NIO 入门 实例

NIOServer

package com.nio.test;import java.io.IOException;import java.net.InetSocketAddress;import java.net.ServerSocket;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.Iterator;import java.util.Set;public class NIOServer implements Runnable{privateServerSocketChannel serverSocketChannel;privateServerSocket serverSocket;privateSelector selector;/*标识数字*/      private  int flag = 0;      /*缓冲区大小*/      private  int BLOCK = 4096;      /*接受数据缓冲区*/      private  ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);      /*发送数据缓冲区*/      private  ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK); public NIOServer(int port) {  try { //打开服务器管道 serverSocketChannel = ServerSocketChannel.open(); // 服务器配置为非阻塞  serverSocketChannel.configureBlocking(false); //检索与此通道关联的服务器套接字  serverSocket=serverSocketChannel.socket(); //进行服务的绑定 serverSocket.bind(new InetSocketAddress(port)); //通过open获取selector selector=Selector.open();// 注册到selector，等待连接  serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT); System.out.println("bind 8888 port.........");  } catch (IOException e) {e.printStackTrace();}}public void run() {while (true) {// 选择一组键，并且相应的通道已经打开  try {selector.select();Set<SelectionKey> selectionKeys = selector.selectedKeys();Iterator<SelectionKey>iterator = selectionKeys.iterator();while (iterator.hasNext()) {SelectionKey selectionKey = (SelectionKey) iterator.next();iterator.remove();if (flag == 10) {System.exit(0);}handler(selectionKey);}} catch (Exception e) {System.exit(0);}}}private void handler(SelectionKey selectionKey) throws Exception { // 接受请求          ServerSocketChannel server = null;          SocketChannel client = null;          String receiveText;          String sendText;          int count=0;  if (selectionKey.isAcceptable()) {server =(ServerSocketChannel) selectionKey.channel();    client = server.accept();    client.configureBlocking(false);    client.register(selector, SelectionKey.OP_READ);}else if (selectionKey.isReadable()) {client =(SocketChannel) selectionKey.channel();receivebuffer.clear();count =client.read(receivebuffer);if (count > 0) {receiveText = new String(receivebuffer.array(),0,count);                  System.out.println("服务器端接受客户端数据--:"+receiveText);                  client.register(selector, SelectionKey.OP_WRITE);  }}else if (selectionKey.isWritable()) {sendbuffer.clear();client=(SocketChannel) selectionKey.channel();sendText="message form server ---"+flag++;sendbuffer.put(sendText.getBytes());sendbuffer.flip();//client.write(sendbuffer);System.out.println("服务器端向客户端发送数据---:"+sendText);client.register(selector, SelectionKey.OP_READ);}else if (selectionKey.isConnectable()) {System.out.println("selectionKey is Connectable .");}}public static void main(String[] args) {int port = 8888;NIOServer nioServer = new NIOServer(port);new Thread(nioServer).start();}}

NIOClient

package com.nio.test;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.SocketChannel;import java.util.Iterator;import java.util.Set;public class NIOClient implements Runnable{privateSocketChannel serverSocket;privateSelector selector;/*标识数字*/      private  int flag = 0;      /*缓冲区大小*/      private  int BLOCK = 4096;      /*接受数据缓冲区*/      private  ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);      /*发送数据缓冲区*/      private  ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK); public NIOClient(int port) {  try { serverSocket = SocketChannel.open(); // 配置为非阻塞  serverSocket.configureBlocking(false); //进行连接 serverSocket.connect(new InetSocketAddress(port)); //通过open获取selector selector=Selector.open();// 注册到selector，等待连接  serverSocket.register(selector, SelectionKey.OP_CONNECT); System.out.println("connet 8888 port.........");  } catch (IOException e) {e.printStackTrace();}}public void run() {while (true) {// 选择一组键，并且相应的通道已经打开  try {selector.select();Set<SelectionKey> selectionKeys = selector.selectedKeys();Iterator<SelectionKey>iterator = selectionKeys.iterator();while (iterator.hasNext()) {SelectionKey selectionKey = (SelectionKey) iterator.next();iterator.remove();if (flag == 10) {System.exit(0);}handler(selectionKey);}} catch (Exception e) {e.printStackTrace();System.exit(0);}}}private void handler(SelectionKey selectionKey) throws Exception {        SocketChannel client = null;          String receiveText;          String sendText;          int count=0;  if (selectionKey.isConnectable()) {System.out.println("client connect");             client = (SocketChannel) selectionKey.channel();             // 判断此通道上是否正在进行连接操作。             // 完成套接字通道的连接过程。             if (client.isConnectionPending()) {                 client.finishConnect();                 System.out.println("完成连接!");                 sendbuffer.clear();                 sendbuffer.put("Hello,Server".getBytes());                 sendbuffer.flip();                 client.write(sendbuffer);             }             client.register(selector, SelectionKey.OP_READ); }else if (selectionKey.isReadable()) {client =(SocketChannel) selectionKey.channel();receivebuffer.clear();count =client.read(receivebuffer);if (count > 0) {receiveText = new String(receivebuffer.array(),0,count);                  System.out.println("客户端接受服务器端数据--:"+receiveText);                  client.register(selector, SelectionKey.OP_WRITE);  }}else if (selectionKey.isWritable()) {sendbuffer.clear();client=(SocketChannel) selectionKey.channel();sendText="message form client ---"+flag++;sendbuffer.put(sendText.getBytes());sendbuffer.flip();//client.write(sendbuffer);System.out.println("客户端向服务器端发送数据---:"+sendText);client.register(selector, SelectionKey.OP_READ);}else if (selectionKey.isConnectable()) {System.out.println("selectionKey is Connectable .");}}public static void main(String[] args) {int port = 8888;NIOClient nioServer = new NIOClient(port);new Thread(nioServer).start();}}