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GCM sendRegistrationIdToBackend is undefined

I am trying to set up GCM but my project doesn't recognize certain methods. I followed the advice of many other links which was to import GCM and google play services but I am still getting no such luck. Thanks for looking.
Edit: I've cleaned a million times and rebuilt.

I'm not sure where you got the code of the demo app from, but there are several things wrong with it.
First of all, the method you are missing is not implemented in the Demo. It has an empty body :
/**
* Sends the registration ID to your server over HTTP, so it can use GCM/HTTP or CCS to send
* messages to your app. Not needed for this demo since the device sends upstream messages
* to a server that echoes back the message using the 'from' address in the message.
*/
private void sendRegistrationIdToBackend() {
// Your implementation here.
}
It's your responsibility to implement it, since its implementation depends on your server implementation.
Another error (you'd get an exception after you fix the compilation error) is calling gcm.register() from the main thread. You must call it in the background :
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mDisplay = (TextView) findViewById(R.id.display);
context = getApplicationContext();
// Check device for Play Services APK. If check succeeds, proceed with GCM registration.
if (checkPlayServices()) {
gcm = GoogleCloudMessaging.getInstance(this);
regid = getRegistrationId(context);
if (regid.isEmpty()) {
registerInBackground();
}
} else {
Log.i(TAG, "No valid Google Play Services APK found.");
}
}
/**
* Registers the application with GCM servers asynchronously.
* <p>
* Stores the registration ID and the app versionCode in the application's
* shared preferences.
*/
private void registerInBackground() {
new AsyncTask<Void, Void, String>() {
#Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regid = gcm.register(SENDER_ID);
msg = "Device registered, registration ID=" + regid;
// You should send the registration ID to your server over HTTP, so it
// can use GCM/HTTP or CCS to send messages to your app.
sendRegistrationIdToBackend();
// For this demo: we don't need to send it because the device will send
// upstream messages to a server that echo back the message using the
// 'from' address in the message.
// Persist the regID - no need to register again.
storeRegistrationId(context, regid);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
// If there is an error, don't just keep trying to register.
// Require the user to click a button again, or perform
// exponential back-off.
}
return msg;
}
#Override
protected void onPostExecute(String msg) {
mDisplay.append(msg + "\n");
}
}.execute(null, null, null);
}
All code samples are taken from the official GCM Demo app.

gcm returns service not available

I have this code. I enter the project key from the Google console as the snederId and get an error:
service not available.
which steps would you recommend for me to double check in setting up the registration key?
private void registerInBackground() {
new AsyncTask<Void, Void, String>() {
#Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regId = gcm.register(SENDER_ID);
msg = "Device registered, registration ID=" + regId;
// You should send the registration ID to your server over
// HTTP, so it
// can use GCM/HTTP or CCS to send messages to your app.
sendRegistrationIdToBackend();
saveRegIdToDb();
// For this demo: we don't need to send it because the
// device will send
// upstream messages to a server that echo back the message
// using the
// 'from' address in the message.
// Persist the regID - no need to register again.
storeRegistrationId(context, regId);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
// If there is an error, don't just keep trying to register.
// Require the user to click a button again, or perform
// exponential back-off.
}
return msg;
}
#Override
protected void onPostExecute(String msg) {
// mDisplay.append(msg + "\n");
}
}.execute(null, null, null);
}

Some basic checks:
Was your project whitelisted by Google?
Do you use the correct sender_id (project number)?
Is network connection up?
Are Google Play Services installed and up to date?
One of the above checks should not be OK.

check sender id, it is project number
and turn on "APIs & auth" -> "Google Cloud Messaging for Android"

issue with reliable service discovery

I am banging my head on the wall. It works, but it doesn't work.
Let me clarify, testing is on a LG Optimus G, A Galaxy S4, and a Lenovo Tablet all running 4.1+
I am launching a server on each device, each device is broadcasting itself on a port, and when the user hits send, all devices that have had their service resolved, and their service has not been lost, a thread will loop launching other threads to connect to the servers broadcasting themselves, and send the data. The servers accept the incoming connection, hand it off to a thread, and then re-open themselves.
So recap, every device has is broadcasting a server, every device is supposed to know and keep track of other servers, when data is sent all known servers get hit.
My issue is that in 2/3 devices connections can consistently be established with the device's self.
Either phone, but only 1 of them at a time, seems to know about the other phone and is able to connect to the other phone. i.e. Galaxy S4 can say hi to Optimus G, but Optimus G cannot say hi except only to itself, or vice-verse.
So the discovering portion seems unreliable, and I do not know if it is me, Android, or the devices. I need outside eyes. I have tried to lay this out in a understandable and thought out manner, and I appreciate any help from any one who has knowledge on this issue as I am just making humble beginnings into the world of networks, and am more then willing to learn from someone.
I need a more reliable way of keeping track of services, or discovering them, as my implementation at least seems flawed.
I thank any help in advanced. (I do not believe this is a area that is trodden as heavily as most other android areas.)
Here is where the initialization is done.
/**initilize everything*/
private void buildNetwork()
{
Log.d(TAG, "buildNetwork");
networkHelper = new NetworkServiceDiscoveryHelper(this);
networkHelper.initializeNsd(this);
networkHelper.discoverServices();
connectionReceiver = new ConnectionReceiver(this, this);
// this next line launches the server thread which will obtain a socket
// to be used in the finishBuildingNetwork()
new Thread(connectionReceiver).start();
}
/** after the serversocket has been given a port we need to broadcast it*/
private void finishBuildingNetwork(int port)
{
Log.d(TAG, "finishBuildingNetwork");
networkHelper.registerService(port);
}
This is my somewhat changed implementation of a common NSDManager helper class.
public class NetworkServiceDiscoveryHelper
{
public static final String TAG = "NetworkServiceDiscoveryHelper";
public static final String KEY_DEVICE = "device";
Context mContext;
NsdManager mNsdManager;
NsdManager.ResolveListener mResolveListener;
NsdManager.DiscoveryListener mDiscoveryListener;
NsdManager.RegistrationListener mRegistrationListener;
public static final String SERVICE_TYPE = "_http._tcp.";
public String mServiceName = "BlurbChat";
NsdServiceInfo mService;
private DiscoveredDevicesManager deviceManager;
private NetworkDiscoveryHelperListener helperListener;
/**
*
* #param context
* - the activity context the service is to be attached to
*/
public NetworkServiceDiscoveryHelper(Context context)
{
mContext = context;
mNsdManager = (NsdManager) context.getSystemService(Context.NSD_SERVICE);
deviceManager = new DiscoveredDevicesManager();
}
/**
* initialize the NetworkServiceDiscovery
*/
public void initializeNsd(NetworkDiscoveryHelperListener helperListener)
{
this.helperListener = helperListener;
initializeResolveListener();
initializeDiscoveryListener();
initializeRegistrationListener();
// mNsdManager.init(mContext.getMainLooper(), this);
}
private void initializeDiscoveryListener()
{
mDiscoveryListener = new NsdManager.DiscoveryListener()
{
#Override
public void onDiscoveryStarted(String regType)
{
Log.d(TAG, "Service discovery started");
helperListener.SERVICE_STARTED(regType);
}
#Override
public void onServiceFound(NsdServiceInfo service)
{
// A service was found! Do something with it.
Log.d(TAG, "Service discovery success" + service);
if (!service.getServiceType().equals(SERVICE_TYPE))
{
// Service type is the string containing the protocol and
// transport layer for this service.
Log.d(TAG, "Unknown Service Type: " + service.getServiceType());
}
else if (service.getServiceName().contains(mServiceName))
{
// we have found our service! we use .contains because if
// there are multiple device with the same service being
// broadcast they will appear with name + (index)
// Resolve a discovered service. An application can resolve
// a service right before establishing a connection to fetch
// the IP and port details on which to setup the connection.
Log.d(TAG, "Found My Service Type: " + service.getServiceType() + service.getServiceName());
helperListener.SERVICE_FOUND(service);
mNsdManager.resolveService(service, mResolveListener);
}
/***************************************************************
* Checking the service name isn't always necessary, and is only relevant if you want to connect to a specific application.
* For instance, the application might only want to connect to instances of itself running on other devices. However, if the
* application wants to connect to a network printer, it's enough to see that the service type is "_ipp._tcp".
******************************************************/
}
/**
* when we lose our service
*/
#Override
public void onServiceLost(NsdServiceInfo service)
{
// When the network service is no longer available.
Log.e(TAG, "service lost" + service);
// remove the service
if (deviceManager.removeDevice(service) != null)
{
helperListener.SERVIVCE_LOST(service);
}
}
/**
* when our service is stopped
*/
#Override
public void onDiscoveryStopped(String serviceType)
{
Log.i(TAG, "Discovery stopped: " + serviceType);
helperListener.DISCOVERY_STOPPED(serviceType);
}
#Override
public void onStartDiscoveryFailed(String serviceType, int errorCode)
{
Log.e(TAG, "Discovery failed: Error code:" + errorCode);
helperListener.DISCOVERY_START_FAILED(serviceType, errorCode);
mNsdManager.stopServiceDiscovery(this);
}
#Override
public void onStopDiscoveryFailed(String serviceType, int errorCode)
{
helperListener.DISCOVERY_STOP_FAILED(serviceType, errorCode);
Log.e(TAG, "Discovery failed: Error code:" + errorCode);
mNsdManager.stopServiceDiscovery(this);
}
};
}
private void initializeResolveListener()
{
mResolveListener = new NsdManager.ResolveListener()
{
#Override
public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode)
{
// Called when the resolve fails. Use the error code to debug.
Log.e(TAG, "Resolve failed" + errorCode);
helperListener.RESOLVE_FAILED(serviceInfo, errorCode);
}
#Override
public void onServiceResolved(NsdServiceInfo serviceInfo)
{
Log.e(TAG, "Resolve Succeeded. " + serviceInfo);
if (serviceInfo.getServiceName().equals(mServiceName))
{
Log.d(TAG, "Same IP.");
return;
}
mService = serviceInfo;
DiscoveredDevice device = new DiscoveredDevice(mService.getPort(), mService.getHost(), mService.getServiceName(), mService.getServiceType());
deviceManager.addDevice(device);
helperListener.RESOLVE_SUCCESS(serviceInfo);
}
};
}
private void initializeRegistrationListener()
{
mRegistrationListener = new NsdManager.RegistrationListener()
{
#Override
public void onServiceRegistered(NsdServiceInfo serviceInfo)
{
mServiceName = serviceInfo.getServiceName();
helperListener.SERVICE_REGISTERED(serviceInfo);
}
#Override
public void onRegistrationFailed(NsdServiceInfo serviceInfo, int errorCode)
{
helperListener.SERVICE_REGISTRATION_FAILED(serviceInfo, errorCode);
}
#Override
public void onServiceUnregistered(NsdServiceInfo serviceInfo)
{
helperListener.SERVICE_UNREGISTERED(serviceInfo);
}
#Override
public void onUnregistrationFailed(NsdServiceInfo serviceInfo, int errorCode)
{
helperListener.SERVICE_UNREGISTRATION_FAILED(serviceInfo, errorCode);
}
};
}
/**
* To be called after initialize()
*
* #param port
* - the port you would like to register/broadcast the service through.
*/
public void registerService(int port)
{
NsdServiceInfo serviceInfo = new NsdServiceInfo();
serviceInfo.setPort(port);
serviceInfo.setServiceName(mServiceName);
serviceInfo.setServiceType(SERVICE_TYPE);
mNsdManager.registerService(serviceInfo, NsdManager.PROTOCOL_DNS_SD, mRegistrationListener);
}
/**
* Initiate service discovery to browse for instances of a service type. Service discovery consumes network bandwidth and will continue
* until the application calls stopServiceDiscovery(NsdManager.DiscoveryListener).
*/
public void discoverServices()
{
mNsdManager.discoverServices(SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD, mDiscoveryListener);
}
/**
* Stop service discovery initiated with discoverServices(String, int, NsdManager.DiscoveryListener). An active service discovery is
* notified to the application with onDiscoveryStarted(String) and it stays active until the application invokes a stop service
* discovery. A successful stop is notified to with a call to onDiscoveryStopped(String).
*/
public void stopDiscovery()
{
mNsdManager.stopServiceDiscovery(mDiscoveryListener);
}
/**
*
* #return - A class representing service information for network service discovery
*/
public NsdServiceInfo getChosenServiceInfo()
{
return mService;
}
/**
* Unregister a service registered through registerService(NsdServiceInfo, int, NsdManager.RegistrationListener). A successful
* unregister is notified to the application with a call to onServiceUnregistered(NsdServiceInfo).
*/
public void tearDown()
{
if (mNsdManager != null)
{
try
{
mNsdManager.unregisterService(mRegistrationListener);
mNsdManager.stopServiceDiscovery(mDiscoveryListener);
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
/**
*
* #return - the DiscoveredDevicesManager that contains all valid devices which have the appropriate service susally will call this
* after a msg of RESOLVE_SUCCESS
*/
public DiscoveredDevicesManager getDeviceManager()
{
return deviceManager;
}
}
and finally this is the basis of the server
#Override
public void run()
{
try
{
receiverSocket = new ServerSocket(0);
onPortObtained(receiverSocket.getLocalPort());
Log.d(TAG, "run");
while (broadcastConnection)
{
try
{
Socket newConnectionSocket = receiverSocket.accept();
onNewConnection(newConnectionSocket.getRemoteSocketAddress(), newConnectionSocket.getLocalSocketAddress());
// to clarify this line launches a function that starts threads to handle the socket.
recieveConnection(newConnectionSocket);
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
catch (IOException e1)
{
e1.printStackTrace();
}
}
Edit: one more thing, sometimes while running the devices will randomly restart. No common thing causing, other then they are running the app.

With the service discovery being just to difficult to handle, I will build my own discovery by doing a initial ping like so
List<DiscoveredDevice> devices = new ArrayList<DiscoveredDevice>();
for (int i = 0; i < 256; i++)
{
// this hardcoded ip will be variable from the wifi's ip
String ip = "xx.xx.x." + i;
// this socket may be forever hard coded unless i find a better way. :(
devices.add(new DiscoveredDevice(32999, ip, "", ""));
}
hitting all devices, registering every device that accepts, and every device that accepts registering it.
On leave it will dispatch a command to be removed from every devices queue, and upon trying to send a device a connection that does not get accepted it will be removed.
Hackish, but the Android way wasn't working for me :(, and this way works beautifully.

Jini/JavaSpaces discovery error

On this article: http://java.sun.com/developer/technicalArticles/tools/JavaSpaces/ is a tutorial how to run JavaSpaces client. I wrote these classes in Eclipse, started Launch-All script and Run example. It works.
After that I exported these classes into executable jar (JavaSpaceClient.jar) and tried that jar with following command:
java -jar JavaSpaceClient.jar
It works fine, gives me result:
Searching for a JavaSpace...
A JavaSpace has been discovered.
Writing a message into the space...
Reading a message from the space...
The message read is: Здраво JavaSpace свете!
My problem is when I move this jar file on my other LAN computer, it shows me error when I type same command. Here is error:
cica#cica-System-Name:~/Desktop$ java -jar JavaSpaceClient.jar
Searching for a JavaSpace...
Jul 27, 2011 11:20:54 PM net.jini.discovery.LookupDiscovery$UnicastDiscoveryTask run
INFO: exception occurred during unicast discovery to biske-Inspiron-1525:4160 with constraints InvocationConstraints[reqs: {}, prefs: {}]
java.net.UnknownHostException: biske-Inspiron-1525
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:175)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:384)
at java.net.Socket.connect(Socket.java:546)
at java.net.Socket.connect(Socket.java:495)
at com.sun.jini.discovery.internal.MultiIPDiscovery.getSingleResponse(MultiIPDiscovery.java:134)
at com.sun.jini.discovery.internal.MultiIPDiscovery.getResponse(MultiIPDiscovery.java:75)
at net.jini.discovery.LookupDiscovery$UnicastDiscoveryTask.run(LookupDiscovery.java:1756)
at net.jini.discovery.LookupDiscovery$DecodeAnnouncementTask.run(LookupDiscovery.java:1599)
at com.sun.jini.thread.TaskManager$TaskThread.run(TaskManager.java:331)
I just writes "Searching for JavaSpace..." and after a while prints these error messages.
Can someone help me with this error?
EDIT:
For discovery I am using LookupDiscovery class I've found on Internet:
import java.io.IOException;
import java.rmi.RemoteException;
import net.jini.core.lookup.ServiceRegistrar;
import net.jini.core.lookup.ServiceTemplate;
import net.jini.discovery.LookupDiscovery;
import net.jini.discovery.DiscoveryListener;
import net.jini.discovery.DiscoveryEvent;
/**
A class which supports a simple JINI multicast lookup. It doesn't register
with any ServiceRegistrars it simply interrogates each one that's
discovered for a ServiceItem associated with the passed interface class.
i.e. The service needs to already have registered because we won't notice
new arrivals. [ServiceRegistrar is the interface implemented by JINI
lookup services].
#todo Be more dynamic in our lookups - see above
#author Dan Creswell (dan#dancres.org)
#version 1.00, 7/9/2003
*/
public class Lookup implements DiscoveryListener {
private ServiceTemplate theTemplate;
private LookupDiscovery theDiscoverer;
private Object theProxy;
/**
#param aServiceInterface the class of the type of service you are
looking for. Class is usually an interface class.
*/
public Lookup(Class aServiceInterface) {
Class[] myServiceTypes = new Class[] {aServiceInterface};
theTemplate = new ServiceTemplate(null, myServiceTypes, null);
}
/**
Having created a Lookup (which means it now knows what type of service
you require), invoke this method to attempt to locate a service
of that type. The result should be cast to the interface of the
service you originally specified to the constructor.
#return proxy for the service type you requested - could be an rmi
stub or an intelligent proxy.
*/
Object getService() {
synchronized(this) {
if (theDiscoverer == null) {
try {
theDiscoverer =
new LookupDiscovery(LookupDiscovery.ALL_GROUPS);
theDiscoverer.addDiscoveryListener(this);
} catch (IOException anIOE) {
System.err.println("Failed to init lookup");
anIOE.printStackTrace(System.err);
}
}
}
return waitForProxy();
}
/**
Location of a service causes the creation of some threads. Call this
method to shut those threads down either before exiting or after a
proxy has been returned from getService().
*/
void terminate() {
synchronized(this) {
if (theDiscoverer != null)
theDiscoverer.terminate();
}
}
/**
Caller of getService ends up here, blocked until we find a proxy.
#return the newly downloaded proxy
*/
private Object waitForProxy() {
synchronized(this) {
while (theProxy == null) {
try {
wait();
} catch (InterruptedException anIE) {
}
}
return theProxy;
}
}
/**
Invoked to inform a blocked client waiting in waitForProxy that
one is now available.
#param aProxy the newly downloaded proxy
*/
private void signalGotProxy(Object aProxy) {
synchronized(this) {
if (theProxy == null) {
theProxy = aProxy;
notify();
}
}
}
/**
Everytime a new ServiceRegistrar is found, we will be called back on
this interface with a reference to it. We then ask it for a service
instance of the type specified in our constructor.
*/
public void discovered(DiscoveryEvent anEvent) {
synchronized(this) {
if (theProxy != null)
return;
}
ServiceRegistrar[] myRegs = anEvent.getRegistrars();
for (int i = 0; i < myRegs.length; i++) {
ServiceRegistrar myReg = myRegs[i];
Object myProxy = null;
try {
myProxy = myReg.lookup(theTemplate);
if (myProxy != null) {
signalGotProxy(myProxy);
break;
}
} catch (RemoteException anRE) {
System.err.println("ServiceRegistrar barfed");
anRE.printStackTrace(System.err);
}
}
}
/**
When a ServiceRegistrar "disappears" due to network partition etc.
we will be advised via a call to this method - as we only care about
new ServiceRegistrars, we do nothing here.
*/
public void discarded(DiscoveryEvent anEvent) {
}
}
My client program tries simply to search for JavaSpaces service write MessageEntry into and then retrieves message and prints it out. Here is client program:
import net.jini.space.JavaSpace;
public class SpaceClient {
public static void main(String argv[]) {
try {
MessageEntry msg = new MessageEntry();
msg.content = "Hello JavaSpaces wordls!";
System.out.println("Searching for JavaSpaces...");
Lookup finder = new Lookup(JavaSpace.class);
JavaSpace space = (JavaSpace) finder.getService();
System.out.println("JavaSpaces discovered.");
System.out.println("Writing into JavaSpaces...");
space.write(msg, null, 60*60*1000);
MessageEntry template = new MessageEntry();
System.out.println("Reading message from JavaSpaces...");
MessageEntry result = (MessageEntry) space.read(template, null, Long.MAX_VALUE);
System.out.println("Message: "+result.content);
} catch(Exception e) {
e.printStackTrace();
}
}
}
And of course this is MessageEntry class:
import net.jini.core.entry.*;
public class MessageEntry implements Entry {
public String content;
public MessageEntry() {
}
public MessageEntry(String content) {
this.content = content;
}
public String toString() {
return "MessageContent: " + content;
}
}
EDIT2:
I did discovery on two Windows computers.
After that I tried Windows - Ubuntu combiantion and it doesn't work. Maybe there are some network problems? When I ping each another everything is ok. Maybe there are some DNS issues on Ubuntu..
EDIT3:
Windows - Ubuntu combination works if JavaSpaces service is started up on Windows and client program is on Ubuntu. When I try to do reverse, to run JavaSpaces service on Ubuntu and run client on Windows error occurs.
Obviously there is some problem with Ubuntu. Ubuntu has installed OpenJDK installed by default. I installed Oracle JDK, and set JAVA_HOME and put JAVA_HOME/bin into PATH variable. I wonder maybe there is some problem with different versions of Java, maybe I am not using right one.

It is possible that the service registrar that you are running (on host biske-Inspiron-1525 at port 4160), is discovering it's hostname incorrectly (without domain name) and is therefore sending out the announcements with a short hostname. Therefore, after discovering the service registrar, it is possible that subsequently the client is trying to make a connection to the service registrar it cannot resolve the hostname if it is on a different domain.
To ensure that the service registrar is running with the correct hostname, try starting it with the following command line attribute:
-Dcom.sun.jini.reggie.unicastDiscoveryHost="biske-Inspiron-1525.and.its.domain"

It appears that you are doing unicast discovery to a specific host and port and that you can't look up that host.
Assuming you can resolve the name biske-Inspiron-1525 with DNS try removing the ":4160" part and see if the unicast lookup succeeds then.
Here is an example of the code I use to look up a service. It's a bit more complicated because I implement ServiceDiscoveryListener and handle service discovery that way. I actually keep a list of services and dynamically switch between then when one fails but I stripped that part out of the example. I am also using the Configuration part of Jini which I'll explain afterwards. The service interface I am using here is called "TheService":
public class JiniClient implements ServiceDiscoveryListener {
private TheService service = null;
private Class[] serviceClasses;
private ServiceTemplate serviceTemplate;
public JiniClient(String[] configFiles) throws ConfigurationException {
Configuration config = ConfigurationProvider.getInstance(configFiles,
getClass().getClassLoader());
// Set the security manager
System.setSecurityManager(new RMISecurityManager());
// Define the service we are interested in.
serviceClasses = new Class[] {TheService.class};
serviceTemplate = new ServiceTemplate(null, serviceClasses, null);
// Build a cache of all discovered services and monitor changes
ServiceDiscoveryManager serviceMgr = null;
DiscoveryManagement mgr = null;
try {
mgr = (DiscoveryManagement)config.getEntry(
getClass().getName(), // component
"discoveryManager", // name
DiscoveryManagement.class); // type
if (null == mgr) {
throw new ConfigurationException("entry for component " +
getClass().getName() + " name " +
"discoveryManager must be non-null");
}
} catch (Exception e) {
/* This will catch both NoSuchEntryException and
* ConfigurationException. Putting them both
* below just to make that clear.
*/
if( (e instanceof NoSuchEntryException) ||
(e instanceof ConfigurationException)) {
// default value
try {
System.err.println("Warning, using default multicast discover.");
mgr = new LookupDiscoveryManager(LookupDiscovery.ALL_GROUPS,
null, // unicast locators
null); // DiscoveryListener
} catch(IOException ioe) {
e.printStackTrace();
throw new RuntimeException("Unable to create lookup discovery manager: " + e.toString());
}
}
}
try {
serviceMgr = new ServiceDiscoveryManager(mgr, new LeaseRenewalManager());
} catch (IOException e) {
e.printStackTrace();
throw new RuntimeException("Unable to create service discovery manager: " + e.toString());
}
try {
serviceMgr.createLookupCache(serviceTemplate,
null, // no filter
this); // listener
} catch(Exception e) {
e.printStackTrace();
throw new RuntimeException("Unable to create serviceCache: " + e.getMessage());
}
}
public void serviceAdded(ServiceDiscoveryEvent evt) {
/* Called when a service is discovered */
ServiceItem postItem = evt.getPostEventServiceItem();
//System.out.println("Service appeared: " +
// postItem.service.getClass().toString());
if(postItem.service instanceof TheService) {
/* You may be looking for multiple services.
* The serviceAdded method will be called for each
* so you can use instanceof to figure out if
* this is the one you want.
*/
service = (TheService)postItem.service;
}
}
public void serviceRemoved(ServiceDiscoveryEvent evt) {
/* This notifies you of when a service goes away.
* You could keep a list of services and then remove this
* service from the list.
*/
}
public void serviceChanged(ServiceDiscoveryEvent evt) {
/* Likewise, this is called when a service changes in some way. */
}
The Configuration system allows you to dynamically configure the discovery method so you can switch to discover specific unicast systems or multicast without changing the app. Here is an example of a unicast discovery configuration file that you could pass to the above objects constructor:
import net.jini.core.discovery.LookupLocator;
import net.jini.discovery.LookupDiscoveryManager;
import net.jini.discovery.LookupDiscovery;
com.company.JiniClient {
discoveryManager = new LookupDiscoveryManager(
LookupDiscovery.ALL_GROUPS,
new LookupLocator[] { new LookupLocator("jini://biske-Inspiron-1525.mycompany.com")},
null,
this); // the current config
}

I found solution! That was dns issue. On Ubuntu my /etc/hosts file was:
192.168.1.3 biske-Inspiron-1525 # Added by NetworkManager
127.0.0.1 localhost.localdomain localhost
::1 biske-Inspiron-1525 localhost6.localdomain6 localhost6
127.0.1.1 biske-Inspiron-1525
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
I've just removed line 127.0.1.1 biske-Inspiron-1525 and now it works fine.
Little thing was destroyed million of my nerves :)

Get outgoing IP address in Java RMI

In my java RMI application, I can have instances that behave as servers both locally and on different hosts. In the latter case, how can I get my outgoing IP address so that I can set it as the argument of system property java.rmi.server.hostName?
Right now it's hard wired, but that's not a desirable solution.

You can use the classic Java way:
try {
InetAddress addr = InetAddress.getLocalHost();
// Get IP Address
byte[] ipAddr = addr.getAddress();
// Get hostname
String hostname = addr.getHostName();
} catch (UnknownHostException e) {
}

The following will display all available non-loopback IPv4 adresses on a host. You can easily adapt it to get IPv6 addresses as well.
public static void main(String...args) {
List<InetAddress> addresses = getNonLocalIPV4Addresses();
for (InetAddress addr: addresses) {
System.out.println("address: " + addr.getHostAddress());
}
}
/**
* Get a list of all known non-local IP v4 addresses for the current host.
* #return a List of <code>InetAddress</code>, may be empty but never null.
*/
public static List<InetAddress> getNonLocalIPV4Addresses() {
return getIPAddresses(new InetAddressFilter() {
public boolean accepts(InetAddress addr) {
return (addr instanceof Inet4Address)
&& !(addr.isLoopbackAddress()) || "localhost".equals(addr.getHostName()));
}
});
}
/**
* Get a list of all known IP addresses for the current host,
* according to the specified filter.
* #param filter filters out unwanted addresses.
* #return a List of <code>InetAddress</code>, may be empty but never null.
*/
public static List<InetAddress> getIPAddresses(InetAddressFilter filter) {
List<InetAddress> list = new ArrayList<InetAddress>();
try {
Enumeration<NetworkInterface> interfaces =
NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
NetworkInterface ni = interfaces.nextElement();
Enumeration<InetAddress> addresses = ni.getInetAddresses();
while (addresses.hasMoreElements()) {
InetAddress addr = addresses.nextElement();
if ((filter == null) || filter.accepts(addr)) list.add(addr);
}
}
} catch(Exception e) {
e.printStackTrace();
}
return list;
}
/**
* Filter interface for the methods discovering available IP addresses.
*/
public interface InetAddressFilter {
/**
* Determine whether the specified address is accepted.
* #param addr the address to check.
* #return true if the address is accepted, false otherwise.
*/
boolean accepts(InetAddress addr);
}

I don't understand why you think you need this. The source-address in outgoing stubs is set to the host's IP address automatically. The only time you need to set this property is if the default setting isn't correct: e.g. if you have multiple NICs and only want to export via one, or if you have the Linux misconfiguration that maps your hostname to 127.0.0.1 instead of your IP address.