package com.swift;import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.net.BindException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.List;public class ChatServer {boolean started = false;ServerSocket ss = null;Socket s = null;List<Client> clients=new ArrayList<Client>();  public static void main(String[] args) {new ChatServer().fun();}private void fun() {try {ss = new ServerSocket(8888);started = true;} catch (BindException e) {System.out.println("端口使用中......");} catch (IOException e1) {e1.printStackTrace();}try {while (started) {s = ss.accept();System.out.println("a client connected success");Client c = new Client(s);new Thread(c).start();clients.add(c);}} catch (EOFException e) {System.out.println("client has closed.");} catch (Exception e) {e.printStackTrace();} finally {try {ss.close();} catch (IOException e) {// TODO Auto-generated catch block
                e.printStackTrace();}}}class Client implements Runnable {private Socket s;private DataInputStream dis;private DataOutputStream dos;private boolean connected = false;public Client(Socket s) {this.s = s;try {this.dis = new DataInputStream(s.getInputStream());this.dos = new DataOutputStream(s.getOutputStream());connected = true;} catch (IOException e) {// TODO Auto-generated catch block
                e.printStackTrace();}}private void send(String str) {try {dos.writeUTF(str);} catch(SocketException e) {clients.remove(this);} catch (IOException e) {e.printStackTrace();};}@Overridepublic void run() {try {//注意:要包括while循环，如果try在while循环里，则出现socket closed异常while (connected) {String str = dis.readUTF();System.out.println(str);for(int i=0;i<clients.size();i++) {Client c=clients.get(i);c.send(str);}//                     for(Iterator<Client> it=clients.iterator();it.hasNext();) {
//                         Client c=it.next();//方法二，不可取，有同步锁
//                         c.send(str);
//                     }//                    Iterator<Client> it=clients.iterator();
//                    while(it.hasNext()) {
//                        Client c=it.next();//方法三，不可取，有同步锁,修改需要加锁（此时没修改）
//                        c.send(str);
//                    }
                     }} catch(EOFException e) {System.out.println("a client has been closed,can't read message from it.");} catch (IOException e) {e.printStackTrace();} finally {if (dis != null) {try {dis.close();} catch (IOException e) {e.printStackTrace();}}if(dos!=null) {try {dos.close();} catch (IOException e) {e.printStackTrace();}}if (s != null) {try {s.close();} catch (IOException e) {e.printStackTrace();}}}}}
}

package com.swift;import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ConnectException;
import java.net.Socket;
import java.net.SocketException;import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;public class ChatClientFrame extends JFrame {private static final long serialVersionUID = -118470059355655240L;Socket s;DataOutputStream dos;DataInputStream dis;private boolean connected = false;JLabel label_shang = new JLabel();JLabel label_xia = new JLabel();JTextField tf = new JTextField(38);JTextArea ta = new JTextArea(15, 50);JButton button = new JButton();public ChatClientFrame() {setBounds(200, 200, 500, 400);setTitle("客户端聊天工具 —— 1.0");// 对窗口进行大的布局，分为三行一列，在pBasic面板上添加三个面板shang zhong xiaJPanel pBasic = new JPanel();pBasic.setLayout(new BorderLayout());// 不设置默认也是这种布局模式setContentPane(pBasic);// 把面板放在窗口上，不记得用this.关键字JPanel shang = new JPanel();JPanel zhong = new JPanel();JPanel xia = new JPanel();// 设置JPanel面板的大小shang.setSize(470, 25);zhong.setSize(470, 180);xia.setSize(470, 40);pBasic.add(shang, BorderLayout.NORTH);pBasic.add(zhong, BorderLayout.CENTER);pBasic.add(xia, BorderLayout.SOUTH);shang.setBackground(Color.red);zhong.setBackground(Color.yellow);xia.setBackground(Color.blue);label_shang.setText("聊天记录");shang.add(label_shang);ta.setLineWrap(true);// 自动换行JScrollPane scroll = new JScrollPane(ta);// 增加滚动条，以便不增加行数
        zhong.add(scroll);label_xia.setText("输入信息");xia.add(label_xia, BorderLayout.WEST);/** 增加功能，窗口监听事件，窗口打开时设置光标焦点在tf文本域中*/this.addWindowListener(new WindowAdapter() {@Overridepublic void windowOpened(WindowEvent e) {tf.requestFocus();}});xia.add(tf, BorderLayout.CENTER);button.setText("发送");xia.add(button, BorderLayout.EAST);button.addActionListener(new ShareListener());tf.addActionListener(new ShareListener());pack();this.addWindowListener(new WindowAdapter() {@Overridepublic void windowClosing(WindowEvent e) {disconnect();System.exit(0);}});setVisible(true);// 创建窗体直接调用连接服务器
        connect();Thread t=new Thread(new ReceiveThread());t.start();}class ShareListener implements ActionListener {@Overridepublic void actionPerformed(ActionEvent e) {String tfText1 = tf.getText();tf.setText("");// 当回车或发送按钮时，tfText发送到服务器try {dos.writeUTF(tfText1);dos.flush();} catch (IOException e1) {e1.printStackTrace();}}}class ReceiveThread implements Runnable {@Overridepublic void run() {try {while (connected) {String str = dis.readUTF();System.out.println(str);ta.setText(ta.getText()+str+"\r\n");}} catch (SocketException e) {System.out.println("a client has been closed!");} catch (IOException e) {e.printStackTrace();}}}public void connect() {try {s = new Socket("127.0.0.1", 8888);System.out.println("connected!");connected=true;dos = new DataOutputStream(s.getOutputStream());dis = new DataInputStream(s.getInputStream());} catch (ConnectException e) {System.out.println("服务端异常.........");System.out.println("请确认服务端是否开启.........");} catch (IOException e) {e.printStackTrace();}}public void disconnect() {try {if (dos != null)dos.close();if(dis !=null)dis.close();if (s != null)s.close();} catch (IOException e) {e.printStackTrace();}}public static void main(String[] args) {new ChatClientFrame();}}