/**
* Constructor, specifying the server host:port combination, login data and an output stream.
*
* @param host server name
* @param port server port
* @param user user name
* @param pass password
* @param output client output; if set to {@code null}, results will be returned as strings.
* @throws IOException I/O exception
*/
public ClientSession(
final String host,
final int port,
final String user,
final String pass,
final OutputStream output)
throws IOException {
super(output);
ehost = host;
socket = new Socket();
try {
// limit timeout to five seconds
socket.connect(new InetSocketAddress(host, port), 5000);
} catch (final IllegalArgumentException ex) {
throw new BaseXException(ex);
}
sin = socket.getInputStream();
// receive timestamp
final BufferInput bi = new BufferInput(sin);
final String ts = bi.readString();
// send user name and hashed password/timestamp
sout = PrintOutput.get(socket.getOutputStream());
send(user);
send(Token.md5(Token.md5(pass) + ts));
sout.flush();
// receive success flag
if (!ok(bi)) throw new LoginException();
}
/**
* Executes a command and sends the result to the specified output stream.
*
* @param cmd server command
* @param arg argument
* @param os target output stream
* @return string
* @throws IOException I/O exception
*/
protected String exec(final ServerCmd cmd, final String arg, final OutputStream os)
throws IOException {
final OutputStream o = os == null ? new ArrayOutput() : os;
sout.write(cmd.code);
send(arg);
sout.flush();
final BufferInput bi = new BufferInput(sin);
ClientSession.receive(bi, o);
if (!ClientSession.ok(bi)) throw new BaseXException(bi.readString());
return o.toString();
}
/**
* Watches an event.
*
* @param name event name
* @param notifier event notification
* @throws IOException I/O exception
*/
public void watch(final String name, final EventNotifier notifier) throws IOException {
sout.write(ServerCmd.WATCH.code);
if (esocket == null) {
sout.flush();
final BufferInput bi = new BufferInput(sin);
final int eport = Integer.parseInt(bi.readString());
// initialize event socket
esocket = new Socket();
esocket.connect(new InetSocketAddress(ehost, eport), 5000);
final OutputStream so = esocket.getOutputStream();
so.write(bi.readBytes());
so.write(0);
so.flush();
final InputStream is = esocket.getInputStream();
is.read();
listen(is);
}
send(name);
sout.flush();
receive(null);
notifiers.put(name, notifier);
}
/**
* Checks the next success flag.
*
* @param bi buffer input
* @return value of check
* @throws IOException I/O exception
*/
protected static boolean ok(final BufferInput bi) throws IOException {
return bi.read() == 0;
}
/**
* Receives the info string.
*
* @param os output stream to send result to. If {@code null}, no result will be requested
* @throws IOException I/O exception
*/
private void receive(final OutputStream os) throws IOException {
final BufferInput bi = new BufferInput(sin);
if (os != null) receive(bi, os);
info = bi.readString();
if (!ok(bi)) throw new BaseXException(info);
}