来自远程机器的 RMI 超时

Question

我可以在同一台机器上使用我的客户端代码连接到 RMI 服务器。但是当我从另一台机器通过互联网访问它时，几分钟后我收到超时异常。

我检查了端口并且正在监听。

java.rmi.ConnectException: Connection refused to host: 11.11.11.11; nested exception is: 
java.net.ConnectException: Connection timed out
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:601)
at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:198)
at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:184)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:110)
at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:178)
at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:132)
at $Proxy0.echoString(Unknown Source)
at client.UseMon.main(UseMon.java:42)
Caused by: java.net.ConnectException: Connection timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at java.net.Socket.connect(Socket.java:478)
at java.net.Socket.<init>(Socket.java:375)
at java.net.Socket.<init>(Socket.java:189)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:22)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:128)
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:595)
... 7 more

我现在应该检查什么。

谢谢。

Answer 1

“...通过另一台机器通过互联网...” - 您的服务器位于路由器后面吗？在这种情况下，您必须转发端口。这可以解释为什么它可以在本地工作但不能远程工作。