Spring：无法从防火墙后面使用 RMI 连接到 JMX 服务器

我的 Spring 应用程序正在 NAT 防火墙 (pfSense) 后面的计算机上运行。机器的内部IP是a.b.c.d，NAT IP 为w.x.y.z

Spring配置的serviceUrl设置为我的内部IP（a.b.c.d) 在港口1100，当我启动应用程序时，我提供以下开关：

 -Dcom.sun.management.jmxremote -Djava.rmi.server.hostname=w.x.y.z -Dcom.sun.management.jmxremote.port=1099 -Dcom.sun.management.jmxremote.local.only=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false

如上图，我设置了-Djava.rmi.server.hostname=w.x.y.z以便能够通过 NAT 连接到应用程序。我在机器的防火墙上也开放了相关端口，并设置了端口转发w.x.y.z:1100 to a.b.c.d:1100

当我尝试使用 jconsole 从网络外部连接到应用程序时w.x.y.z:1100，我得到一个java.io.IOException: jmxrmi

 java.io.IOException: jmxrmi
at sun.tools.jconsole.ProxyClient.checkSslConfig(ProxyClient.java:236)
at sun.tools.jconsole.ProxyClient.<init>(ProxyClient.java:127)
at sun.tools.jconsole.ProxyClient.getProxyClient(ProxyClient.java:483)
at sun.tools.jconsole.JConsole$3.run(JConsole.java:524)
 Caused by: java.rmi.NotBoundException: jmxrmi
at sun.rmi.registry.RegistryImpl.lookup(RegistryImpl.java:136)
at sun.rmi.registry.RegistryImpl_Skel.dispatch(Unknown Source)
at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:409)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:267)
at sun.rmi.transport.Transport$1.run(Transport.java:177)
at sun.rmi.transport.Transport$1.run(Transport.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:556)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:811)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:670)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:275)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:252)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:378)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at sun.tools.jconsole.ProxyClient.checkSslConfig(ProxyClient.java:234)

如果我尝试使用 jconsole 进行连接w.x.y.z:1099，我得到一个java.rmi.ConnectException (Connection refused)。如何将 JMX MBean 暴露在 NATted 防火墙之外？

 java.rmi.ConnectException: Connection refused to host: w.x.y.z; nested exception is: 
java.net.ConnectException: Operation timed out
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.invoke(UnicastRef.java:129)
at javax.management.remote.rmi.RMIServerImpl_Stub.newClient(Unknown Source)
at javax.management.remote.rmi.RMIConnector.getConnection(RMIConnector.java:2373)
at javax.management.remote.rmi.RMIConnector.connect(RMIConnector.java:297)
at sun.tools.jconsole.ProxyClient.tryConnect(ProxyClient.java:355)
at sun.tools.jconsole.ProxyClient.connect(ProxyClient.java:313)
at sun.tools.jconsole.VMPanel$2.run(VMPanel.java:292)
Caused by: java.net.ConnectException: Operation timed out
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)
... 9 more

有趣的是，我可以连接到两个端口（1099 and 1100) on w.x.y.z using telnet.

我的 Spring 配置的相关部分是：

<bean id="registry" class="org.springframework.remoting.rmi.RmiRegistryFactoryBean">
    <property name="port" value="1100" />
</bean>
<bean id="serverConnector" class="org.springframework.jmx.support.ConnectorServerFactoryBean" depends-on="registry">
    <property name="server" ref="mbeanServer" />
    <property name="objectName" value="connector:name=rmi" />
    <property name="serviceUrl" value="service:jmx:rmi://a.b.c.d:1100/jndi/rmi://a.b.c.d:1100/server" />
    <property name="environment">
        <props>
            <prop key="jmx.remote.jndi.rebind">true</prop>
        </props>
    </property>
</bean>
<bean id="mbeanServer" class="org.springframework.jmx.support.MBeanServerFactoryBean">
    <!-- indicate to first look for a server -->
    <property name="locateExistingServerIfPossible" value="true"/>
</bean>

注意：我没有使用任何 servlet 容器。

EDIT：第一个答案为我提供了解决我的具体问题的基础，这可以在第二个答案中看到。

您定义的初始端口com.sun.management.jmxremote.port称为注册​​端口，仅用于启动协商并确定下一个用于“真实”通信的端口。 Java RMI 机制使用动态分配的端口，通常与防火墙不兼容。

Java RMI 连接使用什么端口？

也就是说，对于 JMX 来说，可以解决这个问题

a) 使用系统属性锁定两个端口（需要 Java 7）

com.sun.management.jmxremote.port
com.sun.management.jmxremote.rmi.port

b) 使用自定义代码请求特定端口。看JConsole 通过 ssh 本地端口转发

也可以看看：

• 为什么配置JMX时Java会打开3个端口？
• http://realjenius.com/2012/11/21/java7-jmx-tunneling-freedom/