Java, Hyperterminal, File Transfer


J

JP

Hi,

I *really* need some help with a particular task I'm trying to
accomplish...

In essense, I want to dial up a number, bring up a terminal window,
type in username, password, and then send a text file. There is a form
that I need to fill out with info, and then I need to select a file
and send it.

I can do all this in Hyperterminal, but that's not what I want to do.
I need to do this in Java, hopefully... and I've read the javax.comm
things over and over, but I didn't really see how I'd populate a form
or send a file using javax.comm package... if anyone has any sample
code that'd be really great!

Thank you very much!

James
 
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R

Rhino

JP said:
Hi,

I *really* need some help with a particular task I'm trying to
accomplish...

In essense, I want to dial up a number, bring up a terminal window,
type in username, password, and then send a text file. There is a form
that I need to fill out with info, and then I need to select a file
and send it.

I can do all this in Hyperterminal, but that's not what I want to do.
I need to do this in Java, hopefully... and I've read the javax.comm
things over and over, but I didn't really see how I'd populate a form
or send a file using javax.comm package... if anyone has any sample
code that'd be really great!
Displaying a form or a series of forms which prompt users for information is
not terribly hard. Doing a file transfer is not difficult either. I've done
both in the same servlet.

A couple of years ago, I created a simple prototype which asks users for
information, then creates a zip file containing several files, one of which
is a spontaneously-generated file containing a random "key". The servlet
then takes the user to a download page where they can download this file. I
didn't use javax.comm at all as far as I can recall. Would the code for that
prototype help you? Or would a servlet solution not appeal to you?

For what it's worth, I've never tried to dial a phone number or bring up a
terminal window in my own code; I tend to use existing tools like telnet or
sshwin for that ;-) However, if my prototype would help you, I'd be happy to
send you the code, although it won't be as useful if you don't have a
servlet container like Tomcat set up since you won't be able to execute the
code or step through it with a debugger to see how it works.

Is this a school assignment or are you doing real work, either for yourself
or an employer?

Rhino
 
P

Paul Lutus

JP said:
Hi,

I *really* need some help with a particular task I'm trying to
accomplish...

In essense, I want to dial up a number, bring up a terminal window,
type in username, password, and then send a text file. There is a form
that I need to fill out with info, and then I need to select a file
and send it.

I can do all this in Hyperterminal, but that's not what I want to do.
I need to do this in Java, hopefully... and I've read the javax.comm
things over and over, but I didn't really see how I'd populate a form
or send a file using javax.comm package... if anyone has any sample
code that'd be really great!

This is not an automatic code creation machine. Please post your code and
ask specific questions.
 
G

G Winstanley

This is not an automatic code creation machine. Please post your code and
ask specific questions.

But it seems that you might be an automaton Paul. Almost every post I see
here from you is simply complaining that people don't post code. OP is
asking for generic advice on solving a problem, which is a very valid reason
for using this NG. He obviously requires direction rather than criticism.

But I digress. My experience with javax.comm has been fairly unconstructive,
but I had headaches with serial port timings for a specific device. My
advice, James, would be to search Google (and other sources) as much as
possible for related projects which use the JavaCOMM package. It doesn't
seem to be as widely-used as I originally thought it might, which leads me
to believe that many people have tried and then gone to other solutions.

As for dialing, I've heard many people asking about it, but very few with
answers. It's possible you will have some luck by looking at the JTAPI area
of Sun's Java site.

Stan
 
P

Paul Lutus

G said:
But it seems that you might be an automaton Paul. Almost every post I see
here from you is simply complaining that people don't post code.

And that problem is solved by having people post their code along with their
code creation questions. The reply I gave, by the way, is hardly limited to
me. All the regulars offer the same advice.
OP is
asking for generic advice on solving a problem, which is a very valid
reason for using this NG. He obviously requires direction rather than
criticism.

Which criticism was that? Point it out.
But I digress.

/ ...
It's possible you will have some luck by looking at the JTAPI
area of Sun's Java site.

And it would be tremendously beneficial if the OP were to post the code that
causes the problem, along with any error message he sees. How does he know
he has a problem? His code doesn't work. Where is the code?
 
J

JP

Paul Lutus said:
This is not an automatic code creation machine. Please post your code and
ask specific questions.

Sure, I understand.

Here's a routine. The premise is that a connection to a remote
computer has been established via modem and a phone line, and the
remote computer has a form where a user needs to populate the
destination username, and a subject, and then attach a file for
sending. We are NOT connecting via the INTERNET. There is NO URL or
anything like that. The connection is made by using the modem to DIAL
A PHONE NUMBER into a remote computer... and then communicate with the
remote computer and hopefully send a text file from the local box
through the modem, using zmodem protocol...

THIS BELOW DOES NOT WORK because I don't know how to send a file.

....
outputStream = serialPort.getOutputStream();
inputStream = serialPort.getInputStream();
....
public void sendFile(){
try {
outputStream.write(username.getBytes()); //To:
wait(2000);
outputStream.write(TAB_KEY); //tab
outputStream.write(65); //Subject: // A
wait(2000);
outputStream.write(TAB_KEY); //tab
outputStream.write(TAB_KEY); //tab
String filename = "C:\temp\test.txt"; // file name has
been altered.
outputStream.write(filename.getBytes()); //file name //A

outputStream.write(ENTER_KEY); //
while (true){
inputStream.read();
wait(50000);
}
} catch (IOException e) {
System.out.println(e);
e.printStackTrace();
}
}

1) Are we correct to assume that by writing into the outputStream of
the serialport object (through a combination of alphanumerics and
tabs/enters, etc) we are in fact populating the form?
2) How do we send a file? After we populate the form with a username,
a subject line, and a file name, we then need to submit a file. In
HyperTerminal, we do this by "Send/Receive File" functions... we need
to write this obviously... do we just write ATSZ into the modem? What
about the form that we read from the inputStream?

Thanks in advance,

James
 
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P

Paul Lutus

JP wrote:

/ ...
THIS BELOW DOES NOT WORK because I don't know how to send a file.

The problem you face is that you have a single bidirectional serial stream
for all communications with the client. You need to send command/display
data as well as file data along this path.

There are several apporoaches to solving this problem. Some are already
written, but you can write your own. The latter might be a better approach.

Suggestion. For all command/display information, send lines containing a
label and text (name/value pairs). If the name specifies a form element,
the value goes there. If the name specifies a command setting, the value is
applied accordingly.

For a file transfer, use a name of:

file:(path/name):length (linefeed)

On receipt of this command, the client will switch to a file download mode
for the number of bytes specified in "length". When the file download is
finished, the client will reply:

checksum:(checksum) (linefeed)

This will indicate that the file was received and the server can check the
value of the checksum against the original file.

Plenty has been left out of this brief summary, like dealing with dropped
bytes and coping with errors. But it is best to use an 8-bit serial
configuration, to simplify the file transfer requirement. Even this can be
gotten around, but things get much more complex using less than 8-bit
serial data.
 
G

G Winstanley

And that problem is solved by having people post their code along with their
code creation questions. The reply I gave, by the way, is hardly limited to
me. All the regulars offer the same advice.


Which criticism was that? Point it out.

It was an indirect criticism of not posting any code, thereby not enabling
anyone to help. It's simply not the case that a problem *requires* code
submission to be answered usefully.
/ ...


And it would be tremendously beneficial if the OP were to post the code that
causes the problem, along with any error message he sees. How does he know
he has a problem? His code doesn't work. Where is the code?

I agree with this sentiment, but it's quite possible he has no code yet and
is probing the community to find out if he can shortcut the process before
writing code which has already been written by another. If code has already
been written then I totally agree that posting it helps a great deal.
Looking at the OP's post I find nothing that explicitly references that h
has already written any code, so asking to see it so bluntly seems
pointless.

My minor gripe is that often I see complaints of no code, or perhaps
requests for code, when in many cases it is simply not appropriate. For many
who have a fair amount of coding experience this is fine as they will
already have tried something which aims to fit the bill, but many are simply
seeking advice before a potential coding disaster and they are in the NG to
learn. (I know, try coding first and see where it gets you, but not everyone
subscribed to that policy.) Anyhow, this is not the place to quibble such
minor issues. We're all here to gain knowledge and help others. To put it
simply...not every problem requires posted code.

Stan

P.S. JTides looks interesting. I'll take a closer look when I get a chance.
Could come in useful for scuba diving trips.
 
J

JP

Hello again,

I just read through some more info and found out that apparently there
are zmodem implementations in Java available, except I have to
purchase them... I am not sure if purchasing is an option at this
point, does anyone know of a free implementation of zmodem file
transfer protocol that's in Java?

If not, how about just some general ideas as to how I can implement
zmodem protocol? Or is this a non-trivial task?

Thank you,

James
 
P

Paul Lutus

G said:
It was an indirect criticism of not posting any code, thereby not enabling
anyone to help.

That is not a criticism, unless all teaching is criticism in disguise.
It's simply not the case that a problem *requires* code
submission to be answered usefully.

It is the case in this case.
 
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