Learning Java Program

RMI Fibonacci Program


FIBONACCI SERVER :

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

public class FibonacciServer
{
public static void main(String[] args)
{
try
{
FibonacciImpl f=new FibonacciImpl();
Naming.rebind(“fibonacci”,f);
System.out.println(“Fibonacci server ready.”);
}
catch(RemoteException re)
{
System.out.println(“Exception in FibonacciImpl.main: ”+re);
}
catch(MalformedURLException e)
{
System.out.println(“Malformed URL Exception ”+e);
}
}
}


FIBONACCI INTERFACE :

import java.rmi.*;
import java.math.BigInteger;

public interface Fibonacci extends Remote
{
public BigInteger getFibonacci(int n) throws RemoteException;
public BigInteger getFibonacci(BigInteger n) throws RemoteException;
}


FIBONACCI CLIENT :

import java.rmi.*;
import java.net;
import java.math.BigInteger;

public class FibonacciClient
{
public static void main(String args[])
{
if(args.length = = 0 || !args[0].startsWith(“rmi:”))
{
System.err.println(“Usage:java Fibonacci client rmi://host.domain:port/fibonacci number”);
return();
}
try
{
Object o = Naming.lookup(args[0]);
Fibonacci calculator = (Fibonacci)o;
for(int i=1;i<args.length;i++)
{
try
{
BigInteger index = new BigInteger (args[i]);
BigInteger f = calculator.getFibonacci(index);
System.out.println(“The ”+args[i]+” Fibonacci number is “+f);
}
catch(NumberFormatException e)
{
System.err.println(args[i]+”is not an integer.”);
}
}
}
catch(MalformedURLException e)
{
System.err.println(args[0]+” is not a valid RMI URL.”);
}
catch(RemoteException e)
{
System.out.println(“Remote object threw exception ”+e);
}
catch(NotBoundException e)
{
System.err.println(“Could not find the requested remote object on server.”);
}
}
}


FIBONACCI IMPLEMENATATION :

import java.rmi.*;
import java.rmi.server.UnicastRemoteObject
import java.math.BigInteger;

public class FibonacciImpl implements Fibonacci
{
public FibonacciImpl() throws RemoteException
{
UnicastRemoteObject.exportObject(this);
}

public BigInteger getFibonacci(int n) throws RemoteException
{
return this.getFibonacci(new BigInteger(Long.toString(n)));
}

public BigInteger getFibonacci (BigInteger n) throws RemoteException
{
System.out.println(“Calculating the ”+n+”the Fibonacci number.”);
BigInteger zero=new BigInteger(“0”);
BigInteger one=new BigInteger(“1”);
if(n.equals(zero))
return zero;
if(n.equals(one))
return one;
BigInteger i=one;
BigInteger a=zero;
BigInteger b=one;
while(i.compareTo(n)= = -1)
{
BigInteger temp = b;
b=b.add(a);
a=temp;
i=i.add(one);
}
return b;
}
}

Here is the code:

FibClient.java

package fib;
import java.rmi.Naming;
import java.io.*;

public class FibClient {

public static void main(String args[]) {
try {
int numFibNum;
String registryURL = "rmi://localhost:1099/fib";
FibInterface h1 = (FibInterface)Naming.lookup(registryURL);
numFibNum = 5;
Fib c = new Fib();
//numFibNum = Integer.parseInt(args[0]);
for (int i=0; i<numFibNum; i++) {
h1.getNextFibNum(c);
System.out.print(h1.getNextFibNum(new Fib())+" ");
}
System.out.println();

for (int i=0; i<numFibNum; i++) {
System.out.print(h1.getNextFibNum(h1.getFib(0,1))+" ");
}
System.out.println();

Fib f = new Fib();
for (int i=0; i<numFibNum; i++) {
System.out.print(h1.getNextFibNum(f)+" ");
}
System.out.println();

FibImpl h2 = new FibImpl();
for (int i=0; i<numFibNum; i++) {
System.out.print(h2.getNextFibNum(f)+" ");
}
System.out.println();

f = new Fib();
for (int i=0; i<numFibNum; i++) {
f = h1.getNextFib(f);
System.out.print(f.getF1()+" ");

}

System.out.println();
} catch(Exception ex) {
ex.printStackTrace();
}
}

}




FibImpl.java

package fib;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
@SuppressWarnings("serial")
public class FibImpl extends UnicastRemoteObject implements FibInterface {
public FibImpl() throws RemoteException {
super();
}
public Fib getFib(int f0, int f1) throws RemoteException {
return new Fib(f0, f1);
}
public int getNextFibNum(Fib f) throws RemoteException {
sleep(500);
int nextFib = f.getF0() + f.getF1();
f.setF0(f.getF1());
f.setF1(nextFib);
return nextFib;
}
public Fib getNextFib(Fib f) throws RemoteException {
sleep(500);
int nextFib = f.getF0() + f.getF1();
f.setF0(f.getF1());
f.setF1(nextFib);
return f;
}
private void sleep(int time) {
try {
Thread.sleep(time);
}
catch(InterruptedException ex) {
ex.printStackTrace();
}
}
}





Fib.java

package fib;
import java.io.Serializable;
@SuppressWarnings("serial")
public class Fib implements Serializable {
private int f0;
private int f1;
public Fib() {
this(0,1);
}
public Fib(int f0, int f1) {
this.f0 = f0;
this.f1 = f1;
}
public int getF0() {
return f0;
}
public void setF0(int f0) {
this.f0 = f0;
}
public int getF1() {
return f1;
}
public void setF1(int f1) {
this.f1 = f1;
}
}



The result will be displayed like below.

1 1 1 1 1

1 1 1 1 1

1 1 1 1 1

1 2 3 5 8

1 2 3 5 8

Here is the code for linux system:

Launching the RMI registry on linux by using the command rmiregistry & and it starts without problems.



FibonacciServer.java:

package myrmifibonacciserver;

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

public class FibonacciServer {
public static void main(String args[]){
try{
Fibonacci fib = new Fibonacci();
Naming.rebind("fibonacci", fib);
System.out.println("Fibonacci Server ready.");
}catch(RemoteException rex){
System.err.println("Exception in Fibonacci.main " + rex);
} catch (MalformedURLException ex) {
System.err.println("MalformedURLException " + ex);
}
}
}



Fibonacci:

package myrmifibonacciserver;

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

public class Fibonacci extends UnicastRemoteObject implements IFibonacci{

private static final long serialVersionUID = -4300545841720809981L;

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

@Override
public BigInteger getFibonacci(int n) throws RemoteException {
return getFibonacci(new BigInteger(Long.toString(n)));
}

@Override
public BigInteger getFibonacci(BigInteger n) throws RemoteException {
System.out.println("Calculating teh " + n + "th Fibonacci number");
BigInteger zero = BigInteger.ZERO;
BigInteger one = BigInteger.ONE;

if(n.equals(zero) || n.equals(one))
return one;

BigInteger current = one;
BigInteger low = one;
BigInteger high = one;
BigInteger temp;

while(current.compareTo(n) == -1){
temp = high;
high = high.add(low);
low = temp;
current = current.add(one);
}
return high;
}

}



IFibonacci:

package myrmifibonacciserver;

import java.math.BigInteger;
import java.rmi.Remote;
import java.rmi.RemoteException;

public interface IFibonacci extends Remote{
public BigInteger getFibonacci(int n) throws RemoteException;
public BigInteger getFibonacci(BigInteger n) throws RemoteException;
}