Fix possible ClassCastException and cleanup warnings in NoRequestMappingAnnotation

Author: sambsnyd

src/main/java/org/openrewrite/java/spring/NoRequestMappingAnnotation.java

@@ -92,19 +92,17 @@ public J.Annotation visitAnnotation(J.Annotation annotation, ExecutionContext ct
                 requestType.ifPresent(requestMethod -> maybeRemoveImport("org.springframework.web.bind.annotation.RequestMethod." + requestMethod));
 
                 // Remove the argument
-                if (requestMethodArg.isPresent() && methodArgumentHasSingleType(requestMethodArg.get()) && resolvedRequestMappingAnnotationClassName != null) {
+                if (methodArgumentHasSingleType(requestMethodArg.get())) {
                     if (a.getArguments() != null) {
                         a = a.withArguments(ListUtils.map(a.getArguments(), arg -> requestMethodArg.get().equals(arg) ? null : arg));
                     }
                 }
 
                 // Change the Annotation Type
-                if (resolvedRequestMappingAnnotationClassName != null) {
-                    maybeAddImport("org.springframework.web.bind.annotation." + resolvedRequestMappingAnnotationClassName);
-                    a = (J.Annotation) new ChangeType("org.springframework.web.bind.annotation.RequestMapping",
-                            "org.springframework.web.bind.annotation." + resolvedRequestMappingAnnotationClassName, false)
-                            .getVisitor().visit(a, ctx, getCursor());
-                }
+                maybeAddImport("org.springframework.web.bind.annotation." + resolvedRequestMappingAnnotationClassName);
+                a = (J.Annotation) new ChangeType("org.springframework.web.bind.annotation.RequestMapping",
+                        "org.springframework.web.bind.annotation." + resolvedRequestMappingAnnotationClassName, false)
+                        .getVisitor().visit(a, ctx, getCursor());
 
                 // if there is only one remaining argument now, and it is "path" or "value", then we can drop the key name
                 if (a != null && a.getArguments() != null && a.getArguments().size() == 1) {
@@ -142,15 +140,23 @@ private boolean methodArgumentHasSingleType(J.Assignment assignment) {
             return newArray.getInitializer() != null && newArray.getInitializer().size() == 1;
         }
 
+        @Nullable
         private String requestMethodType(@Nullable J.Assignment assignment) {
+            if(assignment == null) {
+                return null;
+            }
             if (assignment.getAssignment() instanceof J.Identifier) {
                 return ((J.Identifier) assignment.getAssignment()).getSimpleName();
             } else if (assignment.getAssignment() instanceof J.FieldAccess) {
                 return ((J.FieldAccess) assignment.getAssignment()).getSimpleName();
             } else if (methodArgumentHasSingleType(assignment)) {
-                J.NewArray newArray = (J.NewArray) assignment.getAssignment();
-                assert newArray.getInitializer() != null;
-                return ((J.FieldAccess) newArray.getInitializer().get(0)).getSimpleName();
+                if(assignment.getAssignment() instanceof J.NewArray) {
+                    J.NewArray newArray = (J.NewArray) assignment.getAssignment();
+                    assert newArray.getInitializer() != null;
+                    return ((J.FieldAccess) newArray.getInitializer().get(0)).getSimpleName();
+                } else if(assignment.getAssignment() instanceof J.Identifier) {
+                    return ((J.Identifier) assignment.getAssignment()).getSimpleName();
+                }
             }
             return null;
         }