多线程服务器程序

古城微笑少年丶 2022-05-30 03:50 242阅读 0赞

为了同时对多个客户机进行服务，需要利用多线程。下面的程序样例，服务器与多个客户机进行交谈。对于每个客户服务，都使用一个线程（这里类名为Connection）,线程的任务是接受客户机的字符并显示出来。

**服务器程序：**

import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    import java.io.*;
    import java.net.*;
    import java.util.Vector;
    
    public class ChatServer extends JFrame implements Runnable{
    	JPanel contentPane;
    	JTextField txtInput = new JTextField();
    	JButton btnSend = new JButton();
    	List lstMsg = new List();
    	
    	/**Construct the frame*/
    	public ChatServer() {
    		enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    		try {
    			jbInit();
    		}catch (Exception e) {
    			e.printStackTrace();
    		}
    		ServerListen();
    	}
    	
    	/**Component initialization*/
    	private void jbInit() throws Exception{
    		txtInput.setText("I'm the server.");
    		txtInput.setBounds(new Rectangle(42, 234, 196, 34));
    		
    //		setIconImage(Toolkit.getDefaultToolkit().createImage(
    //				ChatServer.class.getResource("[Your Icon]")));
    		contentPane = (JPanel)this.getContentPane();
    		contentPane.setLayout(null);
    		this.setSize(new Dimension(450, 350));
    		this.setTitle("Chat Server");
    		btnSend.setText("Send");
    		btnSend.setBounds(new Rectangle(286, 235, 98, 35));
    		btnSend.addActionListener(new ActionListener() {
    			public void actionPerformed(ActionEvent e) {
    				btnSend_actionPerformed(e);
    			}
    		});
    		lstMsg.setBounds(new Rectangle(42, 32, 319, 192));
    		contentPane.add(txtInput,null);
    		contentPane.add(btnSend,null);
    		contentPane.add(lstMsg,null);
    	}
    	/**Overridden so we can exit when window is closed*/
    	protected void processWindowEvent(WindowEvent e) {
    		super.processWindowEvent(e);
    		if(e.getID()==WindowEvent.WINDOW_CLOSING) {
    			System.exit(0);
    		}
    	}
    	
    	public static void main(String[] args) {
    		ChatServer server = new ChatServer();
    		server.show();
    	}
    	
    	public void processMsg(String str) {
    		this.lstMsg.add(str);
    	}
    	
    	void btnSend_actionPerformed(ActionEvent e) {
    		for (int i = 0; i < clients.size(); i++) {
    			Connection c = (Connection)clients.get(i);
    			try {
    				c.sendMsg(this.txtInput.getText());
    			}catch (Exception ee) {}
    		}
    	}
    	
    	public final static int DEFAULT_PORT = 6543;
    	protected ServerSocket listen_socket;
    	Thread thread;
    	java.util.Vector clients;
    	
    	//create a ServerSocket to listen for connection,start the thread
    	public void ServerListen() {
    		try {
    			listen_socket = new ServerSocket(DEFAULT_PORT);
    		}catch (IOException e) {
    			e.printStackTrace();
    		}
    		processMsg("Server: listening on port "+DEFAULT_PORT);
    		clients = new Vector(); 
    		thread = new Thread(this);
    		thread.start();
    	}
    	
    	/**the body of the server thread. Loop forever,listening for and
    	 * accepting connections from clients. For each connection ,
    	 * create a Connection object to handle communication through
    	 * the new Socket
    	 */
    	public void run() {
    		try {
    			while(true) {
    				Socket client_socket = listen_socket.accept();
    				Connection c = new Connection(client_socket,this);
    				clients.add(c);
    				processMsg("One Client Comes in");
    			}
    		}catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    }
    
    //This class is the thread that handles all communication with a client 
    class Connection extends Thread{
    	protected Socket client;
    	protected BufferedReader in;
    	protected PrintWriter out;
    	ChatServer server;
    	
    	//Initialize the streams and start the thread
    	public Connection(Socket client_socket,ChatServer server_frame) {
    		client = client_socket;
    		server = server_frame;
    		try {
    			in= new BufferedReader(
    					new InputStreamReader(client.getInputStream()));
    			out = new PrintWriter(client.getOutputStream());
    		}catch (IOException e) {
    			e.printStackTrace();
    			return;
    		}
    		this.start();
    	}
    	
    	//Provide the service,read a line
    	public void run() {
    		String line;
    		try {
    			for(;;) {
    				line = receiveMsg();
    				server.processMsg(line);
    				if(line == null)break;
    			}
    		}
    		catch (IOException e) {;}
    		finally {
    			try {
    				client.close();
    			}catch (IOException e2) {;}
    		}
    	}
    	
    	public void sendMsg(String msg) throws IOException{
    		out.println(msg);
    		out.flush();
    	}
    	
    	public String receiveMsg() throws IOException{
    		String msg = new String();
    		try {
    			msg = in.readLine();
    		}catch (IOException e) {
    			e.printStackTrace();
    		}
    		return msg;
    	}
    }

**客户机程序：**

import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    import java.net.*;
    import java.io.*;
    
    public class ChatClient extends JFrame implements Runnable{
    	boolean isStandalone = false;
    	public ChatClient() {
    		enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    		try {
    			jbInit();
    		}catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    	public void init() {
    		try {
    			jbInit();
    		}catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    	
    	public static void main(String[] args) {
    		ChatClient c = new ChatClient();
    		c.show();
    	}
    	
    	JPanel contentPane;
    	JTextField txtInput  = new JTextField();
    	JButton btnSend = new JButton();
    	JButton btnStart = new JButton();
    	List lstMsg = new List();
    	
    	private void jbInit() throws Exception{
    		txtInput.setText("I'm a client.");
    		txtInput.setBounds(new Rectangle(42, 234, 196, 34));
    		contentPane = (JPanel)this.getContentPane();
    		contentPane.setLayout(null);
    		this.setSize(new Dimension(550, 350));
    		this.setTitle("Chat Client");
    		btnSend.setText("Send");
    		btnSend.setBounds(new Rectangle(258, 235, 70, 35));
    		btnSend.addActionListener(new ActionListener() {
    			public void actionPerformed(ActionEvent e) {
    				btnSend_actionPerformed(e);
    			}
    		});
    		
    		btnStart.setText("Connect to Server");
    		btnStart.setBounds(new Rectangle(338, 235, 150, 35));
    		btnStart.addActionListener(new ActionListener() {
    			public void actionPerformed(ActionEvent e) {
    				btnStart_actionPerformed(e);
    			}
    		});
    		lstMsg.setBounds(new Rectangle(42, 32, 319, 192));
    		contentPane.add(txtInput, null);
    		contentPane.add(btnSend, null);
    		contentPane.add(btnStart, null);
    		contentPane.add(lstMsg, null);
    	}
    	
    	void btnSend_actionPerformed(ActionEvent e) {
    		if(txtInput.getText().length()!=0) {
    			try {
    				sendMsg(txtInput.getText());
    			}catch (IOException ee) {
    				processMsg(ee.toString());
    			}
    		}
    	}
    	
    	void btnStart_actionPerformed(ActionEvent e) {
    		this.startConnect();
    	}
    	
    	Socket sock;
    	Thread thread;
    	BufferedReader in;
    	PrintWriter out;
    	public final static int DEFAULT_PORT = 6543;
    	boolean bConnected;
    	
    	public void startConnect() {
    		bConnected = false;
    		try {
    			sock = new Socket("127.0.0.1",DEFAULT_PORT);
    			bConnected = true;
    			processMsg("Connection ok");
    			in = new BufferedReader(new InputStreamReader(
    					sock.getInputStream()));
    			out = new PrintWriter(sock.getOutputStream());
    		}catch (IOException e) {
    			e.printStackTrace();
    			processMsg("Connection failed");
    		}
    		if(thread == null) {
    			thread = new Thread(this);
    			thread.start();
    		}
    	}
    	
    	public void run() {
    		while(true) {
    			try {
    				String msg = receiveMsg();
    				Thread.sleep(100L);
    				if(msg!=null) {
    					processMsg(msg);
    				}
    			}catch (IOException e) {
    				e.printStackTrace();
    			}catch (InterruptedException e) {}
    		}
    	}
    	
    	public void sendMsg(String msg) throws IOException{
    		out.println(msg);
    		out.flush();
    	}
    	
    	public String receiveMsg() throws IOException {
    		String msg = new String();
    		try {
    			msg = in.readLine();
    		}catch (IOException e) {
    			e.printStackTrace();
    		}
    		return msg;
    	}
    	
    	public void processMsg(String str) {
    		this.lstMsg.add(str);
    	}
    	
    	//static initializer for setting look & feel
    //	static {
    //		try {
    //			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    //			UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
    //		}catch (Exception e) {}
    //	}
    }

程序结果，图中有三个客户机：

![70][]

[70]: /images/20220530/b7accdb0aa7e4326887bbf982794c531.png