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Hello,

We need to write text-based (no GUI) Java applications that output to
ANSI terminals across a network, using telnet. Anybody know of a
library similar to AWT or SWING that offers window management, edit
controls and the like, for text-based applications?

Many thanks,

Michel Pelletier

Michel Pelletier <> writes:
> We need to write text-based (no GUI) Java applications that output to
> ANSI terminals across a network, using telnet. Anybody know of a
> library similar to AWT or SWING that offers window management, edit
> controls and the like, for text-based applications?

There is no pure Java library at all for terminal I/O (one can't do the
necessary line control for terminals via the Reader/Writer/Stream
APIs).

There are some low-level libraries which e.g. wrap the Unix curses
API. Google for jcurses (several libs use this name) or javacurses.
One of these j*curses library (sorry, forgot whiche name), is suppossed
to also offer some higher-level "widgets". And there is charva, which
claims to be a drop-in replacement for AWT.

/Thomas

Thomas Weidenfeller wrote:

> There is no pure Java library at all for terminal I/O (one can't do the
> necessary line control for terminals via the Reader/Writer/Stream
> APIs).

If you're writing to an ANSI (or VT52/VT100/VT220/whatever) terminal
you should be able to do this by writing the correct line-control codes
to System.out. You'd have to put together the line control codes
yourself, and embed them into your output.

Mind you, I don't know of any library that currently implements this.

Brad BARCLAY

--
=-=-=-=-=-=-=-=-=
From the OS/2 WARP v4.5 Desktop of Brad BARCLAY.
The jSyncManager Project: http://www.jsyncmanager.org


Michel Pelletier wrote:

> Hello,
>
> We need to write text-based (no GUI) Java applications that output to
> ANSI terminals across a network, using telnet. Anybody know of a
> library similar to AWT or SWING that offers window management, edit
> controls and the like, for text-based applications?
>
> Many thanks,
>
> Michel Pelletier
>

Try TUI:

http://www.bmsi.com/tuipeer/

Jeff

--
Jeffrey Palm --> http://www.ccs.neu.edu/home/jpalm

Brad BARCLAY <> writes:
> If you're writing to an ANSI (or VT52/VT100/VT220/whatever) terminal
> you should be able to do this by writing the correct line-control codes
> to System.out. You'd have to put together the line control codes
> yourself, and embed them into your output.

It is not the terminal control which is the problem here. It is
controlling the communication line (if you still have a physical line
running to that one terminal), e.g. setting it to 9600 baud, 7bit, odd
parity, two stop bits, and controlling your OS', e.g. setting a
terminal driver to not map NL to CR (or to map it), or getting fill
characters over the line if you have delays. Or, to make sure
System.in/out don't buffer.

> Mind you, I don't know of any library that currently implements this.

A long time ago I started writing a pure Java library for terminal I/O
(using the old termcap format for terminal capability descriptions),
but gave up due to the lack of control one has over System.out, or any
other Reader/Writer/Stream. There was, e.g. no way to guarantee the
delays some real terminals need after they e.g. get a backspace or CR.
There was no way to ensure System.in/out are unbuffered, etc.

I am convinced that one needs JNI, or a library using JNI, to do any
kind of useful non trivial terminal I/O in Java.

/Thomas

"Thomas Weidenfeller" <> wrote in message
news:bqnjje$m22$...
> Brad BARCLAY <> writes:
> > If you're writing to an ANSI (or VT52/VT100/VT220/whatever) terminal
> > you should be able to do this by writing the correct line-control codes
> > to System.out. You'd have to put together the line control codes
> > yourself, and embed them into your output.
>
> It is not the terminal control which is the problem here. It is
> controlling the communication line (if you still have a physical line
> running to that one terminal), e.g. setting it to 9600 baud, 7bit, odd
> parity, two stop bits, and controlling your OS', e.g. setting a
> terminal driver to not map NL to CR (or to map it), or getting fill
> characters over the line if you have delays. Or, to make sure
> System.in/out don't buffer.
>
> > Mind you, I don't know of any library that currently implements this.
>
> A long time ago I started writing a pure Java library for terminal I/O
> (using the old termcap format for terminal capability descriptions),
> but gave up due to the lack of control one has over System.out, or any
> other Reader/Writer/Stream. There was, e.g. no way to guarantee the
> delays some real terminals need after they e.g. get a backspace or CR.
> There was no way to ensure System.in/out are unbuffered, etc.
>
> I am convinced that one needs JNI, or a library using JNI, to do any
> kind of useful non trivial terminal I/O in Java.

The original poster asked about telnet. No serial port involved.

I am interested to know if you used the optional javax.comm pack
http://java.sun.com/products/javacomm/ for your experiments?
I would be surprised if the wanted functionality you describe
above is not possible with it. But since I have never tested it,
it could be correct that it is not of course.

Roald

"Roald Ribe" <> writes:
> The original poster asked about telnet. No serial port involved.

Yes, but similar problems. E.g. one needs to make sure telnet is
running in character-by-character mode, and that the bunch of control
characters telnet usually interprets are passed through transparently.
I didn't see a way to control this if all one has is a
Reader/Writer/Stream.

> I am interested to know if you used the optional javax.comm pack
> http://java.sun.com/products/javacomm/ for your experiments?

I know about it, but it wasn't going to fix my primary problem. What is
a terminal library good for that can write to the serial lines only,
but not to the system console?


/Thomas