Java APIs

Hello,

I run the server.java and client.java on ONE PC with the IP *192.168.1.4*
Why do i get this:

Exception in thread "main" java.rmi.ConnectException: Connection refused to host: 192.168.1.4; nested exception is: 
	java.net.ConnectException: Connection refused: connect
	at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
	at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
	at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
	at sun.rmi.server.UnicastRef.newCall(Unknown Source)
	at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
	at Client.main(Client.java:11)
Caused by: java.net.ConnectException: Connection refused: connect
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.PlainSocketImpl.doConnect(Unknown Source)
	at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
	at java.net.PlainSocketImpl.connect(Unknown Source)
	at java.net.SocksSocketImpl.connect(Unknown Source)
	at java.net.Socket.connect(Unknown Source)
	at java.net.Socket.connect(Unknown Source)
	at java.net.Socket.<init>(Unknown Source)
	at java.net.Socket.<init>(Unknown Source)
	at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(Unknown Source)
	at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(Unknown Source)
	... 6 more

public class Client 
{ 
	  public static void main( String[] args ) throws RemoteException, NotBoundException 
	  { 
		    Registry registry = LocateRegistry.getRegistry(); 
		    Adder adder = (Adder) registry.lookup( "Adder" ); 
		    
		    System.out.println( adder.add( 50, 10 ) ); 
	  } 
}

public class Server 
{ 
	  public static void main( String[] args ) throws RemoteException 
	  { 
		    LocateRegistry.createRegistry( Registry.REGISTRY_PORT ); 
		 
		    AdderImpl adder = new AdderImpl(); 
		    Adder stub = (Adder) UnicastRemoteObject.exportObject( adder, 0 ); 
		    RemoteServer.setLog( System.out ); 
		 
		    Registry registry = LocateRegistry.getRegistry(); 
		    registry.rebind( "Adder", stub ); 
		 
		    System.out.println( "Adder angemeldet" );  
	  } 
}

public interface Adder extends Remote 
	{ 
	  int add( int x, int y ) throws RemoteException; 
	  
	  
	}

public class AdderImpl implements Adder 
	{ 
		  public int add( int x, int y ) 
		  { 
		    return x + y; 
		  } 
	}