Merge branch 'LANG-1402' of https://github.com/MarkDacek/commons-lang

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

@@ -8672,4 +8672,20 @@ public class ArrayUtils {
             swap(array, i - 1, random.nextInt(i), 1);
         }
     }
+
+    /**
+     * Returns whether a given array can safely be accessed at the given index.
+     * @param <T> the component type of the array
+     * @param array the array to inspect, may be null
+     * @param index the index of the array to be inspected
+     * @return Whether the given index is safely-accessible in the given array
+     * @since 3.8
+     */
+    public static <T> boolean isArrayIndexValid(T[] array, int index){
+        if(getLength(array) == 0 || array.length <= index){
+            return false;
+        }
+
+        return index >= 0;
+    }
 }

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

@@ -5111,4 +5111,19 @@ public class ArrayUtilsTest {
             assertTrue("Element " + element + " not found", ArrayUtils.contains(array1, element));
         }
     }
+
+    @Test
+    public void testIsArrayIndexValid(){
+        assertFalse(ArrayUtils.isArrayIndexValid(null, 0));
+        String[] array = new String[1];
+
+        //too big
+        assertFalse(ArrayUtils.isArrayIndexValid(array, 1));
+
+        //negative index
+        assertFalse(ArrayUtils.isArrayIndexValid(array, -1));
+
+        //good to go
+        assertTrue(ArrayUtils.isArrayIndexValid(array, 0));
+    }
 }