error: constructor Thread in class Thread cannot be applied to given types;

Hey I have this very weird bug that is probably related to my java version.

Here's my class:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;


public class ClientThread extends Thread{
    private Socket clientSocket;

    ClientThread(Socket clientSocket) {
        this.clientSocket = clientSocket;
    }

    public void run() {
        try {
            PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
            BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

            String message;
            while (((message = in.readLine()) != null)) {
                // out.println(message);
                System.out.println(message);
            }
        } catch (IOException e) {

        }
    }

    public Socket getClientSocket() {
        return clientSocket;
    }

    public void setClientSocket(final Socket clientSocket) {
        this.clientSocket = clientSocket;
    }
}

Here's my java version:

java version "1.7.0_72"
Java(TM) SE Runtime Environment (build 1.7.0_72-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.72-b04, mixed mode)

When I compile the class I get the following error:

ClientThread.java:11: error: constructor Thread in class Thread cannot be applied to given types;
    ClientThread(Socket clientSocket) {
                                      ^
  required: Socket
  found: no arguments
  reason: actual and formal argument lists differ in length
1 error

This error is very weird and I don't understand it. I found pretty much the exact same class on tutorial on the internet. I'm guessing that I have wrong version of java or something. My OS is ubuntu.