The Rmi error in client!

Question

I'm try to write a RMI application in linux
I used the java sample code for beginning !
But It can't run normally.The error is as following :
exception:java.rmi.ConnectException:Connection refused to host:0.0.0.0;nested exception is :java.net.ConnectException: Connection refuse.
Can anyone help me slove the problem.
there are the code .
//Server side
//Lookup.java
import java.rmi.*;
public interface Lookup extends Remote {
public String findInfo(String info)
throws RemoteException;}
//LookupServer.java
//LookupServer.java
import java.io.*;
import java.util.*;
import java.rmi.*;
import java.rmi.server.*;
public class LookupServer extends UnicastRemoteObject implements Lookup{
private Vector save=new Vector();
public LookupServer(String db) throws RemoteException
try {
FileReader fr=new FileReader(db);
BufferedReader br= new BufferedReader(fr);
String s=null;
while((s=br.readLine()) !=null)
save.addElement(s);
fr.close();
catch (Throwable e)
System.err.println("exception\n");
System.exit(1);
public String findInfo(String info)
if(info==null)
return null;
info=info.toLowerCase();
int n=save.size();
for(int i=0;i<n;i++)
String dbs=(String)save.elementAt(i);
if(dbs.toLowerCase().indexOf(info)!=-1)
return dbs;
return null;
public static void main(String args[])
try {
RMISecurityManager security =new RMISecurityManager();
System.setSecurityManager(security);
String db=args[0];
LookupServer server =new LookupServer(db);
Naming.rebind("LookupServer",server);
System.err.println("LookupServer ready ....");
catch(Throwable e)
System.err.println("exception: "+e);
System.exit(1);
//Client Side
//LookupClient.java
import java.rmi.*;
import java.rmi.server.*;
public class LookupClient {
public static void main(String args[])
try{
RMISecurityManager security=new RMISecurityManager();
System.setSecurityManager(security);
String host="localhost";
String server="LookupServer";
String name="rmi://"+host+"/"+server;
Lookup look_obj=(Lookup)Naming.lookup(name);
String results=look_obj.findInfo(args[0]);
if(results==null)
System.err.println("** not found **");
else
System.out.println(results);
catch (Throwable e)
System.err.println("exception: "+e);
System.exit(1);

Answer 1

I am not sure if this will work but try it anyway.
String host="localhost";
instead use...
String host = "127.0.0.1";
in both server and client.
I say this because localhost is resolving to "0.0.0.0" which is not correct. Generally under Unix, you have a file called "hosts" under /etc. This is where you map a server name to the IP. So if you insist on using "localhost" as your server name, make sure you have an entry in this "hosts" file under /etc which is something like...
127.0.0.1 localhost
Then you can refer to the System as "localhost".
Just to making sure - You started your server right - Before starting your client?
Hope to help you solve this problem. Do re-post if the problem continues.
Best Regards,
Manish