Fix creating arrays for constructor arguments

src/main/java/org/synyx/beanfiller/strategies/ArrayStrategy.java

@@ -72,9 +72,9 @@ public Object createObjectInternal(ObjectInformation objectInformation) throws F
     private <T> List<T> createObjectsForArray(Class<T> arrayType, Field field, int size,
         ObjectInformation parentObjectInformation) throws FillingException {
 
-        Type type = field.getGenericType();
+        Type type = field == null ? null : field.getGenericType();
 
-        if (GenericArrayType.class.isAssignableFrom(type.getClass())) {
+        if (type != null && GenericArrayType.class.isAssignableFrom(type.getClass())) {
             // if we have an Array of a Type with Generics, this is needed!
             type = ((GenericArrayType) type).getGenericComponentType();
         }

src/test/java/org/synyx/beanfiller/ConstructorCreationTest.java

@@ -0,0 +1,64 @@
+package org.synyx.beanfiller;
+
+import org.junit.Test;
+import org.synyx.beanfiller.exceptions.FillingException;
+import org.synyx.beanfiller.testobjects.TestEnum;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.notNullValue;
+
+public class ConstructorCreationTest {
+
+
+    @Test
+    public void createsObjectViaConstructor() throws FillingException {
+
+        TestObjectWithConstructor object = new BeanFiller().fillBean(TestObjectWithConstructor.class);
+
+        assertThat(object.array, notNullValue());
+        assertThat(object.array.length, greaterThan(0));
+        assertThat(object.testEnum, notNullValue());
+        assertThat(object.innerObject, notNullValue());
+        assertThat(object.innerObject.foo, notNullValue());
+    }
+
+    public static class TestObjectWithConstructor{
+
+        private final String[] array;
+        private final TestEnum testEnum;
+        private final InnerObject innerObject;
+
+        TestObjectWithConstructor(String[] array, TestEnum testEnum, InnerObject innerObject){
+
+            this.array = array;
+            this.testEnum = testEnum;
+            this.innerObject = innerObject;
+        }
+
+        public String[] getArray() {
+            return array;
+        }
+
+        public TestEnum getTestEnum() {
+            return testEnum;
+        }
+
+        public InnerObject getInnerObject() {
+            return innerObject;
+        }
+    }
+
+    public static class InnerObject{
+
+        private final String foo;
+
+        public InnerObject(String foo) {
+            this.foo = foo;
+        }
+
+        public String getFoo() {
+            return foo;
+        }
+    }
+}