@Override
    protected Object convertFromInternal(Message<?> message, Class<?> targetClass, Object conversionHint) {
        // parse byte[] or String payload to Java Object
        Object payload = message.getPayload();
        Object obj = null;
        if (payload instanceof byte[]) {
            obj = JSON.parseObject((byte[]) payload, targetClass, fastJsonConfig.getFeatures());
        } else if (payload instanceof String) {
            obj = JSON.parseObject((String) payload, targetClass, fastJsonConfig.getFeatures());
        }

        return obj;
    }
@param fastJsonConfig the fastJsonConfig to set.
fastjson1-compatible/src/main/java/com/alibaba/fastjson/support/spring/messaging/MappingFastJsonMessageConverter.java