rmi远程对象调用错误
String url="rmi://localhost/";
System.setSecurityManager(new RMISecurityManager());
Context namingContext=new InitialContext();
User u=(User)namingContext.lookup(url+"User");
Register reg=(Register)Naming.lookup(url+"Register");

报错：javax.naming.NameNotFoundException: User
at com.sun.jndi.rmi.registry.RegistryContext.lookup(RegistryContext.java:99)
at com.sun.jndi.toolkit.url.GenericURLContext.lookup(GenericURLContext.java:185)
at javax.naming.InitialContext.lookup(InitialContext.java:392)
at RegisterClient.<init>(RegisterClient.java:16)
at Client$1.actionPerformed(Client.java:102)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6038)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
at java.awt.Component.processEvent(Component.java:5803)
at java.awt.Container.processEvent(Container.java:2058)
at java.awt.Component.dispatchEventImpl(Component.java:4410)
at java.awt.Container.dispatchEventImpl(Container.java:2116)
at java.awt.Component.dispatchEvent(Component.java:4240)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916)
at java.awt.Container.dispatchEventImpl(Container.java:2102)
at java.awt.Window.dispatchEventImpl(Window.java:2429)
at java.awt.Component.dispatchEvent(Component.java:4240)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)


------解决方案--------------------
我觉得你没注册对
服务端

Java code

try {
    IHello h=new Hello();
    LocateRegistry.createRegistry(8888);
    Naming.bind("rmi://localhost:8888/RHello",h);
} catch (RemoteException e) {
    e.printStackTrace();
} catch (MalformedURLException e) {
    e.printStackTrace();
} catch (AlreadyBoundException e) {
    e.printStackTrace();
}