HACKING TRICKS

Simple Calculator in Java Using Remote Method Invocation


This is a java program for simple arithmetic calculationsusing the principles of Remote Method Invocation (RMI). See Code......


CODE

//mathServer//
import java.rmi.*;
import java.rmi.Naming.*;
import java.rmi.server.*;
import java.rmi.registry.*;
import java.net.*;
import java.util.*;


interface mathInterface extends Remote
{
 public  add(int a,int b) throws RemoteException;
 public int subt(int a,int b) throws RemoteException;
 public int mult(int a,int b) throws RemoteException;
 public int div(int a,int b) throws RemoteException;
}


public class mathServer extends UnicastRemoteObject implements
mathInterface
{
public mathServer() throws RemoteException
{
System.out.println("Initializing Server");
    }
    public int add(int a,int b)
    {
return(a+b);
}
public int subt(int a,int b)
   {
return(a-b);
}
public int mult(int a,int b)
   {
return(a*b);
}
public int div(int a,int b)
   {
return(a/b);
}
public static void main(String args[])
{
try
{
mathServer ms=new mathServer();
java.rmi.Naming.rebind("MathServ",ms);
System.out.println("Server Ready");
   }
   catch(RemoteException RE)
   {
System.out.println("Remote Server Error:"+ RE.getMessage());
System.exit(0);
}
catch(MalformedURLException ME)
{
System.out.println("Invalid URL!!");
}
}
}






//mathClient//
import java.rmi.*;
import java.rmi.registry.*;
import java.awt.*;
import java.awt.event.*;
public class mathClient extends Frame implements ActionListener
{
Button B1=new Button("Sum");
Button B2=new Button("Subtract");
Button B3=new Button("Multiply");
Button B4=new Button("Divide");
Label l1=new Label("Number 1");
Label l2=new Label("Number 2");
Label l3=new Label("Result");
TextField t1=new TextField(20);
TextField t2=new TextField(20);
TextField t3=new TextField(20);
public mathClient()
{
super("Calculator");
setLayout(null);
l1.setBounds(20,50,55,25);
add(l1);
l2.setBounds(20,100,55,25);
add(l2);
l3.setBounds(20,150,55,25);
add(l3);
t1.setBounds(150,50,100,25);
add(t1);
t2.setBounds(150,100,100,25);
add(t2);
t3.setBounds(150,150,100,25);
add(t3);
B1.setBounds(20,200,80,25);
add(B1);
B2.setBounds(100,200,80,25);
add(B2);
B3.setBounds(180,200,80,25);
add(B3);
B4.setBounds(260,200,80,25);
add(B4);
B1.addActionListener(this);
B2.addActionListener(this);
B3.addActionListener(this);
B4.addActionListener(this);
addWindowListener(
new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
);
}
     public void actionPerformed(ActionEvent AE)
     {
if(AE.getSource()==B1)
{
sum();
}
else if(AE.getSource()==B2)
{
subt();
}
else if(AE.getSource()==B3)
{
mult();
}
else if(AE.getSource()==B4)
{
div();
    }
}
public void sum()
{
int i=Integer.parseInt(t1.getText());
int j=Integer.parseInt(t2.getText());
int val;
try
{
String ServerURL="MathServ";
mathInterface MI=(mathInterface)Naming.lookup(ServerURL);
val=MI.add(i,j);
t3.setText(""+val);
}
catch(Exception ex)
{
System.out.println("Exception:"+ex);
}
}
public void subt()
{
int i=Integer.parseInt(t1.getText());
int j=Integer.parseInt(t2.getText());
int val;
try
{
String ServerURL="MathServ";
mathInterface MI=(mathInterface)Naming.lookup(ServerURL);
val=MI.subt(i,j);
t3.setText(""+val);
}
catch(Exception ex)
{
System.out.println("Exception:"+ex);
}
}
public void mult()
{
int i=Integer.parseInt(t1.getText());
int j=Integer.parseInt(t2.getText());
int val;
try
{
String ServerURL="MathServ";
mathInterface MI=(mathInterface)Naming.lookup(ServerURL);
val=MI.mult(i,j);
t3.setText(""+val);
}
catch(Exception ex)
{
System.out.println("Exception:"+ex);
}
}
public void div()
{
int i=Integer.parseInt(t1.getText());
int j=Integer.parseInt(t2.getText());
int val;
try
{
String ServerURL="MathServ";
mathInterface MI=(mathInterface)Naming.lookup(ServerURL);
val=MI.div(i,j);
t3.setText(""+val);
}
catch(Exception ex)
{
System.out.println("Exception:"+ex);
}
}
public static void main(String args[])
{
mathClient MC=new mathClient();
MC.setVisible(true);
MC.setSize(600,500);
};
}