java nio 非阻塞

server端编写：

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 {/*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);private  Selector selector;public NIOServer(int port) throws IOException {// 打开服务器套接字通道ServerSocketChannel 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 serverSocket = serverSocketChannel.socket();// 进行服务的绑定serverSocket.bind(new InetSocketAddress(port));// 通过open()方法找到Selectorselector = Selector.open();// 注册到selector，等待连接serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);System.out.println("Server Start----8888:");}// 监听private void listen() throws IOException {while (true) {// 选择一组键，并且相应的通道已经打开selector.select();// 返回此选择器的已选择键集。Set<SelectionKey> selectionKeys = selector.selectedKeys();Iterator<SelectionKey> iterator = selectionKeys.iterator();while (iterator.hasNext()) {SelectionKey selectionKey = iterator.next();iterator.remove();handleKey(selectionKey);}}}// 处理请求private void handleKey(SelectionKey selectionKey) throws IOException {// 接受请求ServerSocketChannel server = null;SocketChannel client = null;String receiveText;String sendText;int count=0;// 测试此键的通道是否已准备好接受新的套接字连接。if (selectionKey.isAcceptable()) {// 返回为之创建此键的通道。server = (ServerSocketChannel) selectionKey.channel();// 接受到此通道套接字的连接。// 此方法返回的套接字通道（如果有）将处于阻塞模式。client = server.accept();// 配置为非阻塞client.configureBlocking(false);// 注册到selector，等待连接client.register(selector, SelectionKey.OP_READ);} else if (selectionKey.isReadable()) {// 返回为之创建此键的通道。client = (SocketChannel) selectionKey.channel();//将缓冲区清空以备下次读取receivebuffer.clear();//读取服务器发送来的数据到缓冲区中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()) {//将缓冲区清空以备下次写入sendbuffer.clear();// 返回为之创建此键的通道。client = (SocketChannel) selectionKey.channel();sendText="message from server--" + flag++;//向缓冲区中输入数据sendbuffer.put(sendText.getBytes()); //将缓冲区各标志复位,因为向里面put了数据标志被改变要想从中读取数据发向服务器,就要复位sendbuffer.flip();//输出到通道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);}}/** * @param args * @throws IOException */public static void main(String[] args) throws IOException {// TODO Auto-generated method stubint port = 8888;NIOServer server = new NIOServer(port);server.listen();}}

client端编写

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 {/*标识数字*/private static int flag = 0;/*缓冲区大小*/private static int BLOCK = 4096;/*接受数据缓冲区*/private static ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);/*发送数据缓冲区*/private static ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK);/*服务器端地址*/private final static InetSocketAddress SERVER_ADDRESS = new InetSocketAddress("localhost", 8888);public static void main(String[] args) throws IOException {// TODO Auto-generated method stub// 打开socket通道SocketChannel socketChannel = SocketChannel.open();// 设置为非阻塞方式socketChannel.configureBlocking(false);// 打开选择器Selector selector = Selector.open();// 注册连接服务端socket动作socketChannel.register(selector, SelectionKey.OP_CONNECT);// 连接socketChannel.connect(SERVER_ADDRESS);// 分配缓冲区大小内存Set<SelectionKey> selectionKeys;Iterator<SelectionKey> iterator;SelectionKey selectionKey;SocketChannel client;String receiveText;String sendText;int count=0;while (true) {//选择一组键，其相应的通道已为 I/O 操作准备就绪。//此方法执行处于阻塞模式的选择操作。selector.select();//返回此选择器的已选择键集。selectionKeys = selector.selectedKeys();//System.out.println(selectionKeys.size());iterator = selectionKeys.iterator();while (iterator.hasNext()) {selectionKey = iterator.next();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();//将缓冲区清空以备下次读取receivebuffer.clear();//读取服务器发送来的数据到缓冲区中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 from client--" + (flag++);sendbuffer.put(sendText.getBytes()); //将缓冲区各标志复位,因为向里面put了数据标志被改变要想从中读取数据发向服务器,就要复位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);}}selectionKeys.clear();}}}