Program 4.1: Retrieve the Student Score from the database. (Use Concept of JDBC and RMI)

File Name: StudentScoreImpl.java

import java.rmi.*;

public interface StudentScoreInterface extends Remote

{

public double findScore(String name)throws RemoteException;

}

File Name:StudentScoreImpl.java

import java.rmi.*;

import java.rmi.server.*;

import java.util.*;

import java.sql.*;

public class StudentScoreImpl extends UnicastRemoteObject implements StudentScoreInterface

{

private PreparedStatement pst;

public StudentScoreImpl()throws RemoteException

{

super(); initilizeDB();

}

protected void initilizeDB()

{

try

{

Class.forName(“com.mysql.jdbc.Driver”); Connection

con=DriverManager.getConnection(“jdbc:mysql://localhost:3306/symca”, “root”, “”);

pst = con.prepareStatement(“Select * from scores where

Name=?”);

}

catch(Exception e)

{

System.out.println(e);

}

• }
• public double findScore(String name)throws RemoteException
• {
  • double score=-1; try
  • {
    • pst.setString(1, name);
    • ResultSet rs=pst.executeQuery(); if(rs.next())
    • {
      • score=rs.getDouble(“Score”);
    • }
  • }
  • catch(Exception e)
  • {
    • System.out.println(e);
  • }
  • System.out.println(score); return score;
• }

}

File Name: StudentScoreRegister.java

import java.rmi.*;

import java.rmi.registry.*;

public class StudentScoreRegister

{

• public static void main(String[] agrs)
• {
  • try
  • {
    • StudentScoreImpl obj = new StudentScoreImpl(); Registry reg = LocateRegistry.getRegistry(); Naming.rebind(“StudentScoreImpl”,obj);
  • }
  • catch(Exception e)
  • {
  • }
• }

}

File Name: StudentScoreClient.java

import java.rmi.*;

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class StudentScoreClient extends JApplet

{

• private StudentScoreInterface student;
• private JButton getScore = new JButton(“GetSocre”); private JTextField name = new JTextField();
• private JTextField tfscore = new JTextField(); private JLabel lblname = new JLabel(“Name”); private JLabel lblscore = new JLabel(“Score”); public void init()
• {
  • try
• {

student = (StudentScoreInterface)Naming.lookup(“StudentScoreImpl”);

• }
  • catch(Exception e)
  • {
  • }
  • JPanel panel = new JPanel(); panel.setLayout(null);
  • lblname.setBounds(20, 20, 80, 34); panel.add(lblname); name.setBounds(100, 20, 160, 34); panel.add(name);
  • lblscore.setBounds(20, 70, 80, 34); panel.add(lblscore); tfscore.setBounds(100, 70, 160, 34); panel.add(tfscore);
  • getScore.setBounds(100, 140, 160, 34); panel.add(getScore, BorderLayout.CENTER); add(panel,BorderLayout.CENTER); getScore.addActionListener(new ActionListener()
  • {
    • public void actionPerformed(ActionEvent ae)
    • {
      • getScore();
    • }
  • }
  • );
• }
• public void getScore()
• {
  • try
  • {
• double score = student.findScore(name.getText()); if(score<0)
• tfscore.setText(“Not Found”);
  • • else tfscore.setText(“”+score);
    • }
  • catch(Exception ex)
  • {
  • }
• }
• public static void main(String[] args)
• {
  • StudentScoreClient applet = new StudentScoreClient(); JFrame frame = new JFrame(); frame.setTitle(“studentscore”); frame.add(applet,BorderLayout.CENTER); frame.setSize(300,240);
  • applet.init(); frame.setVisible(true);
  • }
• }

OUTPUT:

Program 4.2: Using MySQL create Library database. Create table Book

(Book_id, Book_name, Book_author) and retrieve the Book information from Library database using Remote Object Communication concept.

File Name:LibraryInterface.java

import java.rmi.*;

public interface LibraryInterface extends Remote

{

public String[] getData()throws RemoteException;

}

LibraryDB.java

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

public class LibraryDB extends UnicastRemoteObject implements LibraryInterface

{

int count=0;

String str[];

public LibraryDB()throws RemoteException

{

super();

}

public String[] getData()

{

try

{

Class.forName(“com.mysql.cj.jdbc.Driver”);

Connection con=DriverManager.getConnection(“jdbc:mysql://localhost:3306/symca”, “root”, “”); Statement st=con.createStatement();

ResultSet rs=st.executeQuery(“select * from library”);

while(rs.next())

{

count++;

}

str=new String[count];

ResultSet rs1=st.executeQuery(“select * from library”); for(int i=0; i<count; i++)

{

rs1.next(); str[i]=rs1.getString(1);

}

}

catch(Exception e)

{

System.out.println(e);

}

return str;

}

}

File Name:LibraryDBClient.java

import java.rmi.*;

public class LibraryDBClient

{

• public LibraryDBClient()
• {
• try
• {
• LibraryInterface library = (LibraryInterface)Naming.lookup(“LibraryDB”); String[] result=library.getData();
• for (String res: result)
• {
• System.out.println(“
• ----- “+”\n“+”|
• “+res+”\n“+” “);
• }

}

• catch(Exception e)
• {
• System.out.println(e);
• }
• }
• public static void main(String[] args)
• {
• new LibraryDBClient();
• }

}

File Name:LibraryDBRegister.java

import java.rmi.*;

import java.rmi.registry.*; public class LibraryDBRegister

{

• public static void main(String[] agrs)
• {
  • try
  • {
• LibraryDB obj = new LibraryDB();
• Registry reg = LocateRegistry.getRegistry(); Naming.rebind(“LibraryDB”,obj);
• }
• catch(Exception e)
  • {
  • }
• }

}

OUTPUT:

Exercise 1: Using MySQL create Elecrtic_Bill database. Create table Bill (consumer_name, bill_due_date, bill_amount) and retrieve the Bill information from the Elecrtic_Bill database using Remote Object Communication concept.