Fix generics in org.apache.commons.lang3.stream.Streams.toArray(Class)

signature

Author: garydgregory

src/changes/changes.xml

@@ -92,7 +92,8 @@ The <action> type attribute can be add,update,fix,remove.
     <action issue="LANG-1773" type="fix" dev="ggregory" due-to="Éamonn McManus, Gary Gregory">Apache Commons Lang no longer builds on Android #1381.</action>
     <action issue="LANG-1772" type="fix" dev="ggregory" due-to="James Winters, Piotr P. Karwasz, Gary Gregory">Restrict size of cache to prevent overflow errors #1379.</action>
     <action issue="LANG-1772" type="fix" dev="ggregory" due-to="Gary Gregory">Reimplement org.apache.commons.lang3.ClassUtils.hierarchy(Class, Interfaces) using an AtomicReference.</action>
-    <action                   type="fix" dev="ggregory" due-to="Ken Dombeck">Correct Javadoc code examples in DiffBuilder and ReflectionDiffBuilder #1400.</action>
+    <action                   type="fix" dev="ggregory" due-to="Ken Dombeck">Fix Javadoc code examples in DiffBuilder and ReflectionDiffBuilder #1400.</action>
+    <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Fix generics in org.apache.commons.lang3.stream.Streams.toArray(Class) signature.</action>
     <!-- ADD -->
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add Strings and refactor StringUtils.</action>
     <action issue="LANG-1747" type="add" dev="ggregory" due-to="Oliver B. Fischer, Gary Gregory">Add StopWatch.run([Failable]Runnable) and get([Failable]Supplier).</action>

src/main/java/org/apache/commons/lang3/stream/Streams.java

@@ -838,7 +838,7 @@ private static <T> Stream<T> streamOf(final T value) {
      * @param elementType Type of an element in the array.
      * @return a {@link Collector} which collects all the input elements into an array, in encounter order
      */
-    public static <T> Collector<T, ?, T[]> toArray(final Class<T> elementType) {
+    public static <T> Collector<T, List<T>, T[]> toArray(final Class<T> elementType) {
         return new ArrayCollector<>(elementType);
     }
 

src/test/java/org/apache/commons/lang3/stream/StreamsTest.java

@@ -16,6 +16,7 @@
  */
 package org.apache.commons.lang3.stream;
 
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
@@ -125,6 +126,16 @@ public Stream<DynamicTest> simpleStreamForEachFailing() {
             }));
     }
 
+    @Test
+    void testArrayCollectorCombiner() {
+        final String[] expected = { "A1", "B1" };
+        assertArrayEquals(expected, Stream.of("A", "B").collect(Collectors.mapping(s -> s + "1", Streams.toArray(String.class))));
+        assertArrayEquals(expected, Streams.failableStream("A", "B").collect(Collectors.mapping(s -> s + "1", Streams.toArray(String.class))));
+        final List<String> left = new ArrayList<>();
+        left.add("a");
+        assertEquals(Arrays.asList("a", "b", "c"), Streams.toArray(String.class).combiner().apply(left, Arrays.asList("b", "c")));
+    }
+
     @SuppressWarnings("deprecation")
     @Test
     void testDeprefcatedCopnstructor() {