Sockets for Clients - Java Network Programming - page 247

Escape character is '^]'.
220 pan.alephnull.com dictd 1.12.0/rf on Linux 3.0.0-14-server
<auth.mime> <[e-mail]>
DEFINE eng-lat gold
150 1 definitions retrieved
151 "gold" eng-lat "English-Latin Freedict dictionary"
gold [gould]
aurarius; aureus; chryseus
aurum; chrysos
.
250 ok [d/m/c = 1/0/10; 0.000r 0.000u 0.000s]
DEFINE eng-lat computer
552 no match [d/m/c = 0/0/9; 0.000r 0.000u 0.000s]
quit
221 bye [d/m/c = 0/0/0; 42.000r 0.000u 0.000s]
You can see that control response lines begin with a three-digit code. The actual defi‐
nition is plain text, terminated with a period on a line by itself. If the dictionary doesn't
contain the word you asked for, it returns 552 no match. Of course, you could also find
this out, and a lot more, by reading the RFC.
It's not hard to implement this protocol in Java. First, open a socket to a dict server—
_dict.org__ is a good one—on port 2628:
Socket socket = new Socket ( "dict.org" , 2628 );
Once again you'll want to set a timeout in case the server hangs while you're connected
to it:
socket . setSoTimeout ( 15000 );
In the dict protocol, the client speaks first, so ask for the output stream using getOut
putStream() :
OutputStream out = socket . getOutputStream ();
The getOutputStream() method returns a raw OutputStream for writing data from
your application to the other end of the socket. You usually chain this stream to a more
convenient class like DataOutputStream or OutputStreamWriter before using it. For
performance reasons, it's a good idea to buffer it as well. Because the dict protocol is
text based, more specifically UTF-8 based, it's convenient to wrap this in a Writer :
Writer writer = new OutputStreamWriter ( out , "UTF-8" );
Now write the command over the socket:
writer . write ( "DEFINE eng-lat gold\r\n" );
Finally, flush the output so you'll be sure the command is sent over the network:
writer . flush ();