import *;
import *;
public class lianxi51 {
    public static void main(String[ ] args)throws UnknownHostException,IOException{
        String name=args[0];
        Socket s=new Socket(InetAddress.getLocalHost(),6666);
        DataOutputStream dos=new DataOutputStream(s.getOutputStream());
        DataInputStream dis=new DataInputStream(s.getInputStream());
        new Thread(new ReceiveMessage(dis)).start();
        new Thread(new SendMessage(dos,name)).start();
    }
}
class ReceiveMessage extends Thread{
    private DataInputStream dis;
    public ReceiveMessage(DataInputStream dis){
        this.dis=dis;
    }
    public void run(){
        try{
            System.out.println(dis.readUTF());
        }catch(IOException e){
            e.printStackTrace();
        }
    }
}
class SendMessage extends Thread{
    private DataOutputStream dos;
    private String name;
    public SendMessage(DataOutputStream dos,String name){
        this.dos=dos;
        this.name=name;
    }
    public void run(){
        String info;
        InputStreamReader is=new InputStreamReader(System.in);
        BufferedReader bf=new BufferedReader(is);
        while(true){
            try{
                info=bf.readLine();
                dos.writeUTF(name+":"+info);
            }catch (IOException e){
                e.printStackTrace();
            }
        }
    }
}

奈何没人能看出来

命令行参数没输入吧?

没看出来

Socket编程。。我没接触过。