@Override
    protected Object convertFromInternal(Message<?> message, Class<?> targetClass, Object conversionHint) {
        // parse byte[] or String payload to Java Object
        Object obj = null;
        Type type = getResolvedType(targetClass, conversionHint);
        Object payload = message.getPayload();

        if (payload instanceof byte[] && config.isJSONB()) {
            obj = JSONB.parseObject((byte[]) payload, type, config.getSymbolTable(), config.getReaderFilters(), config.getReaderFeatures());
        } else if (payload instanceof byte[] && !config.isJSONB()) {
            obj = JSON.parseObject((byte[]) payload, type, config.getDateFormat(), config.getReaderFilters(), config.getReaderFeatures());
        } else if (payload instanceof String && JSON.isValid((String) payload)) {
            obj = JSON.parseObject((String) payload, type, config.getDateFormat(), config.getReaderFilters(), config.getReaderFeatures());
        }
        return obj;
    }
@param fastJsonConfig the fastJsonConfig to set.
extension-spring5/src/main/java/com/alibaba/fastjson2/support/spring/messaging/converter/MappingFastJsonMessageConverter.java