【发布时间】：2014-09-05 04:33:47
【问题描述】：
我有：
- 要求用户输入以创建新用户的 GUI。
- 一旦点击提交，它会在 AdminModule 类中调用 createPlayer（抛出 RemoteException）。
- 我将参数传递给 AdminInterfaceImplementation（抛出 RemoteException）以调用 PlayersData 类中的另一个方法来创建对象。注意 PlayersData 中的方法没有被调用。
我正在运行 RMI，并使用简单的 println 测试了连接，它工作正常。但是，该方法仍然没有调用。请告知可能是什么问题。
PlayersData 中的方法是否需要抛出 RemoteException 才能工作？
// AdminModule
public static void main(String args[])
{
try {
System.out.println("Hi from AdminModule");
AdminFactory theWorks = (AdminFactory) Naming.lookup("rmi://localhost:13456/AdminInterfaceTest");
myAdminInterface = theWorks.newAdminInterface();
new AdminModule().run();
}
catch (Exception e)
{
System.out.println("catch" + e);
}
}
public void createPlayer(String name, String password, int chips) throws RemoteException
{
String hashedPassword = Utility.getHash(password);
myAdminInterface.createPlayer(name, hashedPassword, chips);
System.out.println ("Create Player from Admin Module: " + name + ", " + hashedPassword + ", " + chips);
}
// AdminInterfaceImplementation
public void createPlayer(String name, String password, int chips) throws RemoteException {
System.out.println ("Create Player from Admin Interface: " + name + ", " + password + ", " + chips); // can display in console
adminModule.test(name, password, chips); //this method doesn't get invoked.
}
//PlayersData - not invoke
public void addPlayer(String name, String password, int chips) {
System.out.println ("Create Player from PlayersData: " + name + ", " + password + ", " + chips);
Player p = new Player (name, password, chips);
playerList.add(p);
JOptionPane.showMessageDialog(null, "Player created successfully", "Display",
JOptionPane.INFORMATION_MESSAGE);
}
更新：
该方法现在被调用但出现以下错误...
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at AdminInterfaceImpl.createPlayer(AdminInterfaceImpl.java:13)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:303)
at sun.rmi.transport.Transport$1.run(Transport.java:159)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:535)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:790)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:649)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at java.lang.Thread.run(Thread.java:695)
at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:142)
at AdminInterfaceImpl_Stub.createPlayer(Unknown Source)
at AdminModule.createPlayer(AdminModule.java:79)
at AdminMenuFrame$6.actionPerformed(AdminMenuFrame.java:198)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
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:6414)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3275)
【问题讨论】：
-
将默认端口更改为 1099 以及如何使用命令行或任何 IDE（Eclipse/NetBeans）来实现它？？？
-
@shekharsuman 使用 1099 时出现连接拒绝错误。我正在使用 Eclipse。
-
看起来在客户端创建了一个
AdminModule实例，成功向服务器发出远程调用。但是服务器在createPlayer()中获得了 NPE。我在猜测第 13 行的内容，但我会说 server 端的adminModule为空。 -
@StuartMarks 谢谢。我在 createPlayer 方法中初始化了类对象，现在没有 NPE 错误。