java - 如何为 RMI 注册表设置自定义端口？

Question

在我的 RMI 程序中，我想在端口 8080 上设置 RMI 注册表，但是当我这样做时，出现异常。

这是我的服务器代码

public class Server {
    public static void main(String[] args) {
        try {
            LocateRegistry.createRegistry(8080);
            MathServerImpl mathServer = new MathServerImpl();
            Naming.rebind("MathServer", mathServer);
            System.out.println("Math Server has started and is running");
        } catch (RemoteException | MalformedURLException e) {
            System.out.println(e.getMessage());
            e.printStackTrace();
        }
    }
}

该代码在端口 1099 上正常工作，据我所知，这是它的默认端口，但在这种情况下，它给了我一个 java.net.ConnectException，这是日志。

java.rmi.ConnectException: Connection refused to host: 10.100.25.173; nested exception is: 
    java.net.ConnectException: Connection refused
    at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:619)
    at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:216)
    at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:202)
    at sun.rmi.server.UnicastRef.newCall(UnicastRef.java:341)
    at sun.rmi.registry.RegistryImpl_Stub.rebind(Unknown Source)
    at java.rmi.Naming.rebind(Naming.java:177)
    at server.Server.main(Server.java:16)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: java.net.ConnectException: Connection refused
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:579)
    at java.net.Socket.connect(Socket.java:528)
    at java.net.Socket.<init>(Socket.java:425)
    at java.net.Socket.<init>(Socket.java:208)
    at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:40)
    at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:147)
    at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:613)
    ... 11 more

Answer 1

您正在端口 8080 上创建注册表，但随后尝试 rebind您的对象位于端口 1099 上的默认注册表中。您需要:

• 将完整 URL 传递至 Naming.rebind包括端口号，即 //localhost:8080/MathServer或
• 保存对 Registry 的引用LocateRegistry.createRegistry 返回的对象并使用该注册表的实例方法而不是 Naming 的静态方法来绑定(bind)对象。

同样，您需要使用完整的 //localhost:8080/MathServer当您的客户 lookup 时，在您的客户中填写 URL 表单对象，以确保它们正在与正确的注册表进行通信。