Java学习笔记_网络+多线程

支持同时收发的客户端和服务器端

客户端

 import javax.swing.*;
 import java.awt.*;
 import java.io.*;
 import java.net.*;
 import java.awt.event.*;

 public class ChatClient {
     private JTextArea incoming;
     private JTextField outgoing;
     private PrintWriter writer;
     private BufferedReader reader;

     public static void main(String[] args) {
         ChatClient client = new ChatClient();
         client.go();
     }

     private void go() {
         build_gui();
         setup_net();
     }

     private void build_gui() {
         JFrame frame = new JFrame("Chat Client");
         JPanel panel = new JPanel();

         incoming = new JTextArea(15, 50);
         incoming.setLineWrap(true);
         incoming.setWrapStyleWord(true);
         incoming.setEditable(false);
         JScrollPane qScroller = new JScrollPane(incoming);
         qScroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
         qScroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
         panel.add(incoming);

         outgoing = new JTextField(20);
         panel.add(outgoing);

         JButton button = new JButton("Send");
         button.addActionListener(new SendButtonListener());
         panel.add(button);

         frame.add(BorderLayout.CENTER, panel);
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setSize(600, 400);
         frame.setVisible(true);
     }

     public class SendButtonListener implements ActionListener {
         public void actionPerformed(ActionEvent a) {
             String msg = outgoing.getText();
             try {
                 writer.println(msg);
                 writer.flush();
             } catch (Exception ex) { ex.printStackTrace(); }
             outgoing.setText("");
             outgoing.requestFocus();
         }
     }

     class ReceiveThreadJob implements Runnable {
         public void run() {
             String msg;
             try {
                 while ( (msg = reader.readLine()) != null ) {
                     incoming.append(msg + "\n");
                 }
             } catch (IOException ex) { System.out.println("server disconnected"); }
         }
     }

     private void setup_net() {
         try {
             Socket s = new Socket("127.0.0.1", 4242);
             writer = new PrintWriter(s.getOutputStream());
             InputStreamReader streamReader = new InputStreamReader( s.getInputStream() );
             reader = new BufferedReader( streamReader );    

             Runnable receive_thread_job = new ReceiveThreadJob();
             Thread receive_thread = new Thread( receive_thread_job );
             receive_thread.start();

         } catch (IOException ex) {
             ex.printStackTrace();
         }
     }
 }

服务器端

 import java.io.*;
 import java.net.*;
 import java.util.ArrayList;

 public class ChatServer {
     BufferedReader reader;
     ArrayList<PrintWriter> writer_array = new ArrayList<PrintWriter>();

     public static void main(String[] args) {
         ChatServer server = new ChatServer();
         server.go();
     }

     private void go() {
         setup_net();
     }

     private void setup_net() {
         try {
             ServerSocket serverSock = new ServerSocket(4242);
             while (true) {
                 Socket s = serverSock.accept();
                 System.out.println("client connected");
                 InputStreamReader streamReader = new InputStreamReader( s.getInputStream() );
                 reader = new BufferedReader( streamReader );
                 PrintWriter writer = new PrintWriter(s.getOutputStream());
                 writer_array.add(writer);
                 Runnable server_proc_thread_job = new ServerProcThreadJob();
                 Thread server_proc = new Thread( server_proc_thread_job );
                 server_proc.start();
             }
         } catch (IOException ex) {
             ex.printStackTrace();
         }
     }

     class ServerProcThreadJob implements Runnable {
         public void run() {
             String msg;
             try {
                 while ( (msg = reader.readLine()) != null ) {
                     System.out.println(msg);
                     for ( PrintWriter writer: writer_array ) {
                         writer.println(msg);
                         writer.flush();
                     }
                 }
             } catch (IOException ex) { System.out.println("client disconnected"); }
         }
     }
 }