基于NIO的socket举例

package test.server; 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.Charset; import java.nio.charset.CharsetEncoder; import java.util.Iterator; import java.util.Set; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; public class ServerMain { private int num = 0; public static Selector sel; private ServerSocketChannel server; private ExecutorService pool; public ServerMain(int port, int num) throws IOException { sel = Selector.open();// 选择器(多路复用器) pool = Executors.newFixedThreadPool(num); server = ServerSocketChannel.open(); server.socket().bind(new InetSocketAddress(port)); server.configureBlocking(false);// 非阻塞 server.register(sel, SelectionKey.OP_ACCEPT);// 注册 this.run(); } public void run() { System.out.println("listen to port..."); try { for (;;) { sel.select(); //在这里会阻塞 Set<SelectionKey> readyKeys = sel.selectedKeys(); Iterator<SelectionKey> iterator = readyKeys.iterator(); while (iterator.hasNext()){ SelectionKey key = iterator.next(); iterator.remove(); this.process(key); } } } catch (IOException e) { e.printStackTrace(); } } public void process(SelectionKey key) throws IOException { if (key.isAcceptable()) { ServerSocketChannel server = (ServerSocketChannel)key.channel(); SocketChannel client = server.accept(); client.configureBlocking(false); client.register(ServerMain.sel, SelectionKey.OP_WRITE); } else if (key.isWritable()) { System.out.println(++num); CharsetEncoder encoder = Charset.forName("UTF-8").newEncoder(); SocketChannel channel = (SocketChannel) key.channel(); ByteBuffer block = encoder.encode(CharBuffer.wrap("connect to server...")); channel.write(block); if(key.isValid()) key.cancel(); // 注意,注销key否则selector一直选择 pool.execute(new TCPHandler()); } } public static void main(String[] args) throws IOException { new ServerMain(8888,200).run(); } }