NIO示例2

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.Date;
import java.util.Iterator;
import java.util.Set;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Copyright (C),HTF<br>
 * NIO客户端<br>
 * NIO：1.缓冲区、2.选择器、3.通道、4.SelectionKey（事件类型）<br>
 * 类似于AWT事件机制
 *
 * @author muzhongjiang
 * @date 2014年8月20日
 */
public class NIOClient {

    private final Logger LOG = LoggerFactory.getLogger(this.getClass());

    private final int BLOCK = 4096;// 缓冲区大小
    private ByteBuffer sendBuf = ByteBuffer.allocate(BLOCK);// 数据接收缓冲区
    private ByteBuffer receiveBuf = ByteBuffer.allocate(BLOCK);// 数据发送缓冲区
    private Selector selector;// 通道选择器
    private final InetSocketAddress SERVER_ADDRESS;

    /**
     * 构造方法
     *
     * @throws IOException
     */
    public NIOClient(String hostName, int port) throws IOException {
        SERVER_ADDRESS = new InetSocketAddress(hostName, port);
        this.start();
    }

    public void start() throws IOException {
        // 1.打开client端socket通道：
        SocketChannel socketChannel = SocketChannel.open();

        // 2.通道设置为非阻塞式：
        socketChannel.configureBlocking(false);

        // 4.获得通道选择器：
        selector = Selector.open();

        // 5.注册连接服务端的key：
        socketChannel.register(selector, SelectionKey.OP_CONNECT);

        // 6.连接服务端：
        socketChannel.connect(SERVER_ADDRESS);

        LOG.info("开启客户端...");
        // 7.打开监听
        this.listener();

    }

    /**
     * 监听器
     *
     * @throws IOException
     */
    private void listener() throws IOException {
        while (true) {

            // 1.‘选择器‘获得一组‘已被client选择的key‘：
            int size = selector.select();
            LOG.info("客户端 size：【" + size + "】");

            // 2.‘key‘处理器（事件处理器）
            this.keyProcessor(selector.selectedKeys());

        }
    }

    /**
     * key处理器（事件处理器）<br>
     * 对不同的key（事件）进行不同的处理
     *
     * @throws IOException
     */
    private void keyProcessor(Set<SelectionKey> selectedKeys) throws IOException {

        SocketChannel client = null;

        Iterator<SelectionKey> iterator = selectedKeys.iterator();
        while (iterator.hasNext()) {
            SelectionKey selectionKey = iterator.next();
            iterator.remove();

            if (selectionKey.isConnectable()) {
                this.handConnect(selectionKey, client);

            } else if (selectionKey.isReadable()) {
                this.handRead(selectionKey, client);

            } else if (selectionKey.isWritable()) {
                this.handWrit(selectionKey, client);
            }
        }
    }

    private void handConnect(SelectionKey selectionKey, SocketChannel client) throws IOException {

        client = (SocketChannel) selectionKey.channel();

        if (client.isConnectionPending()) {// 判断此通道上是否正在进行连接操作。
            if (client.finishConnect()) {// 完成套接字通道的连接过程
                LOG.info("客户端完成连接");
                sendBuf.clear(); // 缓冲区清空:
                sendBuf.put("hello world server".getBytes());
                sendBuf.flip();
                client.write(sendBuf);
            }
            // client请求读server:
            client.register(selector, SelectionKey.OP_READ);
        }
    }

    private void handRead(SelectionKey selectionKey, SocketChannel client) throws IOException {

        client = (SocketChannel) selectionKey.channel();
        receiveBuf.clear();// 1.缓冲区清空:
        int count = client.read(receiveBuf);// 2.读取服务器发送来的数据到缓冲区中

        // 3.数据处理:
        if (count > 0) {
            String receiveText = new String(receiveBuf.array(), 0, count);
            // 可以保存到数据库.....
            LOG.info("客户端接收服务端数据：receiveText：【" + receiveText + "】");

            // client注册写：
            client.register(selector, SelectionKey.OP_WRITE);
        }

    }

    private void handWrit(SelectionKey selectionKey, SocketChannel client) throws IOException {
        client = (SocketChannel) selectionKey.channel();
        // 1.将缓冲区清空
        sendBuf.clear();

        // 2.向缓冲区中输入数据
        String sendText = String.valueOf(new Date().getTime());
        sendBuf.put(sendText.getBytes());

        // 3.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
        sendBuf.flip();

        // 4.输出到通道
        client.write(sendBuf);
        LOG.info("客户端向服务器端发送数据--：" + sendText);

        // 5.client请求读server:
        client.register(selector, SelectionKey.OP_READ);
    }

    public static void main(String[] args) throws IOException {
        new NIOClient("127.0.0.1", 9999);
    }
}

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.Date;
import java.util.Iterator;
import java.util.Set;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Copyright (C),HTF<br>
 * NIO服务端<br>
 * NIO：1.缓冲区、2.选择器、3.通道、4.SelectionKey（事件类型）<br>
 * 类似于AWT事件机制
 *
 * @author muzhongjiang
 * @date 2014年8月20日
 */
public class NIOServer {

    private final Logger LOG = LoggerFactory.getLogger(this.getClass());

    private final int BLOCK = 4096;// 缓冲区大小
    private ByteBuffer sendBuf = ByteBuffer.allocate(BLOCK);// 数据接收缓冲区
    private ByteBuffer receiveBuf = ByteBuffer.allocate(BLOCK);// 数据发送缓冲区
    private Selector selector;// 通道选择器

    /**
     * 构造方法：
     */
    public NIOServer(int port) throws IOException {
        // 1.打开server端socket通道：
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();

        // 2.通道设置为非阻塞式：
        serverSocketChannel.configureBlocking(false);

        // 3.获得Socket,并绑定服务‘地址‘：
        ServerSocket serverSocket = serverSocketChannel.socket();
        serverSocket.bind(new InetSocketAddress(port));

        // 4.获得通道选择器：
        selector = Selector.open();

        /*
         * 5.在‘选择器‘上注册‘通道‘的‘事件（类型）‘<br> 一般ServerSocketChannel只注册accept事件，对于read和write事件是注册到accept的SocketChannel中的
         */
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

        LOG.info("开启服务端...");
        // 6.打开监听
        this.listener();

    }

    /**
     * 监听器
     *
     * @throws IOException
     */
    private void listener() throws IOException {

        while (true) {
            // 1.‘选择器‘获得一组‘已被client选择的key‘：
            int size = selector.select();
            LOG.info("服务端 size：【" + size + "】");
            // 2.‘key‘处理器（事件处理器）
            this.keyProcessor(selector.selectedKeys());

        }

    }

    /**
     * key处理器（事件处理器）<br>
     * 对不同的key（事件）进行不同的处理
     *
     * @throws IOException
     */
    private void keyProcessor(Set<SelectionKey> selectedKeys) throws IOException {

        SocketChannel client = null;

        Iterator<SelectionKey> iterator = selectedKeys.iterator();
        while (iterator.hasNext()) {
            SelectionKey selectionKey = iterator.next();
            iterator.remove();

            if (selectionKey.isAcceptable()) {
                this.handAccept(selectionKey, client);

            } else if (selectionKey.isReadable()) {
                this.handRead(selectionKey, client);

            } else if (selectionKey.isWritable()) {
                this.handWrit(selectionKey, client);
            }
        }
    }

    private void handAccept(SelectionKey selectionKey, SocketChannel client) throws IOException {
        LOG.info("服务端 handAccept");
        ServerSocketChannel server = (ServerSocketChannel) selectionKey.channel();

        // 1.获得client套接字通道：
        client = server.accept();

        // 2.配置为非阻塞：
        client.configureBlocking(false);

        // 3.给客户端注册read的Key：
        client.register(selector, SelectionKey.OP_READ);
    }

    private void handRead(SelectionKey selectionKey, SocketChannel client) throws IOException {

        client = (SocketChannel) selectionKey.channel();

        // 1.将缓冲区清空
        receiveBuf.clear();
        // 2.读取发送来的数据到缓冲区中
        int count = client.read(receiveBuf);
        if (count > 0) {
            String receiveText = new String(receiveBuf.array(), 0, count);
            LOG.info("服务器端接受客户端数据:" + receiveText);
            // 3.client注册write key ：
            client.register(selector, SelectionKey.OP_WRITE);
        }

    }

    private void handWrit(SelectionKey selectionKey, SocketChannel client) throws IOException {

        client = (SocketChannel) selectionKey.channel();
        // 1.将缓冲区清空
        sendBuf.clear();

        // 2.向缓冲区中输入数据
        String sendText = String.valueOf(new Date().getTime());
        sendBuf.put(sendText.getBytes());

        // 3.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
        sendBuf.flip();

        // 4.输出到通道
        client.write(sendBuf);
        LOG.info("向客户端发送数据:" + sendText);

        // 5.client注册read key ：
        client.register(selector, SelectionKey.OP_READ);
    }

    public static void main(String[] args) throws IOException {
        new NIOServer(9999);
    }
}