.transientLang().isPresent());
     assertFalse(request.attrs().getOptional(Messages.Attrs.CurrentLang).isPresent());
   }
@@ -256,7 +256,7 @@ public void testAddALangCookieByLocaleToRequestBuilder() {
 
     assertEquals(
         Optional.of(locale.toLanguageTag()),
-        request.getCookie(Helpers.stubMessagesApi().langCookieName()).map(c -> c.value()));
+        request.getCookie(Helpers.stubMessagesApi().langCookieName()).map(Http.Cookie::value));
     assertFalse(request.transientLang().isPresent());
     assertFalse(request.attrs().getOptional(Messages.Attrs.CurrentLang).isPresent());
   }

core/play-streams/src/test/java/play/libs/streams/AccumulatorTest.java

@@ -26,7 +26,7 @@ public class AccumulatorTest {
   private Executor ec;
 
   private Accumulator<Integer, Integer> sum =
-      Accumulator.fromSink(Sink.<Integer, Integer>fold(0, (a, b) -> a + b));
+      Accumulator.fromSink(Sink.<Integer, Integer>fold(0, Integer::sum));
   private Source<Integer, ?> source = Source.from(Arrays.asList(1, 2, 3));
 
   private <T> T await(CompletionStage<T> cs) throws Exception {

core/play/src/main/java/play/http/DefaultHttpFilters.java

@@ -23,7 +23,8 @@ public DefaultHttpFilters(play.api.mvc.EssentialFilter... filters) {
   }
 
   public DefaultHttpFilters(List<? extends play.api.mvc.EssentialFilter> filters) {
-    this.filters = filters.stream().map(f -> f.asJava()).collect(Collectors.toList());
+    this.filters =
+        filters.stream().map(play.api.mvc.EssentialFilter::asJava).collect(Collectors.toList());
   }
 
   @Override

core/play/src/main/java/play/mvc/Result.java

@@ -534,7 +534,7 @@ public Result discardingCookie(
                 path,
                 Option.apply(domain),
                 secure,
-                Option.apply(sameSite).map(ss -> ss.asScala()))
+                Option.apply(sameSite).map(Cookie.SameSite::asScala))
             .toCookie()
             .asJava());
   }

core/play/src/main/java/play/mvc/StatusHeader.java

@@ -1445,7 +1445,7 @@ public Result sendFile(
     return sendFile(
         file,
         inline,
-        Optional.ofNullable(file).map(f -> f.getName()),
+        Optional.ofNullable(file).map(File::getName),
         fileMimeTypes,
         onClose,
         executor);
@@ -1943,9 +1943,6 @@ public Result sendEntity(
     return new Result(
         status(),
         Results.contentDispositionHeader(inline, fileName),
-        entity.as(
-            fileName
-                .flatMap(name -> fileMimeTypes.forFileName(name))
-                .orElse(Http.MimeTypes.BINARY)));
+        entity.as(fileName.flatMap(fileMimeTypes::forFileName).orElse(Http.MimeTypes.BINARY)));
   }
 }

web/play-filters-helpers/src/main/java/play/filters/csrf/AddCSRFTokenAction.java

@@ -10,6 +10,7 @@
 
 import play.api.http.SessionConfiguration;
 import play.api.libs.crypto.CSRFTokenSigner;
+import play.api.mvc.Cookie;
 import play.mvc.Action;
 import play.mvc.Http;
 import play.mvc.Http.RequestBody;
@@ -74,7 +75,9 @@ private Result placeToken(Http.Request req, final Result result, CSRF.Token toke
               domain.isDefined() ? domain.get() : null,
               config.secureCookie(),
               config.httpOnlyCookie(),
-              OptionConverters.toJava(config.sameSiteCookie()).map(c -> c.asJava()).orElse(null));
+              OptionConverters.toJava(config.sameSiteCookie())
+                  .map(Cookie.SameSite::asJava)
+                  .orElse(null));
       return result.withCookies(cookie);
     }
     return result.addingToSession(req, token.name(), token.value());

web/play-java-forms/src/main/java/play/data/DynamicForm.java

@@ -223,14 +223,14 @@ public Optional<Object> value(String key) {
   public Map<String, String> rawData() {
     return Collections.unmodifiableMap(
         super.rawData().entrySet().stream()
-            .collect(Collectors.toMap(e -> asNormalKey(e.getKey()), e -> e.getValue())));
+            .collect(Collectors.toMap(e -> asNormalKey(e.getKey()), Map.Entry::getValue)));
   }
 
   @Override
   public Map<String, Http.MultipartFormData.FilePart<?>> files() {
     return Collections.unmodifiableMap(
         super.files().entrySet().stream()
-            .collect(Collectors.toMap(e -> asNormalKey(e.getKey()), e -> e.getValue())));
+            .collect(Collectors.toMap(e -> asNormalKey(e.getKey()), Map.Entry::getValue)));
   }
 
   /**
@@ -316,9 +316,9 @@ public DynamicForm bind(
             lang,
             attrs,
             data.entrySet().stream()
-                .collect(Collectors.toMap(e -> asDynamicKey(e.getKey()), e -> e.getValue())),
+                .collect(Collectors.toMap(e -> asDynamicKey(e.getKey()), Map.Entry::getValue)),
             files.entrySet().stream()
-                .collect(Collectors.toMap(e -> asDynamicKey(e.getKey()), e -> e.getValue())),
+                .collect(Collectors.toMap(e -> asDynamicKey(e.getKey()), Map.Entry::getValue)),
             allowedFields);
     return new DynamicForm(
         form.rawData(),

web/play-java-forms/src/main/java/play/data/Form.java

@@ -646,7 +646,7 @@ protected <A> Map<String, Http.MultipartFormData.FilePart<?>> resolveDuplicateFi
                     }));
     final Map<String, Http.MultipartFormData.FilePart<?>> data = new HashMap<>();
     resolvedDuplicateKeys.forEach(
-        (key, values) -> fillDataWith(key, data, values.size(), i -> values.get(i)));
+        (key, values) -> fillDataWith(key, data, values.size(), values::get));
     return data;
   }
 

web/play-java-forms/src/main/java/play/data/validation/Constraints.java

@@ -138,7 +138,7 @@ public static List<Tuple<String, List<Object>>> displayableConstraint(
     return constraints
         .parallelStream()
         .filter(c -> c.getAnnotation().annotationType().isAnnotationPresent(Display.class))
-        .map(c -> displayableConstraint(c))
+        .map(Constraints::displayableConstraint)
         .collect(Collectors.toList());
   }
 
@@ -155,7 +155,9 @@ public static List<Tuple<String, List<Object>>> displayableConstraint(
   public static List<Tuple<String, List<Object>>> displayableConstraint(
       Set<ConstraintDescriptor<?>> constraints, Annotation[] orderedAnnotations) {
     final List<Annotation> constraintAnnot =
-        constraints.stream().map(c -> c.getAnnotation()).collect(Collectors.<Annotation>toList());
+        constraints.stream()
+            .map(ConstraintDescriptor::getAnnotation)
+            .collect(Collectors.<Annotation>toList());
 
     return Stream.of(orderedAnnotations)
         .filter(