sivaramaiah - Record 4

Record 4:Stockmarket:
Create a remote stock server that accepts the company name and gives the share value. Stock client that retrieves the company share value and displays by giving the company name.

-----------------------------------------------------------------------------------------

Program 1: Interface program ShareVal.java

import java.rmi.*;

public interface ShareVal extends Remote
{
public float getShareValue(String Company) throws RemoteException;
}

Program 2: Implementation program ShareValImp.java

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

public class ShareValImp extends UnicastRemoteObject implements ShareVal
{

   public ShareValImp() throws RemoteException
   {
       super();
   }

   public float getShareValue(String Company) throws RemoteException
   {

       byte buffer[] = new byte[2056];
       try
       {
           FileInputStream fis = new FileInputStream("shares.txt");
           int bytes = fis.read(buffer,0,2056);
           try
           {
               String str = new String(buffer,0,bytes,"Default");
               String[] shares = str.split("~");

               for(int i=0;i<shares.length;i++)
               {
                   if(shares[i].trim().compareTo(Company)==0)
                   return(Float.parseFloat(shares[i+1].trim()));
               }

           }
           catch(Exception e)
           { System.out.println("Error, maybe string error :"+e);
           }
       }
       catch(Exception e)
       { System.out.println("Error at ShareValImp : "+e);
       }
   return 0;
   }
}
-------------------------------------------------------------

Program 3: Server program ShareValServer.java

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

public class ShareValServer
{
   public static void main(String[] args)
   {
       try
       {
       System.out.print("Constructing Server Implementation...");
       ShareValImp SV1 = new ShareValImp();

       Naming.rebind("Shares",SV1);

       System.out.print("Done!nWaiting for Invocations from client...n");
       }
       catch(Exception e)
       { System.out.print("Error at ShareValServer : "+e);
       }
   }
}

Program 4: Client program ShareValClient.java

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

public class ShareValClient
{
   public static void main(String[] args)
   {

       try
       {
       System.out.print("Enter Company Name : ");
       DataInputStream dis = new DataInputStream(System.in);
       String coy = dis.readLine();
       System.out.print("Naming.lookup for Bindings...");
       ShareVal SVal = (ShareVal) Naming.lookup("Shares");

       System.out.print("Done!n");

       System.out.println("Company : "+coy+"'s Share value = "+SVal.getShareValue(coy));

       }
       catch(Exception e)
       { System.out.print("Error at ShareValClient : "+e);
       }
   }
}
------------------------------------------------------------
Program 5: text file             shares.txt
------------------------------------------------------------
HCL~125.50~
HP~124.50~
WIPRO~100.25~
SATYAM~99.75~
MICROSOFT~150.50~
IBM~145.75~
SUNMICRO~200.75~
AMD~175.90~
INTEL~180.95
------------------------------------------------------------

Program 6: Show Bindings showBingings.java

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()); }

}

Program 7: clinet.policy clinet.policy

grant

{

permission java.net.SocketPermission

"*:1024-65335","connect";

};

How to run the program

1. compile all java files

javac *.java

2. use RMICompiler to create stubs & skeletons of Implementations

rmic ShareValImp

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 ShareValServer

6. run client with policy created in step 4.

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