RMI Server returning a MalformedURL to the client - Resolved

[Alvin Watkins]

I am new to Ubuntu. This RMI code has been working on Windows for months (refactored from earlier code that has worked there for years). When I run on Ubuntu, I get a MalformedURL exception. When I start the server, it comes up fine and it appears my WAR in Tomcat is calling my server and getting a response, but it does not like the response format which I don't know how to change. Here is my server:

	private static transient String name = "name";
	
	public static void main(String[] args) {
		try {
			GameServerInterface server = new GameServer();			
			GameServerInterface stub = (GameServerInterface) 
			 	UnicastRemoteObject.exportObject(server, 1099);
			//Registry registry = LocateRegistry.getRegistry();
			Registry registry = LocateRegistry.createRegistry(1099);
			
			registry.rebind(name, stub);
			
			for(String s:registry.list()) {
				System.out.println("Registry: " + s);				
			}
			
			System.out.println(" server online and " +
					"ready for play.");
		}
		catch(Exception e) {
			e.printStackTrace();
		}
	}

Here is my client:

    private GameServerInterface getRemote() {
        if(gameserver != null) {
            return gameserver;
        }
        try {        	
            //Registry registery = LocateRegistry.getRegistry(8502);
        	Registry registry = LocateRegistry.getRegistry(hostName);
            
        	//error thrown here is a MalformedURL exception??
            gameserver = (GameServerInterface) registry.lookup(name);
        }
        catch(Exception e) {
            e.printStackTrace();
        }
        return gameserver;
    }
    

The error is:

java.rmi.UnmarshalException: error unmarshalling return; nested exception is: 
	java.net.MalformedURLException: no protocol: /usr/local/javaservers/Game-Server-1.0.jar
	at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
	at com.GameServer.server.GameServerClient.getRemote(GameServerClient.java:243)
	at com.GameServer.server.GameServerClient.setAsyncList(GameServerClient.java:167)
	at com.GameServer.web.services.TestServiceAdapter$1.run(TestServiceAdapter.java:118)
Caused by: java.net.MalformedURLException: no protocol: /usr/local/javaservers/GameServer-Server-1.0.jar
	at java.net.URL.<init>(URL.java:583)
	at java.net.URL.<init>(URL.java:480)
	at java.net.URL.<init>(URL.java:429)
	at sun.rmi.server.LoaderHandler.pathToURLs(LoaderHandler.java:770)
	at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:528)
	at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:646)
	at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:311)
	at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStream.java:257)
	at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1549)
	at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1511)
	at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1750)
	at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
	at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
	... 4 more
java.lang.NullPointerException
	at com.GameServer.server.GameServerClient.setAsyncList(GameServerClient.java:168)
	at com.GameServer.web.services.TestServiceAdapter$1.run(TestServiceAdapter.java:118)
java.rmi.UnmarshalException: error unmarshalling return; nested exception is: 
	java.net.MalformedURLException: no protocol: /usr/local/javaservers/GameServer-Server-1.0.jar
	at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
	at com.GameServer.server.GameServerClient.getRemote(GameServerClient.java:243)
	at com.GameServer.server.GameServerClient.getAsyncMessages(GameServerClient.java:155)
	at com.GameServer.web.services.TestServiceAdapter$1.run(TestServiceAdapter.java:128)
Caused by: java.net.MalformedURLException: no protocol: /usr/local/javaservers/GameServer-Server-1.0.jar
	at java.net.URL.<init>(URL.java:583)
	at java.net.URL.<init>(URL.java:480)
	at java.net.URL.<init>(URL.java:429)
	at sun.rmi.server.LoaderHandler.pathToURLs(LoaderHandler.java:770)
	at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:528)
	at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:646)
	at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:311)
	at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStream.java:257)
	at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1549)
	at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1511)
	at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1750)
	at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
	at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
	... 4 more
java.lang.NullPointerException
	at com.GameServer.server.GameServerClient.getAsyncMessages(GameServerClient.java:156)
	at com.GameServer.web.services.TestServiceAdapter$1.run(TestServiceAdapter.java:128)
Exception in thread "Thread-22" java.lang.NullPointerException
	at com.GameServer.web.services.TestServiceAdapter$1.run(TestServiceAdapter.java:131)

[Alvin Watkins]

In case anyone ever has this problem... This was purely my ignorance with dealing with Unix type commands.

When you run a RMI server, you have to create a policy file. You also have to do a few other things before you 'java' your server.jar. Consider the codebase param... It is usually on the command line with your other params and defined such as -"Djava.rmi.server.codebase=%pathtocodebase%server.jar" (without the quotes). In Linux, that has to be appended with the word "file:" such as -Djava.rmi.server.codebase=file:%pathtocodebase%server.jar.

Sheesh. Finally back live.