Java学习笔记_网络(2)

单向的客户端发送服务器端接收并显示，没有使用多线程

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

 public class ChatClient {
     private JTextArea text_area;
     private PrintWriter writer;
     private Socket s;

     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();
         text_area = new JTextArea(1, 20);
         panel.add(text_area);
         JButton button = new JButton("Send");
         button.addActionListener(new SendButtonListener());
         panel.add(button);
         frame.add(BorderLayout.CENTER, panel);
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setBounds(50, 50, 400, 100);
         frame.setVisible(true);
     }

     public class SendButtonListener implements ActionListener {
         public void actionPerformed(ActionEvent a) {
             String msg = text_area.getText();
             System.out.println(msg);
             writer.println(msg);
             writer.flush(); //如果没有则服务器端收不到消息
         }
     }

     private void setup_net() {
         try {
             s = new Socket("127.0.0.1", 4242);
             writer = new PrintWriter(s.getOutputStream());
         } catch (IOException ex) {
             ex.printStackTrace();
         }
     }
 }

 import java.io.*;
 import java.net.*;

 public class ChatServer {

     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() );
                 BufferedReader reader = new BufferedReader( streamReader );
                 String msg;
                 try { //如果没有这个try则当客户端关闭后会异常退出
                     while ( (msg = reader.readLine()) != null ) {
                         System.out.println(msg);
                     }
                 } catch (IOException ex) { System.out.println("client disconnected"); }
             }
         } catch (IOException ex) {
             ex.printStackTrace();
         }
     }
 }