netty示例NIO示例

package com.hfkj.netty_test.io.nio; 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.Scanner; import java.util.Set; public class NioClient { private static final int BLOCK_SIZE = 4096; private static ByteBuffer sendBuffer = ByteBuffer.allocate(BLOCK_SIZE); private static ByteBuffer receiveBuffer = ByteBuffer.allocate(BLOCK_SIZE); // 定义检查SocketChanel的Selector对象 private Selector selector; // 客户端SocketChannel private SocketChannel socketChannel; // 监听的端口号 private int port = 8787; private String ip = "127.0.0.1"; public NioClient() throws IOException { selector = Selector.open(); InetSocketAddress isa = new InetSocketAddress(ip, port); socketChannel = SocketChannel.open(); // 设置该SocketChannel为非阻塞的方式工作 socketChannel.configureBlocking(false); // 将SocketChannel对象注册到Selector socketChannel.register(selector, SelectionKey.OP_CONNECT); socketChannel.connect(isa); } public void listener() throws IOException, InterruptedException { while (true) { // 选择一组键 selector.select(); Set<SelectionKey> selectionKeys = selector.selectedKeys(); Iterator<SelectionKey> keys = selectionKeys.iterator(); while (keys.hasNext()) { SelectionKey key = keys.next(); processKey(key); } selectionKeys.clear(); Thread.sleep(3000); } } public void processKey(SelectionKey key) throws IOException { // 判断此键的通道是否已完成其套接字连接操作 if (key.isConnectable()) { System.out.println("Client: already connected."); socketChannel = (SocketChannel) key.channel(); // 判断该通道是否进行连接过程、完成连接过程 if (socketChannel.isConnectionPending()) { System.out.println("Client: 已经连接"); socketChannel.finishConnect(); sendBuffer.clear(); sendBuffer.put("hello nio server".getBytes()); sendBuffer.flip(); socketChannel.write(sendBuffer); // 将数据写入该通道 // 将SocketChannel对象注册到Selector且通道是准备读数据的状态 socketChannel.register(selector, SelectionKey.OP_WRITE); } } else if (key.isReadable()) { socketChannel = (SocketChannel) key.channel(); receiveBuffer.clear(); int count = socketChannel.read(receiveBuffer); if (count > 0) { String receiveMessage = new String(receiveBuffer.array(), 0, count); // System.out.println("Client：接收到来自Server的消息，" + // receiveMessage); // 将SocketChannel对象注册到Selector且通道是准备写数据的状态 socketChannel.register(selector, SelectionKey.OP_WRITE); } } else if (key.isWritable()) { socketChannel = (SocketChannel) key.channel(); // String sendText = "hello server,key.."; // sendBuffer.clear(); // 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(); // // // socketChannel.write(sendBuffer); Scanner scanner=new Scanner(System.in);//控制台输入对象 System.out.println("请输入第一个整数:"); String a = scanner.nextLine();//从控制台输入第一个数 sendBuffer.clear(); sendBuffer.put(a.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(); // socketChannel.write(sendBuffer); System.out.println("Client:客户端向服务器端发送数据--：" + a); socketChannel.register(selector, SelectionKey.OP_WRITE); // } } } public static void main(String[] args) { try { // Scanner scan = new Scanner(System.in); //// if (scan.hasNextLine()) { // String line = scan.nextLine(); // System.out.println("你输入的是："+line); //// } new NioClient().listener(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }