在两台linux下架设rmi经常会出现以下异常，Naming.lookup(url)中url的ip地址明明是server端的ip，可返回的信息却是被本机的ip拒绝，确实很怪异，异常如下：
java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is: java.net.ConnectException: Connection refused
解决方法是在server端的代码中添加一行代码：
System.setProperty("java.rmi.server.hostname",server端的ip);//添加这行代码
LocateRegistry.createRegistry(1099);
RemoteImpl service = new RemoteImpl();
Naming.rebind("RmiServer", service);
LocateRegistry.createRegistry(1099);
RemoteImpl service = new RemoteImpl();
Naming.rebind("RmiServer", service);