sivaramaiah - Record 1

Record1:1.Communication:
Create a server that accepts the requests from client and client displays the server system information
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1. Interface program comm.java
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import java.rmi.*;

public interface comm extends Remote
{
String showInfo() throws RemoteException;
}

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Program2: Implementation commImp.java
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import java.rmi.*;
import java.rmi.server.*;

public class commImp extends UnicastRemoteObject implements comm
{
public commImp(String strInfo) throws RemoteException
{
  Info = strInfo;
}

public String showInfo() throws RemoteException
{
  return "Message from commImp : "+Info;
}
private String Info;

}

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Program 3: Server program              commServer.java
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import java.rmi.*;
import java.rmi.server.*;

public class commServer
{
public static void main(String[] args)
{
  try
  {
  System.out.print("Constructing Server Implementation...");
  commImp cimp1 = new commImp("This is Developed By Raja");
  commImp cimp2 = new commImp("And it is an RMI Example.");
  System.out.print("Done!nBinding Server Implementation...");

Naming.rebind("author",cimp1);
Naming.rebind("about",cimp2);

  System.out.print("Done!nWaiting for Invocations from client...n");
  }
  catch(Exception e)
  { System.out.print("nError Generated in commServer : "+e.toString()+"n");
  }
}
}

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Program 4: Client program commClient.java
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import java.rmi.*;
import java.rmi.server.*;
import sun.applet.*;

public class commClient
{
public static void main(String[] args)
{
System.setSecurityManager(new RMISecurityManager());

  try
  {
  System.out.print("Naming.lookup for Bindings...");
  comm com1 = (comm) Naming.lookup("author");
  comm com2 = (comm) Naming.lookup("about");
  System.out.print("Done!n");
  System.out.print("Info from author object: "+com1.showInfo()+"n");
  System.out.print("Info from about object: "+com2.showInfo()+"n");
  }
  catch(Exception e)
  { System.out.print("Error Generated in commServer : "+e.toString()+"n");
  }
System.exit(0);
}
}

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Program 5: Show bings class showBindings.java
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import java.rmi.*;
import java.rmi.server.*;

public class showBindings
{
public static void main(String[] args)
{
  try
  {
   String[] bindings = Naming.list("");
   for(int i=0;i<bindings.length;i++)
   System.out.println("Binding ["+(i+1)+"] => "+bindings[i]);
  }
  catch(Exception e)
  { System.out.println("Error in showBindings : "+e.toString()); }

}
}

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Program 6: client.policy
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grant
{
permission java.net.SocketPermission
"*:1024-65335","connect";
};

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How to run the program
________________________________________

1. compile all java files

javac *.java

2. use RMICompiler to create stubs & skeletons of Implementations

rmic commImp

3. run rmiregistry

start rmiregistry

4. create policy file with following contents

client.policy
~~~~~~~~~~~~~

grant
{
permission java.net.SocketPermission
"*:1024-65335","connect";
};

5. run server

java commServer

6. run client with policy created in step 4.

java -Djava.security.policy=client.policy commClient