Please Sign up or sign in to vote.

Actual Client Desktop

Remote Image of the Connected Client Desktop

Introduction

This program allows any computer to control other PCs remotely.

Program Features

View remote desktop

Mouse movement control

Mouse buttons control

Keyboard control

Background

One of the biggest challenges in this project is finding a way to move the mouse pointer, simulate key stroke and capture the screen. After spending some time I found a great class, Robot class that does all that I need.

In addition, using serialization to send screenshots from client to server and to send server events like mouse move, key press, key release helped me a lot to write clean and simple code instead of sending images and events in raw data format over the network.

Robot Class Methods

mouseMove - Moves the mouse pointer to a set of specified absolute screen coordinates given in pixels

- Moves the mouse pointer to a set of specified absolute screen coordinates given in pixels mousePress - Presses one of the buttons on the mouse

- Presses one of the buttons on the mouse mouseRelease - Releases one of the buttons on the mouse

- Releases one of the buttons on the mouse keyPress - Presses a specified key on the keyboard

- Presses a specified key on the keyboard keyRelease - Releases specified key on the keyboard

- Releases specified key on the keyboard createScreenCapture - Takes a screenshot

Program Parts

1. RemoteServer

This is the server part which waits for clients connections and per each connected client, a new frame appears showing the current client screen. When you move the mouse over the frame, this results in moving the mouse at the client side. The same happens when you right/left click mouse button or type a key while the frame is in focus.

2. RemoteClient

This the client side, its core function is sending a screen shot of the client's desktop every predefined amount of time. Also it receives server commands such as "move the mouse command", then executes the command at the client's PC.

Using the Code

In order to run the program, you need to download RemoteServer_source.zip and RemoteClient_source.zip on two different PCs, then extract them. In one of the PCs say PC1, run RemoteServer.jar which is located under dist folder using the following command:

>> java -jar RemoteServer.jar

You will be asked to enter port number for the server to listen at, enter any port number above 1024, for example 5000.

On the other PC say PC2, execute RemoteClient.jar using the following command:

>> java -jar RemoteClient.jar

You will be asked to enter server IP, enter IP address of PC1, then you will be asked to enter port number, enter the same port you entered above, e.g. 5000.

Now, in PC1 you have full control over PC2 including moving the mouse, clicking the mouse, keys stroking, viewing PC2 desktop, etc.

Coding Structure

RemoteServer

ServerInitiator Class

This is the entry class which listens to server port and wait for clients connections. Also, it creates an essential part of the program GUI.

ClientHandler Class

Per each connected client, there is an object of this class. It shows an InternalFrame per client and it receives clients' screen dimension.

ClientScreenReciever Class

Receives captured screen from the client, then displays it.

ClientCommandsSender Class

It listens to the server commands, then sends them to the client. Server commands include mouse move, key stroke, mouse click, etc.

EnumCommands Class

Defines constants which are used to represent server commands.

RemoteClient

ClientInitiator Class

This is the entry class that starts the client instance. It establishes connection to the server and creates the client GUI.

ScreenSpyer Class

Captures screen periodically and sends them to the server.

ServerDelegate Class

Receives server commands and executes them in the client PC.

EnumCommands Class

Defines constants which are used to represent server commands.

Code Snippets

1) RemoteClient

Connect to Server

System.out.println( " Connecting to server .........." ); socket = new Socket(ip, port); System.out.println( " Connection Established." );

Capture Desktop Screen then Send it to the Server Periodically

In ScreenSpyer class, Screen is captured using createScreenCapture method in Robot class and it accepts a Rectangle object which carries screen dimension. If we try to send image object directly using serialization, it will fail because it does not implement Serializable interface. That is why we have to wrap it using the ImageIcon class as shown below:

while (continueLoop){ BufferedImage image = robot.createScreenCapture(rectangle); ImageIcon imageIcon = new ImageIcon(image); try { System.out.println( " before sending image" ); oos.writeObject(imageIcon); oos.reset(); System.out.println( " New screenshot sent" ); } catch (IOException ex) { ex.printStackTrace(); } try { Thread.sleep( 100 ); } catch (InterruptedException e){ e.printStackTrace(); } }

Receive Server Events then call Robot Class Methods to Execute these Events

while (continueLoop){ System.out.println( " Waiting for command" ); int command = scanner.nextInt(); System.out.println( " New command: " + command); switch (command){ case - 1 : robot.mousePress(scanner.nextInt()); break ; case - 2 : robot.mouseRelease(scanner.nextInt()); break ; case - 3 : robot.keyPress(scanner.nextInt()); break ; case - 4 : robot.keyRelease(scanner.nextInt()); break ; case - 5 : robot.mouseMove(scanner.nextInt(), scanner.nextInt()); break ; } }

2) RemoteServer

Wait for Clients Connections

while (true){ Socket client = sc.accept(); System.out.println( " New client Connected to the server" ); new ClientHandler(client,desktop); }

Receive Client Desktop Screenshots and Display them

while (continueLoop){ ImageIcon imageIcon = (ImageIcon) cObjectInputStream.readObject(); System.out.println( " New image received" ); Image image = imageIcon.getImage(); image = image.getScaledInstance (cPanel.getWidth(),cPanel.getHeight(),Image.SCALE_FAST); Graphics graphics = cPanel.getGraphics(); graphics.drawImage(image, 0 , 0 , cPanel.getWidth(),cPanel.getHeight(),cPanel); }

Handle Mouse and Key Events then Send them to the Client Program to Simulate them

In ClientCommandsSender class, when mouse is moved, x and y values are sent to the client but we have to take into consideration the size difference between clients' screen size and server's panel size, that is why we have to multiply by a certain factor as shown in the following code: