如何关闭正在运行的套接字线程？

我正在运行一个启用多个套接字连接的服务器。我正在尝试在客户端终止连接时关闭线程。

这是客户端线程的代码：

class ClientThread implements Runnable {
    Socket threadSocket;
    private boolean chk = false, stop = false, sendchk = false, running = true;
    DataOutputStream out = null;

    //This constructor will be passed the socket
    public ClientThread(Socket socket){
        threadSocket = socket;
    }

    public void run()
    {
        System.out.println("New connection at " + new Date() + "\n");
        try {
            DataInputStream in = new DataInputStream (threadSocket.getInputStream());
            out = new DataOutputStream (threadSocket.getOutputStream());                  
            while (running){
                // read input from client
                int ln = in.available();
                byte [] bytes  = new byte [ln];
                in.read(bytes);
                String msg = new String(bytes);

                // parse in going message
                messageParsing(msg);

                // respond to client
                response();

                /////////////////////////////
                ////// this is the part that i thought would help me close the thread
                ////////////////////////////
                if (threadSocket.isInputShutdown()){
                    running = false;
                }
            }
        } 
        catch (IOException ex) {System.out.println(ex);}
        finally {
            try {
                threadSocket.close();
                System.out.println("Connection closed due to unauthorized entry.\n");
            } catch (IOException ex) {System.out.println(ex);}
        }
    }}

但是，该if语句不能解决问题。该线程仍在运行，并尝试从套接字发送/读取数据。如何使其工作？我想念什么？任何帮助，将不胜感激。谢谢你。