java - 如何远程关闭 Java RMI 服务器

Question

我有一个非常简单的 Java RMI 服务器，如下所示:

    import java.rmi.*;
    import java.rmi.server.*;

    public class CalculatorImpl extends UnicastRemoteObject implements Calculator {

        private String mServerName;

        public CalculatorImpl(String serverName) throws RemoteException
        {
            super();
            mServerName = serverName;
        }

        public int calculate(int op1, int op2) throws RemoteException
        {
            return op1 + op2;
        }

        public void exit() throws RemoteException
        {
            try{
                Naming.unbind(mServerName);
                System.out.println("CalculatorServer exiting.");
            }
            catch(Exception e){}

            System.exit(1);
        }

        public static void main(String args[]) throws Exception
        {
            System.out.println("Initializing CalculatorServer.");

            String serverObjName = "rmi://localhost/Calculator";

            Calculator calc = new CalculatorImpl(serverObjName);

            Naming.rebind(serverObjName, calc);

            System.out.println("CalculatorServer running.");
        }
}

当我调用退出方法时，System.exit(1) 抛出以下异常:

CalculatorServer exiting.
java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is:
        java.io.EOFException
        at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:203)
        at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:126)
        at CalculatorImpl_Stub.exit(Unknown Source)
        at CalculatorClient.<init>(CalculatorClient.java:17)
        at CalculatorClient.main(CalculatorClient.java:29)
Caused by: java.io.EOFException
        at java.io.DataInputStream.readByte(DataInputStream.java:243)
        at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:189)
        ... 4 more
[2]+  Exit 1                  java CalculatorImpl

我在这个方法中做错了什么？

Answer 1

如果有人遇到类似问题，我自己想出了答案。这是我的 exit() 方法:

public void exit() throws RemoteException
{
    try{
        // Unregister ourself
        Naming.unbind(mServerName);

        // Unexport; this will also remove us from the RMI runtime
        UnicastRemoteObject.unexportObject(this, true);

        System.out.println("CalculatorServer exiting.");
    }
    catch(Exception e){}
}