本文小编为大家详细介绍“Java NIO怎么实现聊天室程序”，内容详细，步骤清晰，细节处理妥当，希望这篇“Java NIO怎么实现聊天室程序”文章能帮助大家解决疑惑，下面跟着小编的思路慢慢深入，一起来学习新知识吧。
服务端：
package test.javanio; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.nio.channels.SelectionKey; import java.nio.channels.Selector; import java.nio.channels.ServerSocketChannel; import java.nio.channels.SocketChannel; import java.util.Date; import java.util.Iterator; import java.util.logging.Level; import java.util.logging.Logger; public class MySocketServer implements Runnable { private boolean running; private Selector selector; String writeMsg; StringBuffer sb = new StringBuffer(); SelectionKey ssckey; public MySocketServer() { running = true; } public void init() { try { selector = Selector.open(); ServerSocketChannel ssc = ServerSocketChannel.open(); ssc.configureBlocking(false); ssc.socket().bind(new InetSocketAddress(2345)); ssckey = ssc.register(selector, SelectionKey.OP_ACCEPT); System.out.println("server is starting..." + new Date()); } catch (IOException ex) { Logger.getLogger(MySocketServer.class.getName()).log(Level.SEVERE, null, ex); } } public static void main(String[] args) { MySocketServer server = new MySocketServer(); new Thread(server).start(); } public void execute() { try { while (running) { int num = selector.select(); if (num > 0) { Iterator<SelectionKey> it = selector.selectedKeys() .iterator(); while (it.hasNext()) { SelectionKey key = it.next(); it.remove(); if (!key.isValid()) continue; if (key.isAcceptable()) { System.out.println("isAcceptable"); getConn(key); } else if (key.isReadable()) { System.out.println("isReadable"); readMsg(key); } else if (key.isValid() && key.isWritable()) { if (writeMsg != null) { System.out.println("isWritable"); writeMsg(key); } } else break; } } Thread.yield(); } } catch (IOException ex) { Logger.getLogger(MySocketServer.class.getName()).log(Level.SEVERE, null, ex); } } private void getConn(SelectionKey key) throws IOException { ServerSocketChannel ssc = (ServerSocketChannel) key.channel(); SocketChannel sc = ssc.accept(); sc.configureBlocking(false); sc.register(selector, SelectionKey.OP_READ); System.out.println("build connection :" + sc.socket().getRemoteSocketAddress()); } private void readMsg(SelectionKey key) throws IOException { sb.delete(0, sb.length()); SocketChannel sc = (SocketChannel) key.channel(); System.out.print(sc.socket().getRemoteSocketAddress() + " "); ByteBuffer buffer = ByteBuffer.allocate(1024); buffer.clear(); int len = 0; StringBuffer sb = new StringBuffer(); while ((len = sc.read(buffer)) > 0) { buffer.flip(); sb.append(new String(buffer.array(), 0, len)); } if (sb.length() > 0) System.out.println("get from client:" + sb.toString()); if (sb.toString().trim().toLowerCase().equals("quit")) { sc.write(ByteBuffer.wrap("BYE".getBytes())); System.out.println("client is closed " + sc.socket().getRemoteSocketAddress()); key.cancel(); sc.close(); sc.socket().close(); } else { String toMsg = sc.socket().getRemoteSocketAddress() + "said:" + sb.toString(); System.out.println(toMsg); writeMsg = toMsg; Iterator<SelectionKey> it = key.selector().keys().iterator(); while (it.hasNext()) { SelectionKey skey = it.next(); if (skey != key && skey != ssckey) { if (skey.attachment() != null) { String str = (String) skey.attachment(); skey.attach(str + toMsg); } else { skey.attach(toMsg); } skey .interestOps(skey.interestOps() | SelectionKey.OP_WRITE); } } selector.wakeup();// 可有可无 } } public void run() { init(); execute(); } private void writeMsg(SelectionKey key) throws IOException { System.out.println("++++enter write+++"); SocketChannel sc = (SocketChannel) key.channel(); String str = (String) key.attachment(); sc.write(ByteBuffer.wrap(str.getBytes())); key.interestOps(SelectionKey.OP_READ); } }客户端：
package test.javanio; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.nio.channels.Selector; import java.nio.channels.SocketChannel; import java.util.logging.Level; import java.util.logging.Logger; import java.util.Currency.*; public class MySocketClient implements Runnable { Selector selector; boolean running; SocketChannel sc; public MySocketClient() { running = true; } public void init() { try { sc = SocketChannel.open(); sc.configureBlocking(false); sc.connect(new InetSocketAddress("localhost", 2345)); } catch (IOException ex) { Logger.getLogger(MySocketClient.class.getName()).log(Level.SEVERE, null, ex); } } public static void main(String[] args) { MySocketClient client = new MySocketClient(); new Thread(client).start(); } public void execute() { int num = 0; try { while (!sc.finishConnect()) { } } catch (IOException ex) { Logger.getLogger(MySocketClient.class.getName()).log(Level.SEVERE, null, ex); } ReadKeyBoard rkb = new ReadKeyBoard(); new Thread(rkb).start(); while (running) { try { ByteBuffer buffer = ByteBuffer.allocate(1024); buffer.clear(); StringBuffer sb = new StringBuffer(); Thread.sleep(500); while ((num = sc.read(buffer)) > 0) { sb.append(new String(buffer.array(), 0, num)); buffer.clear(); } if (sb.length() > 0) System.out.println(sb.toString()); if (sb.toString().toLowerCase().trim().equals("bye")) { System.out.println("closed...."); sc.close(); sc.socket().close(); rkb.close(); running = false; } } catch (InterruptedException ex) { Logger.getLogger(MySocketClient.class.getName()).log( Level.SEVERE, null, ex); } catch (IOException ex) { Logger.getLogger(MySocketClient.class.getName()).log( Level.SEVERE, null, ex); } } } public void run() { init(); execute(); } class ReadKeyBoard implements Runnable { boolean running2 = true; public ReadKeyBoard() { } public void close() { running2 = false; } public void run() { BufferedReader reader = new BufferedReader(new InputStreamReader( System.in)); while (running2) { try { System.out.println("enter some commands:"); String str = reader.readLine(); sc.write(ByteBuffer.wrap(str.getBytes())); } catch (IOException ex) { Logger.getLogger(ReadKeyBoard.class.getName()).log( Level.SEVERE, null, ex); } } } } }读到这里，这篇“Java NIO怎么实现聊天室程序”文章已经介绍完毕，想要掌握这篇文章的知识点还需要大家自己动手实践使用过才能领会，如果想了解更多相关内容的文章，欢迎关注编程网行业资讯频道。
