//Copyright 2003-2005 Arthur van Hoff, Rick Blair
//Licensed under Apache License version 2.0
//Original license LGPL
package javax.jmdns.impl.tasks;
import java.util.Timer;
import java.util.TimerTask;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.jmdns.impl.DNSConstants;
import javax.jmdns.impl.DNSOutgoing;
import javax.jmdns.impl.DNSQuestion;
import javax.jmdns.impl.DNSRecord;
import javax.jmdns.impl.DNSState;
import javax.jmdns.impl.JmDNSImpl;
import javax.jmdns.impl.ServiceInfoImpl;
/**
* The ServiceInfoResolver queries up to three times consecutively for
* a service info, and then removes itself from the timer.
* <p/>
* The ServiceInfoResolver will run only if JmDNS is in state ANNOUNCED.
* REMIND: Prevent having multiple service resolvers for the same info in the
* timer queue.
*/
public class ServiceInfoResolver extends TimerTask
{
static Logger logger = Logger.getLogger(ServiceInfoResolver.class.getName());
/**
*
*/
private final JmDNSImpl jmDNSImpl;
/**
* Counts the number of queries being sent.
*/
int count = 0;
private ServiceInfoImpl info;
public ServiceInfoResolver(JmDNSImpl jmDNSImpl, ServiceInfoImpl info)
{
this.jmDNSImpl = jmDNSImpl;
this.info = info;
info.setDns(this.jmDNSImpl);
this.jmDNSImpl.addListener(info, new DNSQuestion(info.getQualifiedName(), DNSConstants.TYPE_ANY, DNSConstants.CLASS_IN));
}
public void start(Timer timer)
{
timer.schedule(this, DNSConstants.QUERY_WAIT_INTERVAL, DNSConstants.QUERY_WAIT_INTERVAL);
}
public void run()
{
try
{
if (this.jmDNSImpl.getState() == DNSState.ANNOUNCED)
{
if (count++ < 3 && !info.hasData())
{
long now = System.currentTimeMillis();
DNSOutgoing out = new DNSOutgoing(DNSConstants.FLAGS_QR_QUERY);
out.addQuestion(new DNSQuestion(info.getQualifiedName(), DNSConstants.TYPE_SRV, DNSConstants.CLASS_IN));
out.addQuestion(new DNSQuestion(info.getQualifiedName(), DNSConstants.TYPE_TXT, DNSConstants.CLASS_IN));
if (info.getServer() != null)
{
out.addQuestion(new DNSQuestion(info.getServer(), DNSConstants.TYPE_A, DNSConstants.CLASS_IN));
}
out.addAnswer((DNSRecord) this.jmDNSImpl.getCache().get(info.getQualifiedName(), DNSConstants.TYPE_SRV, DNSConstants.CLASS_IN), now);
out.addAnswer((DNSRecord) this.jmDNSImpl.getCache().get(info.getQualifiedName(), DNSConstants.TYPE_TXT, DNSConstants.CLASS_IN), now);
if (info.getServer() != null)
{
out.addAnswer((DNSRecord) this.jmDNSImpl.getCache().get(info.getServer(), DNSConstants.TYPE_A, DNSConstants.CLASS_IN), now);
}
this.jmDNSImpl.send(out);
}
else
{
// After three queries, we can quit.
this.cancel();
this.jmDNSImpl.removeListener(info);
}
}
else
{
if (this.jmDNSImpl.getState() == DNSState.CANCELED)
{
this.cancel();
this.jmDNSImpl.removeListener(info);
}
}
}
catch (Throwable e)
{
logger.log(Level.WARNING, "run() exception ", e);
this.jmDNSImpl.recover();
}
}
}