RMI学习

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package rmi;

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

public interface MyService extends Remote {
  void sayHi(String name) throws RemoteException;
}
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package rmi;

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

public class MyServiceImpl extends UnicastRemoteObject implements MyService {

  private static final long serialVersionUID = -8550790423811608199L;

  protected MyServiceImpl() throws RemoteException {
    super();
  }

  public void sayHi(String name) {
    System.out.println("hello " + name);
  }

}
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package rmi;

import java.net.MalformedURLException;
import java.rmi.Naming;
import java.rmi.RMISecurityManager;
import java.rmi.RemoteException;

public class RmiServer {
  public static void main(String[] args) {
    if (System.getSecurityManager() == null) {
      System.setSecurityManager(new RMISecurityManager());
    }

    // String server = "0.0.0.0";
    String server = "10.13.139.98";
    String rmiPort = "2012";
    System.out.println("starting server " + server);
    try {
      Naming.rebind("rmi://" + server + ":" + rmiPort + "/MyService",
          new MyServiceImpl());
    } catch (RemoteException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (MalformedURLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
}
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package rmi;

import java.net.MalformedURLException;
import java.rmi.Naming;
import java.rmi.NotBoundException;
import java.rmi.RemoteException;

public class Client {
  public static void morning() {
    String server = "10.13.139.100";
    String rmiPort = "2012";
    try {
      MyService myService = (MyService) Naming.lookup("rmi://" + server
          + ":" + rmiPort + "/MyService");
      System.out.println("myService = " + myService);
      myService.sayHi("Forest, Good morning!");
    } catch (MalformedURLException e) {
      e.printStackTrace();
    } catch (RemoteException e) {
      e.printStackTrace();
    } catch (NotBoundException e) {
      e.printStackTrace();
    }
  }

  public static void main(String[] args) {
    morning();
  }
}

my.policy

codeBase "file:///C:/workspace/rmi/bin/*"{
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  permission java.net.SocketPermission "0.0.0.0:2012", "connect,resolve";
};

Run commands,

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C:\j2sdk1.4.2_10\bin\rmic.exe rmi.MyServiceImpl

rmiregistry.exe 2012

java.exe -Djava.rmi.server.hostname=10.13.139.98 -Djava.rmi.server.codebase=file:///C:/workspace/rmi/bin/ -Djava.security.policy=my.policy -cp . rmi.RmiServer

java.exe -cp . rmi.Client

注意：

  1. 如果机器上有多个IP，可以使用java.rmi.server.hostname指定其中一个，如果打印lookup后的对象，会看到MyServiceImpl_Stub[RemoteStub [ref: [endpoint:10.13.139.98:1085,objID:[f72617:1380931e011:-8000, 0]]]]
  2. java.rmi.server.codebase=file:///C:/workspace/rmi/bin/，windows下file后要有3个/，和最后要有个/
  3. my.policy中的*，代表该目录下的所有全限定类拥有权限，是classpath的路径，而不是在.class的目录

Reference

http://docs.oracle.com/javase/1.4.2/docs/guide/rmi/getstart.doc.html