B4J Question Asyncstream - Send string and bytes combined

[Toley]

Hi,
In a part of the small app I'm working on, I have to send via asyncstream a string followed by 4 bytes. In fact the bytes I have to send are DateTime.Now which is a long type (8 bytes).

So I have 2 questions. How can I cast DateTime.Now into 4 bytes? And how can I append those bytes to a string and send the whole package via asyncstream?

Edit: Sorry I forgot to mention that I'm using AsyncStreamText.

Thanks everyone.

 

[Erel]

Are you sending the data between two Android devices?

 

[Toley]

No this is a B4J app that send data to an electronic device via jSerial. Since it's an AT commands communication, I have to use asyncstreamtext to make sure the packet is complete when the event is riased in the b4j app.

 

[Erel]

You can convert the long to 4 bytes with ByteConverter.LongsToBytes (Array As Long(DateTime.Now)).
Send the string and then send the bytes array. Or combine both of them to a larger array of bytes (ByteConverter.ArrayCopy will help).

 

[Toley]

Thank you Erel,
I've made some tries but I'm still unable to do what I need. To be clearer, my system needs the time in second since 1 jan 1970 in an 4 bytes format. So I have to divide DateTime.Now by 1000. This is not a problem.

But when I convert it to a byte array with ByteConverter.LongsToBytes like you suggest, I receive 8 bytes (see the attach screenshot). I'm only interested by the last 4 ones. I've try to send them with this line but I did not receive anything. AsyncstreamText expect a string as input.

astr.Write(BytesToString(buffer,4,4,"UTF-8"))

 

[Erel]

1. Use IntsToBytes instead of LongsToBytes.
2. Make astreams in AsyncStreamsText class public and write the bytes directly:

astr.astreams.Write(...)