/**
* 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);
}
/**
* Retrieves data from the server.
*
* @param bi buffered server input
* @param os output stream
* @throws IOException I/O exception
*/
protected static void receive(final BufferInput bi, final OutputStream os) throws IOException {
final DecodingInput di = new DecodingInput(bi);
for (int b; (b = di.read()) != -1; ) os.write(b);
}