Fix scanSuperTypes function to return Object Class instead of generic types

Author: yuanjin5

src/main/java/org/apache/ibatis/reflection/TypeParameterResolver.java

@@ -206,6 +206,9 @@ private static Type scanSuperTypes(TypeVariable<?> typeVar, Type srcType, Class<
       if (declaringClass == parentAsClass) {
         for (int i = 0; i < parentTypeVars.length; i++) {
           if (typeVar.equals(parentTypeVars[i])) {
+            if (parentAsType.getActualTypeArguments()[i] instanceof TypeVariable<?>) {
+              return Object.class;
+            }
             return parentAsType.getActualTypeArguments()[i];
           }
         }

src/test/java/org/apache/ibatis/reflection/TypeParameterResolverTest.java

@@ -261,6 +261,19 @@ void testReturn_Lv2WildcardList() throws Exception {
     assertEquals(String.class, wildcard.getUpperBounds()[0]);
   }
 
+  @Test
+  void testReturn_LV1Map() throws Exception {
+    Class<?> clazz = Level1Mapper.class;
+    Method method = clazz.getMethod("selectMap");
+    Type result = TypeParameterResolver.resolveReturnType(method, clazz);
+    assertTrue(result instanceof ParameterizedType);
+    ParameterizedType paramType = (ParameterizedType) result;
+    assertEquals(Map.class, paramType.getRawType());
+    assertEquals(2, paramType.getActualTypeArguments().length);
+    assertEquals(String.class, paramType.getActualTypeArguments()[0]);
+    assertEquals(Object.class, paramType.getActualTypeArguments()[1]);
+  }
+
   @Test
   void testReturn_LV2Map() throws Exception {
     Class<?> clazz = Level2Mapper.class;