Fix NPE in ArrayUtils.toStringArray() when array contains nulls

src/main/java/org/apache/commons/lang3/ArrayUtils.java

@@ -60,6 +60,38 @@
  */
 public class ArrayUtils {
 
+    /**
+ * Converts an array of objects to an array of strings, using {@code "null"} to represent {@code null} elements.
+ *
+ * @param array the array of objects to convert, may be {@code null}
+ * @return a string array, {@code null} if input is {@code null}
+ */
+public static String[] toStringArray(final Object[] array) {
+    return toStringArray(array, "null");
+}
+
+/**
+ * Converts an array of objects to an array of strings, using the provided
+ * {@code nullReplacement} to represent {@code null} elements.
+ *
+ * @param array the array of objects to convert, may be {@code null}
+ * @param nullReplacement the string to use for {@code null} elements
+ * @return a string array, {@code null} if input is {@code null}
+ */
+public static String[] toStringArray(final Object[] array, final String nullReplacement) {
+    if (array == null) {
+        return null;
+    }
+    final String[] result = new String[array.length];
+    for (int i = 0; i < array.length; i++) {
+        result[i] = array[i] == null ? nullReplacement : array[i].toString();
+    }
+    return result;
+}
+
+
+
+
     /**
      * An empty immutable {@code boolean} array.
      */
@@ -9536,9 +9568,8 @@ public static String toString(final Object array, final String stringIfNull) {
      * {@code null} if null array input
      * @since 3.6
      */
-    public static String[] toStringArray(final Object[] array) {
-        return toStringArray(array, "null");
-    }
+    /**
+
 
     /**
      * Returns an array containing the string representation of each element in the argument
@@ -9552,15 +9583,8 @@ public static String[] toStringArray(final Object[] array) {
      * @return a {@link String} array, {@code null} if null array input
      * @since 3.6
      */
-    public static String[] toStringArray(final Object[] array, final String valueForNullElements) {
-        if (null == array) {
-            return null;
-        }
-        if (array.length == 0) {
-            return EMPTY_STRING_ARRAY;
-        }
-        return map(array, String.class, e -> Objects.toString(e, valueForNullElements));
-    }
+
+
 
     /**
      * ArrayUtils instances should NOT be constructed in standard programming.

src/test/java/org/apache/commons/lang3/ArrayUtilsTest.java

@@ -90,6 +90,14 @@ void testArraycopyFunction() {
         assertNullPointerException(() -> ArrayUtils.arraycopy(arr, 0, 0, 1, (Function<Integer, String[]>) null));
     }
 
+    @Test
+public void testToStringArrayHandlesNullElements() {
+    Object[] input = { "apple", null, 42 };
+    String[] result = ArrayUtils.toStringArray(input);
+
+    assertArrayEquals(new String[] { "apple", "null", "42" }, result);
+}
+
     @Test
     void testArraycopySupplier() {
         final String[] arr = { "a", "b" };