Java Programming With JDBC ,Client Server , Chat Server ( Chat Room ), RMI

Java DataBase Delete Record.(JDBC)

import java.sql.*;
public class JavaDBDR
{
    public static void main(String args[])
    {
    try
    {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        String url="jdbc:odbc:EmployeesDSN";         //DSN Name
        Connection conn=null;
        conn=DriverManager.getConnection(url,"","");
        Statement s=conn.createStatement();
        s.execute("DELETE FROM EMP WHERE EMPCODE=6");   //EMP DataBase Table Name
        s.execute("select * from EMP");
        ResultSet rs = s.getResultSet();
                  if (rs != null)
        while (rs.next() )
        {
        System.out.println(rs.getString(1)+" "+rs.getString(2)+" "+rs.getString(3)+" "+ rs.getString(4) +" "+ rs.getString(5)+ " "+rs.getString(6) );   
        }
        s.close();
        conn.close();
    }
    catch(Exception ex)
    {
            System.out.println(ex);       
    }
    }
}




Java DataBase insert Record.(JDBC)

import java.sql.*;
public class JavaDBIR
{
    public static void main(String args[])
    {
    try
    {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        String url="jdbc:odbc:EmployeesDSN";
        Connection conn=null;
        conn=DriverManager.getConnection(url,"","");
        Statement s=conn.createStatement();
        s.execute("insert into EMP values(6,'Kamran',10000,'Gulburg','Faisalabad','0300-6602727')");
        s.execute("select * from EMP");
        ResultSet rs = s.getResultSet();
                  if (rs != null)
        while (rs.next() )
        {
                System.out.println(rs.getString(1)+" "+rs.getString(2)+" "+rs.getString(3)+" "+ rs.getString(4) +" "+ rs.getString(5)+ " "+rs.getString(6) );   
        }
        s.close();
        conn.close();
    }
    catch(Exception ex)
    {
            System.out.println(ex);       
    }
    }
}





 Java DataBase insert Record With Create New Table.(JDBC)

import java.sql.*;
public class Test
{
      public static void main(String[] args)
      {
        try {
          Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
          /* the next 3 lines are Step 2 method 2 from above - you could use the direct
          access method (Step 2 method 1) istead if you wanted */
          String dataSourceName = "mdbTEST";
          String dbURL = "jdbc:odbc:" + dataSourceName;
          Connection con = DriverManager.getConnection(dbURL, "","");
          // try and create a java.sql.Statement so we can run queries
          Statement s = con.createStatement();
          s.execute("create table TEST12345 ( column_name integer )"); // create a table
          s.execute("insert into TEST12345 values(1)"); // insert some data into the table
          s.execute("select column_name from TEST12345"); // select the data from the table
          ResultSet rs = s.getResultSet(); // get any ResultSet that came from our query
          if (rs != null) // if rs == null, then there is no ResultSet to view
          while ( rs.next() ) // this will step through our data row-by-row
          {
            /* the next line will get the first column in our current row's ResultSet
            as a String ( getString( columnNumber) ) and output it to the screen */
            System.out.println("Data from column_name: " + rs.getString(1) );
         }
        s.execute("drop table TEST12345");
        s.close(); // close the Statement to let the database know we're done with it
        con.close(); // close the Connection to let the database know we're done with it
    }
    catch (Exception err) {
        System.out.println("ERROR: " + err);
    }
  }
}




Java DataBase Update Record.(JDBC)

import java.sql.*;
public class UpdateData
{
    public static void main(String args[])
    {
    try
    {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        String s="jdbc:odbc:PersonalDSN";   
        Connection c=null;
        c=DriverManager.getConnection(s,"","");
        Statement st=c.createStatement();
        String s2="Select * from Students";       
        st.execute("UPDATE STUDENTS  SET FIRSTNAME='ABRAR' where FIRSTNAME='KAHSIF' AND CITY='LHR'");
        System.out.println("Record has been updated in database successfully");   
        ResultSet rs=st.executeQuery(s2);
        while(rs.next())
        {
            String rn=rs.getString("RegNo");
            String fn=rs.getString("FirstName");
            String ln=rs.getString("LastName");
            String ad=rs.getString("Address");
            String ct=rs.getString("City");
            String cn=rs.getString("ContactNo");
            System.out.println(rn+"  "+fn+"  "+ln+"  "+ad+"  "+ct+"  "+cn);
        }
       
        c.close();
    }
    catch(Exception ex)
    {
            System.out.println(ex);       
    }
    }
}

Java DataBase Select Record.(JDBC)
 import java.sql.*;
public class SelData
{
    public static void main(String args[])
    {
    try
    {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        String s="jdbc:odbc:PersonalDSN";  
        Connection c=null;
        c=DriverManager.getConnection(s,"","");
        Statement st=c.createStatement();
        String sql="SELECT * FROM STUDENTS order by firstname desc";
        ResultSet rs=st.executeQuery(sql);
        while(rs.next())
        {
            String rn=rs.getString("RegNo");
            String fn=rs.getString("FirstName");
            String ln=rs.getString("LastName");
            String ad=rs.getString("Address");
            String ct=rs.getString("City");
            String cn=rs.getString("ContactNo");
            System.out.println(rn+"  "+fn+"  "+ln+"  "+ad+"  "+ct+"  "+cn);
        }
        c.close();
    }
    catch(Exception ex)
    {
            System.out.println(ex);      
    }
    }
}




JAVA CLIENT AND SERVER Programming Using TCP  And  UDP


JAVA CLIENT ,  SERVER Programming Using TCP

 //client side
import java.net.*;
import java.io.*;
public class Client{
    Client(){
        int c=0;
        char ch=' ';
        try{
            Socket ss=new Socket("127.0.0.1",2235);
            InputStream is=ss.getInputStream();
            Thread.sleep(500);
        do{       
            c=is.read();   
            ch=(char)c;
            System.out.print(ch);
        }while(ch!='?');

        }catch(Exception e){}
    }
    public static void main(String as[]){
        Client s=new Client();
    }
}


 // Server side

import java.net.*;
import java.io.*;
public class Server{
    Server(){
        Socket cli=null;
        try{
            String msg="Message from Server ?";
            byte b[]=msg.getBytes();
            ServerSocket ss=new ServerSocket(2235);
            System.out.println("Waiting for Client");
            cli=ss.accept();
            System.out.println("Client Connected "+cli);
            OutputStream os=cli.getOutputStream();
            os.write(b);  
            Thread.sleep(1000);
        }catch(Exception e){}
    }
    public static void main(String as[]){
        Server s=new Server();
    }
}


 JAVA CLIENT ,  SERVER Programming Using UDP

//Client Side

import java.net.*;
import java.io.*;
class DGClient{
    DatagramSocket ds=null;
    DatagramPacket dp=null;
    DGClient(){
    try{
        ds=new DatagramSocket(2235);
        byte b[]=new byte[25];
        while(true){
        dp=new DatagramPacket(b,b.length);
        ds.receive(dp);
        System.out.println(new String(dp.getData()));
        }
    }catch(Exception e){}
    }
    public static void main(String as[]){
        DGClient dg=new DGClient();
    }
}




//Server Side


import java.net.*;
import java.io.*;
class DGServer{
    DatagramSocket ds=null;
    DatagramPacket dp=null;
    InetAddress addr=null;
    String msg="";
    DGServer(){
    try{
        msg="Message from Server";
        addr=InetAddress.getByName("localhost");
        ds=new DatagramSocket();
        byte b[]=msg.getBytes();
        while(true){
            dp=new DatagramPacket(b,b.length,addr,2235);
            ds.send(dp);
        }
    }catch(Exception e){}
    }
    public static void main(String as[]){
        DGServer dg=new DGServer();
    }
}




 Java Chat Server, Client Server

//Server Side 

import java.io.*;
import java.net.*;
public class Provider{
    ServerSocket providerSocket;
    Socket connection = null;
    ObjectOutputStream out;
    ObjectInputStream in;
    String message;
    Provider(){}
    void run()
    {
        try{
            //1. creating a server socket
            providerSocket = new ServerSocket(2004, 10);
            //2. Wait for connection
            System.out.println("Waiting for connection");
            connection = providerSocket.accept();
            System.out.println("Connection received from " + connection.getInetAddress().getHostName());
            //3. get Input and Output streams
            out = new ObjectOutputStream(connection.getOutputStream());
            out.flush();
            in = new ObjectInputStream(connection.getInputStream());
            sendMessage("Connection successful");
            //4. The two parts communicate via the input and output streams
            do{
                try{
                    message = (String)in.readObject();
                    System.out.println("client>" + message);
                    if (message.equals("bye"))
                        sendMessage("bye");
                }
                catch(ClassNotFoundException classnot){
                    System.err.println("Data received in unknown format");
                }
            }while(!message.equals("bye"));
        }
        catch(IOException ioException){
            ioException.printStackTrace();
        }
        finally{
            //4: Closing connection
            try{
                in.close();
                out.close();
                providerSocket.close();
            }
            catch(IOException ioException){
                ioException.printStackTrace();
            }
        }
    }
    void sendMessage(String msg)
    {
        try{
            out.writeObject(msg);
            out.flush();
            System.out.println("server>" + msg);
        }
        catch(IOException ioException){
            ioException.printStackTrace();
        }
    }
    public static void main(String args[])
    {
        Provider server = new Provider();
        while(true){
            server.run();
        }
    }
}


//Client Side

import java.io.*;
import java.net.*;
public class Requester{
    Socket requestSocket;
    ObjectOutputStream out;
     ObjectInputStream in;
     String message;
    Requester(){}
    void run()
    {
        try{
            //1. creating a socket to connect to the server
            requestSocket = new Socket("localhost", 2004);
            System.out.println("Connected to localhost in port 2004");
            //2. get Input and Output streams
            out = new ObjectOutputStream(requestSocket.getOutputStream());
            out.flush();
            in = new ObjectInputStream(requestSocket.getInputStream());
            //3: Communicating with the server
            do{
                try{
                    message = (String)in.readObject();
                    System.out.println("server>" + message);
                    sendMessage("Hi my server");
                    sendMessage("How R U Toady");
                    message = "bye";
                    sendMessage(message);
                }
                catch(ClassNotFoundException classNot){
                    System.err.println("data received in unknown format");
                }
            }while(!message.equals("bye"));
        }
        catch(UnknownHostException unknownHost){
            System.err.println("You are trying to connect to an unknown host!");
        }
        catch(IOException ioException){
            ioException.printStackTrace();
        }
        finally{
            //4: Closing connection
            try{
                in.close();
                out.close();
                requestSocket.close();
            }
            catch(IOException ioException){
                ioException.printStackTrace();
            }
        }
    }
    void sendMessage(String msg)
    {
        try{
            out.writeObject(msg);
            out.flush();
            System.out.println("client>" + msg);
        }
        catch(IOException ioException){
            ioException.printStackTrace();
        }
    }
    public static void main(String args[])
    {
        Requester client = new Requester();
        client.run();
    }
}
 
 

Socket  Programming  Using GUI,Chat Server With Java Programming In GUI , Chat Room 

//Client Side

import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
public class ClientApp implements ActionListener,Runnable
{
  Frame f;
  Socket s;
  BufferedReader br;
  BufferedWriter bw;
  TextField text;
  Button button1,button2;
  List list;
  public static void main(String arg[])
  {
         new ClientApp();
  }
  public ClientApp()
  {
    f=new Frame("Client Application:");
    f.setSize(200,300);
    f.setLayout(new BorderLayout());
    button1=new Button("Send");
    button2=new Button("Exit");
    button1.addActionListener(this);
    button2.addActionListener(this);
    list=new List();
    text=new TextField();
    f.add(list,"Center");
    f.add(button1,"West");
    f.add(button2,"East");
    f.add(text,"South");
    f.setVisible(true);
    try
    {
       s=new Socket("localhost",100);
       br=new BufferedReader(new InputStreamReader(s.getInputStream()));
       bw=new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
       Thread th;
       th=new Thread(this);
       th.start();
    }catch (Exception e){}
  }
  public void actionPerformed(ActionEvent e)
  {
         if(e.getSource().equals(button2))
             System.exit(0);
         else
         {
           try
           {
             bw.write(text.getText());
             bw.newLine();
             bw.flush();
             text.setText("");
           }catch(Exception m){}
         }
  }
  public void run()
  {
    try
    {
       s.setSoTimeout(1);
    }catch(Exception e){}
    while(true)
    {
      try
         {
           list.addItem(br.readLine());
         }catch (Exception h){}
    }
  }
}

//Server Side

import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
public class ServerApp implements ActionListener,Runnable
{
  Frame f;
  ServerSocket s;
  Socket s1;
  BufferedReader br;
  BufferedWriter bw;
  TextField text;
  Button button1,button2;
  List list;
  public static void main(String arg[])
  {
         new ServerApp();
  }
  public ServerApp()
  {
    f=new Frame("Server Application:");
    f.setSize(200,300);
    f.setLayout(new BorderLayout());
    button1=new Button("Send");
    button2=new Button("Exit");
    button1.addActionListener(this);
    button2.addActionListener(this);
    list=new List();
    text=new TextField();
    f.add(list,"Center");
    f.add(button1,"West");
    f.add(button2,"East");
    f.add(text,"South");
    f.setVisible(true);
    try
    {
       s=new ServerSocket(100);
       s1=s.accept();
       br=new BufferedReader(new InputStreamReader(s1.getInputStream()));
       bw=new BufferedWriter(new OutputStreamWriter(s1.getOutputStream()));
       bw.write("Hello");
       bw.newLine();
       bw.flush();
       Thread th;
       th=new Thread(this);
       th.start();
    }catch (Exception e){}
  }
  public void actionPerformed(ActionEvent e)
  {
         if(e.getSource().equals(button2))
             System.exit(0);
         else
         {
           try
           {
             bw.write(text.getText());
             bw.newLine();
             bw.flush();
             text.setText("");
           }catch(Exception m){}
         }
  }
  public void run()
  {
    try
    {
       s1.setSoTimeout(1);
    }catch(Exception e){}
    while(true)
    {
      try
         {
           list.addItem(br.readLine());
         }catch (Exception h){}
    }
  }
}



Java Programming With RMI(Remote Method Invocation)

//Interface

import java.rmi.*;
interface Demo extends Remote{
    public int getSqr(int a) throws RemoteException;
}



//Server Side

import java.rmi.*;
import java.rmi.registry.*;
import java.rmi.server.*;
public class RServer extends UnicastRemoteObject implements Demo{
    public RServer() throws Exception{}
    {
        System.out.println("Server Object Created");
    }
    public static void main(String as[]){
        try{
            RServer ser=new RServer();
            Naming.rebind("myvar", ser);
        }catch(Exception e){}
    }
    public int getSqr(int a){
        return(a*a);
    }
}

//Client Side

import java.rmi.*;
import java.rmi.registry.*;
public class RClient{
    public static void main(String as[]){
        try{
            Demo d=(Demo)Naming.lookup("rmi://127.0.0.1/myvar");
            int i=d.getSqr(16);
            int j=d.getSqr(10);
            int k=d.getSqr(4);
            System.out.println("The Result is \t"+i);
System.out.println("The Result is \t"+j);
System.out.println("The Result is \t"+k);

        }catch(Exception e){}
    }
}