关于Socket的问题：

Question

1 服务端不一定是java的server socket，可以用c, vb, delphi等做出serversocket
2 new Socket("127.0.0.1,1800"); >>> new Socket("127.0.0.1", 1800);
3 不是的，比如你可以连 www.163.com 的80端口，你能读到一个网易的首页

Answer 1

// ServerSocketSample.javaimport java.io.*;
import java.net.*;
import javax.swing.*;
import javax.swing.JFrame;
import java.awt.event.*;
import java.awt.*;public class ServerSocketSample extends JFrame implements ActionListener,Runnable
{
    public final int port = 23711;
    private ServerSocket serversocket = null;
    private JTextArea txt = null;
    private static ServerSocketSample serverSocketSample1 = null;
    private JButton btn_accept = null;
    private JButton btn_stop = null;
    private boolean socket_closed = true;
    public ServerSocketSample()
    {
        super();
        addWindowListener
        (
        new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        }
        );        JPanel jp = new JPanel();
        btn_accept = new JButton("Accept");
        btn_accept.addActionListener(this);
        jp.add(btn_accept);
        btn_stop = new JButton("Stop");
        btn_stop.addActionListener(this);
        btn_stop.setEnabled(false);
        jp.add(btn_stop);
        getContentPane().add(jp,BorderLayout.NORTH);
        txt = new JTextArea();
        txt.setEditable(false);
        txt.setLineWrap(true);
        JScrollPane jsp = new JScrollPane(txt);        getContentPane().add(jsp);
        txt.setTabSize(4);
        setSize(400,400);
        setVisible(true);
    }    public void run()
    {
        try
        {
            while(!socket_closed)
            {
                Socket ClientSocket = serversocket.accept();
                BufferedReader reader = new BufferedReader(new InputStreamReader(ClientSocket.getInputStream()));
                String msg = reader.readLine();
                txt.append(msg);
                PrintWriter output = new PrintWriter(ClientSocket.getOutputStream(),true);
                output.println("服务器：" + msg + "\n\r");
                reader.close();
                output.close();
                ClientSocket.close();
            }
        }
        catch(IOException ex)
        {ex.printStackTrace();}
    }    public void actionPerformed(ActionEvent e)
    {
        Thread LocalThread = new Thread(serverSocketSample1,"ServerSocketSample");
        if(e.getActionCommand() == "Accept")
        {
            try { serversocket = new ServerSocket(port); }
            catch(IOException ex) { ex.printStackTrace(); }            socket_closed = false;
            LocalThread.start();
            txt.append("开始监听……\n");
            btn_accept.setEnabled(false);
            btn_stop.setEnabled(true);
        }
        else
        {
            socket_closed = true;
            try { serversocket.close(); }
            catch(IOException ex) { ex.printStackTrace(); }            txt.append("停止监听……\n");            btn_accept.setEnabled(true);
            btn_stop.setEnabled(false);
        }
    }    public static void main(String[] args)
    {
        serverSocketSample1 = new ServerSocketSample();
    }}

Answer 2

// ClientSocketSample.javaimport java.net.*;
import java.io.*;public class ClientSocketSample
{
    public static final String host = "192.168.1.219";
    public static final int port = 23711;
    public ClientSocketSample()
    {
        super();
    }    public void testEcho()
    {
        try
        {
            Socket clientS = new Socket(host,port);
            PrintWriter output = new PrintWriter(clientS.getOutputStream(),true);
            BufferedReader reader = new BufferedReader(new InputStreamReader(clientS.getInputStream()));
     //       output.write("Hello");
            output.println("Hello");
            System.out.println("Server:" + reader.readLine());
            output.close();
            reader.close();
            clientS.close();
        }
        catch(UnknownHostException ex)
        {
            ex.printStackTrace();
        }
        catch(IOException ex)
        {
            ex.printStackTrace();
        }
    }    public static void main(String[] args)
    {
        ClientSocketSample clientSocketSample1 = new ClientSocketSample();
        clientSocketSample1.testEcho();
    }
}