// Client.java

/*
 * In this client/server example, the client sends a file to the server.
 *
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;

public class Client extends JFrame implements ActionListener {

    private JTextField txtFile;
   
    public static void main(String args[]){

        /* Create and display the client form */

        Client clientForm = new Client();
        clientForm.Display();
    }

    public void Display(){

        JFrame frame = new JFrame();
        frame.setTitle("Client");

        FlowLayout layout = new FlowLayout();
        layout.setAlignment(FlowLayout.LEFT);

        JLabel lblFile = new JLabel("Filename:");
       
        txtFile = new JTextField();
        txtFile.setPreferredSize(new Dimension(150,30));

        JButton btnTransfer = new JButton("Transfer");
        btnTransfer.addActionListener(this);

        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(layout);
        mainPanel.add(lblFile);
        mainPanel.add(txtFile);
        mainPanel.add(btnTransfer);

        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {

        /* File Open Dialog box allows the user to select a file */

        JFileChooser fileDlg = new JFileChooser();
        fileDlg.showOpenDialog(this);
        String filename = fileDlg.getSelectedFile().getAbsolutePath();
        txtFile.setText(filename);

        try{

            /* Try to connect to the server on localhost, port 5555 */

            Socket sk = new Socket("localhost", 5555);
            OutputStream output = sk.getOutputStream();

            /* Send filename to server */

            OutputStreamWriter outputStream = new OutputStreamWriter(sk.getOutputStream());
            outputStream.write(fileDlg.getSelectedFile().getName() + "\n");
            outputStream.flush();

            /* Get reponse from server */

            BufferedReader inReader = new BufferedReader(new InputStreamReader(sk.getInputStream()));

            String serverStatus = inReader.readLine(); // Read the first line

            /* If server is ready, send the file */

            if ( serverStatus.equals("READY") ){

                FileInputStream file = new FileInputStream(filename);

                byte[] buffer = new byte[sk.getSendBufferSize()];

                int bytesRead = 0;

                while((bytesRead = file.read(buffer))>0)
                {
                    output.write(buffer,0,bytesRead);
                }

                output.close();
                file.close();
                sk.close();

                JOptionPane.showMessageDialog(this, "Transfer complete");
            }
        }
        catch (Exception ex){
            /* Catch any errors */
            JOptionPane.showMessageDialog(this, ex.getMessage());
        }
    }
}


// Server.java

/*
 * Server waits for a connection to be established by client
 *
 */

import java.io.*;
import java.net.*;

class Server
{
    public static void main(String args[])throws Exception
    {
        System.out.println("Server running...");

        /* Listen on port 5555 */

        ServerSocket server = new ServerSocket(5555);

        /* Accept the sk */

        Socket sk = server.accept();
       
        System.out.println("Server accepted client");
        InputStream input = sk.getInputStream();
        BufferedReader inReader = new BufferedReader(new InputStreamReader(sk.getInputStream()));
        BufferedWriter outReader = new BufferedWriter(new OutputStreamWriter(sk.getOutputStream()));

        /* Read the filename */
        String filename = inReader.readLine();

        if ( !filename.equals("") ){

            /* Reply back to client with READY status */

            outReader.write("READY\n");
            outReader.flush();
        }

        /* Create a new file in the tmp directory using the filename */
        FileOutputStream wr = new FileOutputStream(new File("C://tmp/" + filename));

        byte[] buffer = new byte[sk.getReceiveBufferSize()];

        int bytesReceived = 0;

        while((bytesReceived = input.read(buffer))>0)
        {
            /* Write to the file */
           wr.write(buffer,0,bytesReceived);
        }
    }
}