Finisher can't be null anymore

mgevantmakher · Mar 22, 2019 · aa12b5d · aa12b5d
1 parent 8b50795
commit aa12b5d
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Showing 2 changed files with 22 additions and 31 deletions.
diff --git a/stream/src/main/java/com/annimon/stream/Collectors.java b/stream/src/main/java/com/annimon/stream/Collectors.java
@@ -875,13 +875,12 @@ public void accept(U u) {
      */
     @NotNull
     public static <T, A, IR, OR> Collector<T, A, OR> collectingAndThen(
-            @NotNull Collector<T, A, IR> c, Function<IR, OR> finisher) {
-        Function<A, IR> downstreamFinisher = c.finisher();
-        if (downstreamFinisher == null) {
-            downstreamFinisher = castIdentity();
-        }
+            @NotNull Collector<T, A, IR> c,
+            @NotNull Function<IR, OR> finisher) {
+        Objects.requireNonNull(c);
+        Objects.requireNonNull(finisher);
         return new CollectorsImpl<T, A, OR>(c.supplier(), c.accumulator(),
-                Function.Util.andThen(downstreamFinisher, finisher));
+                Function.Util.andThen(c.finisher(), finisher));
     }
 
     /**
@@ -944,24 +943,21 @@ public static <T, A, IR, OR> Collector<T, A, OR> collectingAndThen(
 
         @SuppressWarnings("unchecked")
         final Function<A, A> downstreamFinisher = (Function<A, A>) downstream.finisher();
-        Function<Map<K, A>, M> finisher = null;
-        if (downstreamFinisher != null) {
-            finisher = new Function<Map<K, A>, M>() {
-                @NotNull
-                @Override
-                public M apply(@NotNull Map<K, A> map) {
-                    // Update values of a map by a finisher function
-                    for (Map.Entry<K, A> entry : map.entrySet()) {
-                        A value = entry.getValue();
-                        value = downstreamFinisher.apply(value);
-                        entry.setValue(value);
-                    }
-                    @SuppressWarnings("unchecked")
-                    M castedMap = (M) map;
-                    return castedMap;
+        Function<Map<K, A>, M> finisher = new Function<Map<K, A>, M>() {
+            @NotNull
+            @Override
+            public M apply(@NotNull Map<K, A> map) {
+                // Update values of a map by a finisher function
+                for (Map.Entry<K, A> entry : map.entrySet()) {
+                    A value = entry.getValue();
+                    value = downstreamFinisher.apply(value);
+                    entry.setValue(value);
                 }
-            };
-        }
+                @SuppressWarnings("unchecked")
+                M castedMap = (M) map;
+                return castedMap;
+            }
+        };
 
         @SuppressWarnings("unchecked")
         Supplier<Map<K, A>> castedMapFactory = (Supplier<Map<K, A>>) mapFactory;
@@ -1042,10 +1038,7 @@ public void accept(@NotNull Tuple2<A> container, T t) {
                     @NotNull
                     @Override
                     public Map<Boolean, D> apply(@NotNull Tuple2<A> container) {
-                        final Function<A, D> downstreamFinisher = downstream.finisher();
-                        final Function<A, D> finisher = downstreamFinisher == null
-                                ? Collectors.<A, D>castIdentity()
-                                : downstreamFinisher;
+                        final Function<A, D> finisher = downstream.finisher();
                         Map<Boolean, D> result = new HashMap<Boolean, D>(2);
                         result.put(Boolean.TRUE, finisher.apply(container.a));
                         result.put(Boolean.FALSE, finisher.apply(container.b));
@@ -1218,7 +1211,7 @@ private static final class CollectorsImpl<T, A, R> implements Collector<T, A, R>
         private final Function<A, R> finisher;
 
         public CollectorsImpl(Supplier<A> supplier, BiConsumer<A, T> accumulator) {
-            this(supplier, accumulator, null);
+            this(supplier, accumulator, Collectors.<A, R>castIdentity());
         }
 
         public CollectorsImpl(Supplier<A> supplier, BiConsumer<A, T> accumulator, Function<A, R> finisher) {

diff --git a/stream/src/main/java/com/annimon/stream/Stream.java b/stream/src/main/java/com/annimon/stream/Stream.java
@@ -1825,9 +1825,7 @@ public <R, A> R collect(@NotNull Collector<? super T, A, R> collector) {
             final T value = iterator.next();
             collector.accumulator().accept(container, value);
         }
-        if (collector.finisher() != null)
-            return collector.finisher().apply(container);
-        return Collectors.<A, R>castIdentity().apply(container);
+        return collector.finisher().apply(container);
     }
 
     /**