本文实例讲述了Java基于Socket实现简单的多线程回显服务器功能。分享给大家供大家参考，具体如下：

需要两个类，一个是EchoServer，代表服务器。另外一个是EchoServerClient，代表客户端。代码如下：

package interview;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.ServerSocket;import java.net.Socket;public class EchoServer { public static void main(String []args) throws IOException{ ServerSocket server = new ServerSocket(6789); while(true){ Socket client = server.accept(); ClientHandler handler = new ClientHandler(client); new Thread(handler).start(); } } public static class ClientHandler implements Runnable{ private Socket client; @Override public void run() { InputStreamReader isr = null; try { isr = new InputStreamReader(client.getInputStream()); BufferedReader br = new BufferedReader(isr); PrintWriter pw = new PrintWriter(client.getOutputStream()); String msg = br.readLine(); System.out.println("收到" + client.getInetAddress() + "发送的" + msg); pw.println("收到了你发的" + msg); pw.flush(); } catch (IOException e) { e.printStackTrace(); } } public ClientHandler(Socket client){ this.client = client; } }}

下面是客户端代码：

package interview;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.Socket;import java.net.UnknownHostException;import java.util.Scanner;public class EchoServerClient { public static void main(String []args) throws UnknownHostException, IOException{ Socket client = new Socket("127.0.0.1", 6789); Scanner sc = new Scanner(System.in); System.out.print("请输入要发送的内容："); String msg = sc.nextLine(); sc.close(); PrintWriter pw = new PrintWriter(client.getOutputStream()); pw.println(msg); pw.flush(); InputStreamReader isr = new InputStreamReader(client.getInputStream()); BufferedReader br = new BufferedReader(isr); System.out.println("服务器返回：" + br.readLine()); client.close(); }}

NIO多路复用套接字方法如下：

package interview;import java.io.IOException;import java.net.InetSocketAddress;import java.nio.ByteBuffer;import java.nio.CharBuffer;import java.nio.channels.SelectionKey;import java.nio.channels.Selector;import java.nio.channels.ServerSocketChannel;import java.nio.channels.SocketChannel;import java.nio.charset.CharacterCodingException;import java.nio.charset.Charset;import java.nio.charset.CharsetDecoder;import java.nio.charset.CharsetEncoder;import java.util.Iterator;public class EchoServerNIO { private static ServerSocketChannel serverChannel = null; private static Selector selector = null;// 多路复用选择器 private static ByteBuffer buffer = null; // 缓冲区 public static void main(String []args) throws IOException{ init(); listen(); } static void init() throws IOException{ serverChannel = ServerSocketChannel.open(); buffer = ByteBuffer.allocate(1024); serverChannel.socket().bind(new InetSocketAddress(6789)); serverChannel.configureBlocking(false); selector = Selector.open(); serverChannel.register(selector, SelectionKey.OP_ACCEPT); } static void listen() throws IOException{ while(true){ if(selector.select(5000) != 0){ Iterator<SelectionKey> it = selector.selectedKeys().iterator(); while(it.hasNext()){ SelectionKey key = it.next(); it.remove(); handleKey(key); } } } } static void handleKey(SelectionKey key) throws IOException{ SocketChannel channel = null; if(key.isAcceptable()){ ServerSocketChannel serverChannel = (ServerSocketChannel)key.channel(); channel = serverChannel.accept(); channel.configureBlocking(false); channel.register(selector, SelectionKey.OP_READ); }else if(key.isReadable()){ channel = (SocketChannel)key.channel(); buffer.clear(); if(channel.read(buffer) > 0){ buffer.flip(); CharBuffer charBuffer = CharsetHelper.decode(buffer); String msg = charBuffer.toString(); System.out.println("收到" + channel.getRemoteAddress() + "的消息:" + msg); channel.write(CharsetHelper.encode(CharBuffer.wrap("received your msg:" + msg))); } } } public static class CharsetHelper{ private static final String UTF_8 = "UTF-8"; private static CharsetEncoder encoder = Charset.forName(UTF_8).newEncoder(); private static CharsetDecoder decoder = Charset.forName(UTF_8).newDecoder(); private CharsetHelper() { } public static ByteBuffer encode(CharBuffer in) throws CharacterCodingException{ return encoder.encode(in); } public static CharBuffer decode(ByteBuffer in) throws CharacterCodingException{ return decoder.decode(in); } }}

更多关于java相关内容感兴趣的读者可查看本站专题：《Java Socket编程技巧总结》、《Java文件与目录操作技巧汇总》、《Java数据结构与算法教程》、《Java操作DOM节点技巧总结》和《Java缓存操作技巧汇总》

希望本文所述对大家java程序设计有所帮助。