Java|Java NIO实现多人聊天室 JavaNIO实现多人聊天室

【Java|Java NIO实现多人聊天室】本文实例为大家分享了Java NIO实现多人聊天室的具体代码，供大家参考，具体内容如下
1. 服务器端代码
ChatServer类：

package nio.test.server; import java.io.Closeable; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.nio.channels.*; import java.nio.charset.Charset; import java.util.Set; public class ChatServer {private static final int DEFAULT_PORT = 8888; private static final String QUIT = "quit"; private static final int BUFFER = 1024; private ServerSocketChannel serverSocketChannel; //服务器端用于处理IO的通道private Selector selector; private ByteBuffer byteBufferReader = ByteBuffer.allocate(BUFFER); //用来读取消息private ByteBuffer byteBufferWriter = ByteBuffer.allocate(BUFFER); //用来转发消息时写入其他通道的缓冲区private Charset charset = Charset.forName("UTF-8"); //标准化编码解码private int port; public ChatServer(){this(DEFAULT_PORT); }public ChatServer(int port){this.port = port; }private void start(){try {serverSocketChannel = ServerSocketChannel.open(); //创建服务器套接字通道serverSocketChannel.configureBlocking(false); //设置为非阻塞式调用serverSocketChannel.socket().bind(new InetSocketAddress(port)); selector = Selector.open(); //打开选择器serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT); System.out.println("启动服务器，监听端口：" + port + "..."); while (true) {selector.select(); //selectionKeys包含了select()接收到的所有事件Set selectionKeys = selector.selectedKeys(); for(SelectionKey key : selectionKeys){//处理被触发的事件handles(key); }selectionKeys.clear(); //把集合清空}} catch (IOException e) {e.printStackTrace(); }finally {close(selector); //启到既关闭selector又关闭通道的作用}}/*** 处理被触发的事件* @param key 每当通道被选择器注册时，都会创建一个选择键* @throws IOException*/private void handles(SelectionKey key) throws IOException {// 触发 ACCEPT事件 --- 和客户端建立了连接if(key.isAcceptable()){ServerSocketChannel server = (ServerSocketChannel) key.channel(); SocketChannel client = server.accept(); client.configureBlocking(false); client.register(selector, SelectionKey.OP_READ); System.out.println(getClientName(client) + "已连接"); }// 触发 READ事件 --- 客户端发送了消息给服务器端else if(key.isReadable()){SocketChannel client = (SocketChannel) key.channel(); String fwdMsg = receive(client); //读取客户端消息if(fwdMsg.isEmpty()){ //客户端异常key.cancel(); //不再监视这个通道上的read事件selector.wakeup(); }else {forwardMessage(client, fwdMsg); //转发客户端消息// 检查用户是否退出if(readyToQuit(fwdMsg)){key.cancel(); //解除监听selector.wakeup(); System.out.println(getClientName(client) + "已断开"); }}}}/*** 用于转发消息* @param client* @param fwdMsg* @throws IOException*/private void forwardMessage(SocketChannel client, String fwdMsg) throws IOException {for(SelectionKey key : selector.keys()){Channel connectedClient = key.channel(); if(connectedClient instanceof ServerSocketChannel) continue; if(key.isValid() && !client.equals(connectedClient)) {byteBufferWriter.clear(); byteBufferWriter.put(charset.encode((getClientName(client)) + ":" + fwdMsg)); byteBufferWriter.flip(); //写转读while(byteBufferWriter.hasRemaining()){((SocketChannel)connectedClient).write(byteBufferWriter); }}}}private String receive(SocketChannel client) throws IOException {byteBufferReader.clear(); while(client.read(byteBufferReader) > 0); byteBufferReader.flip(); return String.valueOf(charset.decode(byteBufferReader)); }private String getClientName(SocketChannel client){return "客户端[" + client.socket().getPort() + "]"; }private boolean readyToQuit(String msg){return QUIT.equals(msg); }private void close(Closeable closeable){if(closeable != null){try {closeable.close(); } catch (IOException e) {e.printStackTrace(); }}}public static void main(String[] args) {ChatServer chatServer = new ChatServer(6666); chatServer.start(); }}

2. 客户端代码
ChatClient类：

package nio.test.client; import java.io.Closeable; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.nio.channels.ClosedSelectorException; import java.nio.channels.SelectionKey; import java.nio.channels.Selector; import java.nio.channels.SocketChannel; import java.nio.charset.Charset; import java.util.Set; public class ChatClient {private static final String DEFAULT_SERVER_HOST = "127.0.0.1"; private static final int DEFAULT_SERVER_PORT = 6666; private static final String QUIT = "quit"; private static final int BUFFER = 1024; private String host; private int port; private SocketChannel client; private ByteBuffer byteBufferReader = ByteBuffer.allocate(BUFFER); private ByteBuffer byteBufferWriter = ByteBuffer.allocate(BUFFER); private Selector selector; private Charset charset = Charset.forName("UTF-8"); public ChatClient(){this(DEFAULT_SERVER_HOST, DEFAULT_SERVER_PORT); }public ChatClient(String host, int port){this.host = host; this.port = port; }public boolean readyToQuit(String msg){return QUIT.equals(msg); }private void close(Closeable closeable){if(closeable != null){try {closeable.close(); } catch (IOException e) {e.printStackTrace(); }}}private void start(){try {client = SocketChannel.open(); client.configureBlocking(false); selector = Selector.open(); client.register(selector, SelectionKey.OP_CONNECT); client.connect(new InetSocketAddress(host, port)); while(true){selector.select(); Set selectionKeys = selector.selectedKeys(); for(SelectionKey key : selectionKeys){handles(key); }selectionKeys.clear(); }} catch (IOException e) {e.printStackTrace(); } catch (ClosedSelectorException e){//用户正常退出}finally {close(selector); }}private void handles(SelectionKey key) throws IOException {// CONNECT事件连接就绪事件if(key.isConnectable()){SocketChannel client = (SocketChannel)key.channel(); if(client.isConnectionPending()){//连接处于就绪状态client.finishConnect(); // 处理用户的输入信息new Thread(new UserInputHandler(this)).start(); }client.register(selector, SelectionKey.OP_READ); }// READ事件服务器转发消息else if(key.isReadable()){SocketChannel client = (SocketChannel)key.channel(); String msg = receive(client); if(msg.isEmpty()){// 服务器出现异常close(selector); }else{System.out.println(msg); }}}public void send(String msg) throws IOException {if(msg.isEmpty()){return ; }else{byteBufferWriter.clear(); byteBufferWriter.put(charset.encode(msg)); byteBufferWriter.flip(); while(byteBufferWriter.hasRemaining()){client.write(byteBufferWriter); }//检查用户是否准备退出if(readyToQuit(msg)){close(selector); }}}private String receive(SocketChannel client) throws IOException {byteBufferReader.clear(); while(client.read(byteBufferReader) > 0); byteBufferReader.flip(); return String.valueOf(charset.decode(byteBufferReader)); }public static void main(String[] args) {ChatClient chatClient = new ChatClient(); chatClient.start(); }}

UserInputHandler类：

package nio.test.client; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class UserInputHandler implements Runnable{private ChatClient chatclient; public UserInputHandler(ChatClient chatClient){this.chatclient = chatClient; }/**r**/@Overridepublic void run() {try {//等待用户输入的消息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(); }}}

3. 执行效果截图