关于 JAVA的控制台聊天程序

现在遇到了困难：我是用JAVA编写的。因为程序获取用户输入数据这个函数是阻塞函数，所以，程序不得不等待用户的输入后，才能执行下一步，这就导致了就算服务端发送了数据，也不能接受！！另外，接受服务端的数据的函数也是个阻塞函数，同样有这样的问题！
我现在想要实现这样的效果：用户的输入和接受数据不受到阻塞函数的影响！可以方便的发送和接收！
根据问题我写的代码：
服务端：

package chen.chat;
import java.io.*;
import java.net.*;
public class Server
{
    public static void main(String [] agrs)
    {
        try
        {
            ServerSocket server=new ServerSocket(4000);
            System.out.println("服务器开启");
            while(true)
            {
                Socket client=server.accept();
                try
                {
                    System.out.println("客户已经连接到服务器");
                    System.out.println("IP:"+client.getInetAddress().getHostAddress()+"Port: "+client.getPort());
                    new ServerThread(client).start();
                }
                catch(Exception e)
                {
                    e.printStackTrace();
                }
            }
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
    }
}
class ServerThread extends Thread
{
    private Socket client ;
    private BufferedReader bfSystemInput;
    private BufferedReader bfSocketInput;
    private PrintWriter outer;
    public ServerThread(Socket socket)
    {
        try
        {
            this.client=socket;
            this.bfSystemInput=new BufferedReader(new InputStreamReader(System.in));
            this.bfSocketInput=new BufferedReader(new InputStreamReader(this.client.getInputStream()));
            this.outer=new PrintWriter(this.client.getOutputStream());
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
    }
    public void run()
    {
        ListernerSystem lstSocket=new ListernerSystem(this.bfSocketInput);
        ListenerSystem lstSystem=new ListenerSystem(this.bfSystemInput,this.outer);
        lstSocket.start();
        lstSystem.start();
    }
}
class ListernerSystem extends Thread
{
    private BufferedReader bfSocketInput;
    public ListernerSystem(BufferedReader bf)
    {
        this.bfSocketInput=bf;
    }
    public void run()
    {
        while(true)
        {
            String msg=null;
            try
            {
                if((msg=bfSocketInput.readLine())!=null)
                {
                    System.out.println("Your friend say: "+msg);
                    
                }
                else
                {
                    System.out.println("dsa");
                }
            }
            catch(IOException e)
            {
                e.printStackTrace();
            }
        }
    }
}
class ListenerSystem extends Thread
{
    private BufferedReader bfSystemInput;
    private PrintWriter outer;
    public ListenerSystem(BufferedReader bf,PrintWriter out)
    {
        this.bfSystemInput=bf;
        this.outer=out;
    }
    public void run()
    {
        while(true)
        {
            try
            {
                String msg=null;
                if((msg=bfSystemInput.readLine())!=null)
                {
                    this.outer.println("You Say: "+msg);
                }
                else
                {
                    System.out.println("dsa");
                }
            }
            catch(IOException e)
            {
                e.printStackTrace();
            }
        }
    }
}

客户端：

package chen.chat;
import java.io.*;
import java.net.*;
public class Client
{
    public static void main(String [] agrs)
    {
        try
        {
            Socket client=new Socket("127.0.0.1",4000);
            System.out.println("连接服务器成功");
            BufferedReader bfSystemInput=new BufferedReader(new InputStreamReader(System.in));
            BufferedReader bfSocketInput=new BufferedReader(new InputStreamReader(client.getInputStream()));
            PrintWriter out=new PrintWriter(client.getOutputStream());
            new ListenSocket(bfSocketInput).start();
            new ListenControlInput(bfSystemInput,out).start();
        }
        catch(UnknownHostException e)
        {
            e.printStackTrace();
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
    }
}
class ListenSocket extends Thread
{
    private BufferedReader bfSocketInput;
    public ListenSocket(BufferedReader bf)
    {
        this.bfSocketInput=bf;
    }
    public void run()
    {
        while(true)
        {
            String msg=null;
            try
            {
                if((msg=bfSocketInput.readLine())!=null)
                {
                    System.out.println("Your friend say: "+msg);
                }
            }
            catch(IOException e)
            {
                e.printStackTrace();
            }
        }
    }
}
class ListenControlInput extends Thread
{
    private BufferedReader bfSystemInput;
    private PrintWriter out;
    public ListenControlInput(BufferedReader bf,PrintWriter out)
    {
        this.bfSystemInput=bf;
        this.out=out;
    }
    public void run()
    {
        String msg=null;
        while(true)
        {
            try
            {
                msg=this.bfSystemInput.readLine();
                if(msg!=null)
                    this.out.println("You Say: "+msg);
            }
            catch(IOException e)
            {
                e.printStackTrace();
            }
        }
    }
}

执行后，客户端或者服务端并不会接收到数据。
我将发送数据和接收数据 分开写入一个线程里面了。
大虾帮忙看下。。。小弟忙活2天了。。。