Try to fix

Author: zhangrongfan

mybatis-boost-core/src/main/java/cn/mybatisboost/json/JsonResultSetsHandler.java

@@ -34,7 +34,10 @@ public Object intercept(Invocation invocation) throws Throwable {
 
         for (Object object : proceed) {
             for (Field field : fields) {
-                Object value = ((Property<?>) field.get(object)).orElse(null);
+                Object value = field.get(object);
+                if (value != null) {
+                    value = ((Property<?>) value).get();
+                }
                 if (value instanceof String) {
                     field.set(object, Property.of(JsonTypeHandler.objectMapper.readValue((String) value,
                             (Class<?>) ((ParameterizedType) field.getGenericType()).getActualTypeArguments()[0])));