framechatclient.java

《Java程序设计与应用》-张仕斌-源程序 《Java程序设计与应用》-张仕斌-源程序

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

public class FrameChatClient extends JFrame implements Runnable,ActionListener{
	private JTextField txtServer = null;  //服务器名
	private JTextField txtPort = null;    //服务器端口
	private JTextField txtUser = null;    //登录用户名
	private JTextField txtChat = null;    //当前发送信息
	private JButton btnConnect = null;    //连接按钮
	private JButton btnSend = null;       //发送消息按钮
	private JButton btnClose = null;      //断开连接按钮
	private JTextArea ta = null;          //聊天内容
	private Socket client = null;         //套接字
	private BufferedReader in = null;
	private DataOutputStream out = null;
	private Thread curThread = null;      //当前线程
	
	public FrameChatClient() {
		super("Java聊天程序");
		
		txtServer = new JTextField(10);
		txtPort = new JTextField(6);
		txtUser = new JTextField(5);
		txtChat = new JTextField(38);
		
		btnConnect = new JButton("连接");
		btnSend = new JButton("发送");
		btnClose = new JButton("关闭");
		
		Container cp = this.getContentPane();
		Panel p = new Panel();
		p.setLayout(new FlowLayout(FlowLayout.LEFT));
		p.add(new JLabel("服务器:"));
		p.add(txtServer);
		p.add(new JLabel("端口:"));
		p.add(txtPort);
		p.add(new JLabel("用户名:"));
		p.add(txtUser);
		p.add(btnConnect);
		p.add(btnClose);
		cp.add(p , BorderLayout.NORTH);
		
		p = new Panel();
		p.setLayout(new FlowLayout(FlowLayout.LEFT));
		p.add(new JLabel("发言:"));
		p.add(txtChat);
		p.add(btnSend);
		cp.add(p , BorderLayout.SOUTH);
		
		ta = new JTextArea(6 , 35);
		JScrollPane sp = new JScrollPane(ta);
		cp.add(sp , BorderLayout.CENTER);
		
		btnConnect.addActionListener(this);  //连接
		btnClose.addActionListener(this);		//断开
		btnSend.addActionListener(this);   //发送
	}
	
	public void actionPerformed(ActionEvent e) {  //处理按钮
		if (e.getSource() == btnConnect) {         //如果是连接
				String strServer , strPort , strUser ;
				strServer = txtServer.getText().trim();
				strPort = txtPort.getText().trim();
				strUser = txtUser.getText().trim();   
				/*要求服务器,端口,用户名都不能为空*/
				if (strServer.equals("") || strPort.equals("") || strUser.equals("")) {
					return;
				}
				if (client != null ){    //如果已经连接
					JOptionPane.showMessageDialog(this , "请先断开连接!" ,
			                     "连接错误" , JOptionPane.PLAIN_MESSAGE);
			    return;
			  }
				try {           //建立连接
					client = new Socket(strServer , Integer.parseInt(strPort)); //创建套接字
					in = new BufferedReader(new InputStreamReader(client.getInputStream()));
					out = new DataOutputStream(client.getOutputStream());
					out.writeBytes(strUser + "\n");  //先发送用户名
					curThread = new Thread(this);    //创建服务线程
					curThread.start();               //启动线程
				}catch(Exception ce) {
					JOptionPane.showMessageDialog(this , "请检查服务器和端口设置!" ,
			                     "连接错误" , JOptionPane.PLAIN_MESSAGE);
				}
		}
		
		if (e.getSource() == btnClose) {    //如果是断开,则调用close()
			close();
		}
		
		if (e.getSource() == btnSend) {     //如果是发送信息
				String strChat = txtChat.getText().trim();
				txtChat.setText("");
				if (strChat.equals("")) {    //忽略空消息
					return;
				}
				if (strChat.equals("Quit")) {  //如果是退出
					close();
				}else {
					sendMsg(strChat);     //发送消息
				}
		}
	}
	
	public void close() {   //断开连接
		curThread = null;     //停止线程
		if (client != null) {	
			try {
				sendMsg("Quit");	  //发送结束标志
				in.close();
				out.close();
				client.close();
			}catch(Exception xe) {
				xe.printStackTrace();
			}				
			client = null;
		}else {
			JOptionPane.showMessageDialog(this , "未连接到服务器!" ,
		                    "错误" , JOptionPane.PLAIN_MESSAGE);
		}
	}
	
	public void sendMsg(String msg) {  //发送消息
		if (out != null && client != null) {
			try {
				out.writeBytes(msg + "\n");
			}catch(IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	public void run() {   //主线程
		Thread t = Thread.currentThread();
		while (t == curThread && client != null) {
			try {
				String str = in.readLine();  //读取服务器发送的信息
				ta.append(str + "\n");
			}catch(IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	public static void main(String[]args) {
		FrameChatClient fcc = new FrameChatClient();
		fcc.setSize(540,300);
		fcc.setDefaultCloseOperation(EXIT_ON_CLOSE);
		fcc.setVisible(true);
		fcc.setResizable(false);
	}
}