public static Type getCollectionItemType(Type fieldType) {
        if (fieldType instanceof ParameterizedType) {
            return getCollectionItemType((ParameterizedType) fieldType);
        }
        if (fieldType instanceof Class<?>) {
            return getCollectionItemType((Class<?>) fieldType);
        }
        return Object.class;
    }
resolve property name from get/set method name

@param methodName get/set method name
@return property name
src/main/java/com/alibaba/fastjson/util/TypeUtils.java