BIO模型聊天室项目大体设计

BIO编程模型

• Acceptor是服务器端负责监听具体端口的Socket
• 每有一个客户端Client连接到服务器端，Acceptor就创建一个新的线程Handler来处理客户端发送的消息
• 每一个客户端都有一个唯一的Handler来对应处理其事务
• 为保证线程安全，简单地使用了synchronized来保证

时序图

服务器端Server代码实现

ChatServer实现

package server;import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.Map;public class ChatServer {//定义Socket需要监听的端口private int DEFAULT_PORT = 8888;private final String QUIT = "quit";private ServerSocket serverSocket;private Map<Integer, Writer> connectedClients;public ChatServer() {connectedClients = new HashMap<>();}public synchronized void addClient(Socket socket) throws IOException {if (socket != null) {int port = socket.getPort();BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));connectedClients.put(port, writer);System.out.println("客户端[" + port + "]已连接到服务器");}}public synchronized void removeClient(Socket socket) throws IOException {if (socket != null) {int port = socket.getPort();if (connectedClients.containsKey(port)) {connectedClients.get(port).close();}connectedClients.remove(port);System.out.println("客户端[" + port + "]已断开连接");}}public synchronized void forwardMessage(Socket socket, String fwdMsg) throws IOException {for (Integer id : connectedClients.keySet()) {if (!id.equals(socket.getPort())) {Writer writer = connectedClients.get(id);writer.write(fwdMsg);writer.flush();}}}public boolean readyToQuit(String msg) {return QUIT.equals(msg);}public synchronized void close() {if (serverSocket != null) {try {serverSocket.close();System.out.println("关闭serverSocket");} catch (IOException e) {e.printStackTrace();}}}public void start() {try {// 绑定监听端口serverSocket = new ServerSocket(DEFAULT_PORT);System.out.println("启动服务器，监听端口：" + DEFAULT_PORT + "...");while (true) {// 等待客户端连接Socket socket = serverSocket.accept();// 创建ChatHandler线程new Thread(new ChatHandler(this, socket)).start();}} catch (IOException e) {e.printStackTrace();} finally {close();}}public static void main(String[] args) {ChatServer server = new ChatServer();server.start();}}

ChatHanlder实现

package server;import java.io.*;
import java.net.Socket;public class ChatHandler implements Runnable {private ChatServer server;private Socket socket;public ChatHandler(ChatServer server, Socket socket) {this.server = server;this.socket = socket;}@Overridepublic void run() {try {// 存储新上线用户server.addClient(socket);// 读取用户发送的消息BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));String msg = null;while ((msg = reader.readLine()) != null) {String fwdMsg = "客户端[" + socket.getPort() + "]: " + msg + "\n";System.out.print(fwdMsg);// 将消息转发给聊天室里在线的其他用户server.forwardMessage(socket, fwdMsg);// 检查用户是否准备退出if (server.readyToQuit(msg)) {break;}}} catch (IOException e) {e.printStackTrace();} finally {try {server.removeClient(socket);} catch (IOException e) {e.printStackTrace();}}}
}

客户端Client代码实现

ChatClient实现

package client;import java.io.*;
import java.net.Socket;public class ChatClient {//定义目标服务器的主机名和端口private final String DEFAULT_SERVER_HOST = "127.0.0.1";private final int DEFAULT_SERVER_PORT = 8888;private final String QUIT = "quit";//定义Socket和输入流，输出流private Socket socket;private BufferedReader reader;private BufferedWriter writer;// 发送消息给服务器public void send(String msg) throws IOException {if (!socket.isOutputShutdown()) {writer.write(msg + "\n");writer.flush();}}// 从服务器接收消息public String receive() throws IOException {String msg = null;if (!socket.isInputShutdown()) {msg = reader.readLine();}return msg;}// 检查用户是否准备退出public boolean readyToQuit(String msg) {return QUIT.equals(msg);}public void close() {if (writer != null) {try {System.out.println("关闭socket");writer.close();} catch (IOException e) {e.printStackTrace();}}}public void start() {try {// 创建socketsocket = new Socket(DEFAULT_SERVER_HOST, DEFAULT_SERVER_PORT);// 创建IO流reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));// 处理用户的输入new Thread(new UserInputHandler(this)).start();// 读取服务器转发的消息String msg = null;while ((msg = receive()) != null) {System.out.println(msg);}} catch (IOException e) {e.printStackTrace();} finally {close();}}public static void main(String[] args) {ChatClient chatClient = new ChatClient();chatClient.start();}
}

UserInputHanlder实现

package client;import client.ChatClient;
import java.io.*;public class UserInputHandler implements Runnable {private ChatClient chatClient;public UserInputHandler(ChatClient chatClient) {this.chatClient = chatClient;}@Overridepublic void run() {try {// 等待用户输入消息BufferedReader consoleReader =new BufferedReader(new InputStreamReader(System.in));while (true) {String input = consoleReader.readLine();// 向服务器发送消息chatClient.send(input);// 检查用户是否准备退出if (chatClient.readyToQuit(input)) {break;}}} catch (IOException e) {e.printStackTrace();}}
}