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package JACE.netsvcs.Time;
import java.io.*;
import java.net.*;
import JACE.OS.*;
import JACE.Connection.*;
import JACE.ASX.*;
/**
* Requests a time update from a time server. This is used by the
* TSClerkProcessor to query a server.
*/
public class TSClerkHandler extends SvcHandler
{
/**
* Constructor.
*
*@param parent TSClerkProcessor which is creating this instance
*@param host name of the machine this handler is connected to
*@param port port on the time server to connect to
*/
public TSClerkHandler (TSClerkProcessor parent,
String host,
int port)
{
parent_ = parent;
host_ = host;
port_ = port;
}
/**
* Initialize this handler. Called automatically by Connector when a
* successful connection is made.
*
*@return -1 on failure, 0 on success
*/
public int open (Object obj)
{
ACE.DEBUG ("Successful connection to " + host ());
connected (true);
return 0;
}
/**
* Safely shut down this handler, closing the socket.
*
*@return -1 on failure, 0 on success
*/
public synchronized int close ()
{
if (!connected ())
return 0;
ACE.DEBUG ("Shutting down connection to " + host ());
try {
peer ().close ();
} catch (IOException e) {
return -1;
} finally {
connected (false);
}
return 0;
}
/**
* Accessor for the port number of the server.
*/
public int port ()
{
return port_;
}
/**
* Accessor for the host name of the server.
*/
public String host ()
{
return host_;
}
/**
* Check to see if this handler is currently connected to a server.
*/
public synchronized boolean connected ()
{
return connected_;
}
/**
* Set the connected state.
*
*@param state true if connected, false if not
*/
protected synchronized void connected (boolean state)
{
connected_ = state;
}
/**
* (Isn't used, just fulfills the interface. Returns -1 by
* default)
*/
public int handleTimeout (TimeValue tv, Object obj)
{
return -1;
}
/**
* (Isn't used, just fulfills the interface.)
*/
public void run ()
{
ACE.ERROR ("TSClerkHandler is not setup to run in its own thread");
}
/**
* Sends a request to the server and waits for a reply. This is called
* by TSClerkProcessor.
*
*@return -1 on failure, 0 on success
*/
public int sendRequest ()
{
// Ask the clerk processor to connect this handler if it isn't
// already. Thus, it tries to reconnect if the server has gone
// down.
if (!connected ())
parent_.connectHandler (this, host_, port_);
TimeRequest request = new TimeRequest ();
long start, stop;
try {
start = System.currentTimeMillis ();
request.streamOutTo (peer().outputStream ());
request.streamInFrom (peer().inputStream ());
stop = System.currentTimeMillis ();
} catch (NullPointerException e) {
close ();
return -1;
} catch (IOException e) {
close ();
return -1;
}
// Compute the difference in the local time and the server time
// (in seconds)
long difference = request.time () - (stop / 1000);
// Calculate the transmission time (in seconds)
long oneWayTime = (stop - start) / 2000;
difference += oneWayTime;
/*
ACE.DEBUG (host() + " reports:");
ACE.DEBUG (" time difference: " + difference);
ACE.DEBUG (" trans. delay: " + oneWayTime);
*/
// Set the time difference for this handler
delta (difference);
return 0;
}
/**
* Returns the current time difference between local time and
* the server (in seconds).
*/
public synchronized long delta ()
{
return delta_;
}
/**
* Sets the current time difference between local time and the
* server (in seconds).
*/
protected synchronized void delta (long delta)
{
delta_ = delta;
}
private long delta_;
private TSClerkProcessor parent_;
private boolean connected_ = false;
private String host_;
private int port_;
}
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