NIO示例1

package com.mzj.nio.java;

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;

/**
 * Copyright (C),HTF<br>
 * NIO通信客户端
 * 
 * @author muzhongjiang
 * @date 2014年8月1日
 */
public class NIOClient {

    private static final int PORT = 8888;
    private static int BLOCK = 4096;// 缓冲区大小
    private static ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);// 接受数据缓冲区
    private static ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK);// 发送数据缓冲区
    private final static InetSocketAddress SERVER_ADDRESS = new InetSocketAddress("localhost", PORT);// 服务器端地址
    private static int flag = 0;// 标识数字

    public static void main(String[] args) throws IOException {
        
        SocketChannel socketChannel = SocketChannel.open();// 打开socket通道
        socketChannel.configureBlocking(false);// 设置为非阻塞方式
        Selector selector = Selector.open();// 打开选择器
        socketChannel.register(selector, SelectionKey.OP_CONNECT);// 注册连接服务端socket动作
        socketChannel.connect(SERVER_ADDRESS);// 连接
        // 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();
        }
    }
}

package com.mzj.nio.java;

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;

/**
 * Copyright (C),HTF<br>
 * NIO通信服务端
 * 
 * @author muzhongjiang
 * @date 2014年8月1日
 */
public class NIOServer {

    private static int PORT = 8888;
    private static int flag = 0;// 标识数字
    private static int BLOCK = 4096;// 缓冲区大小
    private static ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);// 接受数据缓冲区
    private static ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK);// 发送数据缓冲区
    private static Selector selector;

    public static void start() throws IOException {
        // 1.打开server端socket通道
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        // 2.server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Selector
        selector = Selector.open();
        // 注册到selector，等待连接
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
        System.err.println("Server Start----" + PORT);
        startListen();
    }

    // 监听
    private static void startListen() 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 static 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);
        }
    }

    public static void main(String[] args) throws IOException {
        start();
    }
}