如何設置RMI注冊的自定義端口？

Question

在我的RMI程序中，我想在端口8080上設置我的RMI注冊表，但是當我這樣做時，出現了異常。

這是我的服務器代碼

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();
        }
    }
}

代碼對於端口1099正常工作，據我所知，它是默認端口，但是在這種情況下，它給了我java.net.ConnectException，這是日志。

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上創建注冊表，但隨后嘗試在端口1099的默認注冊表中rebind對象。您需要執行以下任一操作：

• 將完整的URL傳遞給Naming.rebind包括端口號，即//localhost:8080/MathServer或
• 保存對LocateRegistry.createRegistry返回的Registry對象的引用，並使用該注冊表的實例方法（而不是靜態Naming的靜態方法）綁定該對象

同樣，在客戶端lookup對象時，您將需要在客戶端中使用完整的//localhost:8080/MathServer URL表單，以確保它們正在與正確的注冊表通信。

Answer 2

Naming.rebind("MathServer", mathServer);

更改為

Naming.rebind("//localhost:8080/MathServer", mathServer);

Answer 3

如果您是Linux Ubuntu用戶，則在啟動RMI注冊表時使用命令

rmir​​egistry 8080＆

對於Windows

啟動rmiregistry 8080