Question

我正在尝试学习java中的rmi概念。我成功地在我的机器上运行它并尝试在两台机器上运行但是失败了。 Server.java有

System.setSecurityManager(new RMISecurityManager());
        Addition Hello = new Addition();    
        Registry registry = LocateRegistry.createRegistry(5432);
        //Addition stub = (Addition) UnicastRemoteObject.exportObject(Hello,6789);
        registry.rebind("lookupthis", Hello);
        System.out.println("Addition Server is ready.");

Client.java有

Registry reg=LocateRegistry.getRegistry("[ip of server]",5432);
            hello = (AdditionalInterface)Naming.lookup("lookupthis");
            int result=hello.Add(9,10);
            System.out.println("Result is :"+result);

我必须做出哪些改变才能让它适用于两台机器。

请帮助我，提前致谢

Answer 1

而不是“localhost”在RMI服务器的RMI主机中使用“0.0.0.0”。

<强> EDIT1

以下是另一组更改：

在您希望服务器收听LocateRegistry.createRegistry(port)
您的RMI课程Addition应该是可序列化的（通过UnicastRemoteObject实现）
RMI方法应在其签名中抛出RemoteException。
RMI客户端应该知道远程计算机的名称/端口（在本例中为box01 / 1091）。

另请注意，您选择的端口不应已被任何其他服务占用。例如端口1099。

以下是有效的代码：

<强> AdditionalInterface.java

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface AdditionalInterface extends Remote {
    public int Add(int a, int b) throws RemoteException;
}

<强> Addition.java

import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class Addition extends UnicastRemoteObject implements
        AdditionalInterface {
    private static final long serialVersionUID = 1L;

    public Addition() throws RemoteException {
        // TODO Auto-generated constructor stub
    }

    public int Add(int a, int b) {
        return a + b;
    }
}

<强> AdditionServer.java

import java.net.MalformedURLException;
import java.rmi.Naming;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;

public class AdditionServer {
    public static void main(String[] argv) throws RemoteException {
        Addition Hello = new Addition();

        int port = 1091;

        try { // special exception handler for registry creation
            LocateRegistry.createRegistry(port);
            System.out.println("java RMI registry created.");
        } catch (RemoteException e) {
            // do nothing, error means registry already exists
            System.out.println("java RMI registry already exists.");
        }

        String hostname = "0.0.0.0";

        String bindLocation = "//" + hostname + ":" + port + "/Hello";
        try {
            Naming.bind(bindLocation, Hello);
            System.out.println("Addition Server is ready at:" + bindLocation);
        } catch (RemoteException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (Exception e) {
            System.out.println("Addition Serverfailed: " + e);
        }
    }
}

<强> AdditionClient

import java.net.MalformedURLException;
import java.rmi.*;

public class AdditionClient {
    public static void main(String[] args) {
        String remoteHostName = "box01";
        int remotePort = 1091;
        String connectLocation = "//" + remoteHostName + ":" + remotePort
                + "/Hello";

        AdditionalInterface hello = null;
        try {
            System.out.println("Connecting to client at : " + connectLocation);
            hello = (AdditionalInterface) Naming.lookup(connectLocation);
        } catch (MalformedURLException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (RemoteException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (NotBoundException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        int result = 0;
        try {
            result = hello.Add(9, 10);
        } catch (RemoteException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        System.out.println("Result is :" + result);

    }
}

包含2台通过LAN连接的机器的rmi程序示例

1 个答案: