GUI Online.

Client.java

import java.net.*;
import java.io.*;
public class Client {
    public static void main(String[] args) throws IOException {
		while(true)
		{
			String sentence;
			String modifiedSentence;
			BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));
			Socket clientSocket = new Socket("localhost", 6789);
			DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
			BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
			sentence = inFromUser.readLine();
			outToServer.writeBytes(sentence + '\n');
			modifiedSentence = inFromServer.readLine();
			System.out.println("FROM SERVER: " + modifiedSentence);
			clientSocket.close();
		}
    }
}

JFrameClickEventExample.java

import java.io.*;
import java.text.*;
import java.lang.*;
import java.util.*;

import java.util.Timer;
import java.util.TimerTask;

import javax.swing.*;
import javax.swing.ImageIcon;
import javax.imageio.*;

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;

public class JFrameClickEventExample 
	extends JFrame 
	implements MouseListener, MouseMotionListener, KeyListener 
{
	public static BufferedImage scrnsht;
	public static ArrayList<String> drawlog = new ArrayList<String>();
	public BufferedImage ScreenShot() {
			try {
				GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
				GraphicsDevice[] screens = ge.getScreenDevices();
				
				Rectangle allScreenBounds = new Rectangle();
				for (GraphicsDevice screen : screens) {
				    Rectangle screenBounds = screen.getDefaultConfiguration().getBounds();
				
				    allScreenBounds.width += screenBounds.width;
				    allScreenBounds.height = Math.max(allScreenBounds.height, screenBounds.height);
				}
				
				Robot robot = new Robot();
				return robot.createScreenCapture(allScreenBounds);
				
			}catch(Exception ex){
				BufferedImage bi = new BufferedImage(800, 600, BufferedImage.TYPE_INT_RGB);
				Graphics g = bi.getGraphics();
				g.setColor(Color.red);
				g.fillRect(300, 350, 100, 50);
				return bi;
			}
		}
	public class DrawPanel extends JPanel {
		@Override 
		public void paintComponent(Graphics g) {
			g.drawImage(scrnsht,0,0,this);
			for (int i = drawlog.size();i-->0;){
				g.drawString(drawlog.get(i),10,(i+1)*32);
			}
			/*Timer timer = new Timer("MyTimer");
			timer.schedule(new TimerTask() {
				@Override
				public void run() {
					again();
					System.out.println("hello");
				}
			}, 1000);*/
			
		}
	}
	public JLabel label;
	public static void main(String args[]) 
	{
		new JFrameClickEventExample();
	}
	JFrameClickEventExample() 
	{
		setSize(500, 400);
		setTitle("Java Swing - JFrame  Detect Mouse Events");

		label = new JLabel("No Mouse Event Captured", JLabel.CENTER);
		add(label);
		addMouseListener(this);
		addMouseMotionListener(this);
		addKeyListener(this);
		setVisible(true);
		setAlwaysOnTop(true);
		DrawPanel panel = new DrawPanel();                            // window for drawing
		
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   // set frame to exit
		                                                  // when it is closed
		add(panel);
	}
	public void mousePressed(MouseEvent evt) { 
		
	}
	public void mouseDragged(MouseEvent evt) {
		System.out.println("Derp"); 
	}
	public void mouseReleased(MouseEvent evt) { }
	public void mouseClicked(MouseEvent evt) { }  // Other methods in the MouseListener interface
	public void mouseEntered(MouseEvent evt) { }
	public void mouseExited(MouseEvent evt) { }
	public void mouseMoved(MouseEvent evt) { /*label.setText("Moving"); */}  // Required by the MouseMotionListener interface.
	String input = "";
	public void keyTyped(KeyEvent e) { 
	}
    public void keyPressed(KeyEvent e) {
		if(e.getKeyCode()==KeyEvent.VK_ENTER){
    		drawlog.add(input);
    		input = "";
		}else if(e.getKeyCode()==KeyEvent.VK_BACK_SPACE&&input.length()>0){
    		input = input.substring(0,input.length()-1);
		}else if(e.getKeyCode()==KeyEvent.VK_SHIFT){
			scrnsht=ScreenShot();
		}else if(e.getKeyChar()==KeyEvent.VK_PRINTSCREEN){
			scrnsht=ScreenShot();
		}else{
			input += e.getKeyChar();
		}
        label.setText(input);
    }
    public void keyReleased(KeyEvent e) { }
}

Server.java

import java.net.*;
import java.io.*;
public class Server {
    public static void main(String[] args) throws IOException {
		String clientSentence;
		String capitalizedSentence;
		ServerSocket welcomeSocket = new ServerSocket(6789);
		while(true)
		{
			Socket connectionSocket = welcomeSocket.accept();
			BufferedReader inFromClient =
			new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
			DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());
			clientSentence = inFromClient.readLine();
			System.out.println("Received: " + clientSentence);
			capitalizedSentence = clientSentence.toUpperCase() + '\n';
			outToClient.writeBytes(capitalizedSentence);
		}
    }
}