in src/main/java/org/apache/log4j/receivers/net/UDPAppender.java [113:152]
public void activateOptions() {
try {
hostname = InetAddress.getLocalHost().getHostName();
} catch (UnknownHostException uhe) {
try {
hostname = InetAddress.getLocalHost().getHostAddress();
} catch (UnknownHostException uhe2) {
hostname = "unknown";
}
}
//allow system property of application to be primary
if (application == null) {
application = System.getProperty(Constants.APPLICATION_KEY);
} else {
if (System.getProperty(Constants.APPLICATION_KEY) != null) {
application = application + "-" + System.getProperty(Constants.APPLICATION_KEY);
}
}
if(remoteHost != null) {
address = getAddressByName(remoteHost);
connect(address, port);
} else {
String err = "The RemoteHost property is required for SocketAppender named "+ name;
LogLog.error(err);
throw new IllegalStateException(err);
}
if (layout == null) {
layout = new XMLLayout();
}
if (advertiseViaMulticastDNS) {
zeroConf = new ZeroConfSupport(ZONE, port, getName());
zeroConf.advertise();
}
super.activateOptions();
}