170407、java基于nio工作方式的socket通信

客户端代码：

/**
 *
 */
package com.bobohe.nio;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
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.nio.charset.Charset;

/**
 * 实现TCP/IP+NIO 方式的系统间通讯的代码，客户端：
 *
 * @author solo
 */
public class NioClient {

    /**
     * create solo
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        String host = "127.0.0.1";
        int port = 9527;

        Selector selector = Selector.open();

        SocketChannel clientChannel = SocketChannel.open();
        clientChannel.configureBlocking(false);
        clientChannel.connect(new InetSocketAddress(host, port));

        clientChannel.register(selector, SelectionKey.OP_CONNECT);

        BufferedReader systemIn = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            if (clientChannel.isConnected()) {
                String command = systemIn.readLine();
                clientChannel.write(Charset.forName("UTF-8").encode(command));

                if (command == null || "quit".equalsIgnoreCase(command)) {
                    System.out.println("Client quit!");

                    systemIn.close();
                    clientChannel.close();
                    selector.close();
                    System.exit(0);
                }

            }

            //最长阻塞10s
            int nKeys = selector.select(10 * 1000);
            if (nKeys > 0) {
                for (SelectionKey selectionKey : selector.selectedKeys()) {
                    if (selectionKey.isConnectable()) {
                        SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
                        socketChannel.configureBlocking(false);
                        socketChannel.register(selector, SelectionKey.OP_READ);
                        socketChannel.finishConnect();
                    } else if (selectionKey.isReadable()) {
                        SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
                        StringBuilder sb = new StringBuilder();

                        ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
                        try {
                            int readBytes = 0;
                            int ret = 0;
                            while ((ret = socketChannel.read(byteBuffer)) > 0) {
                                readBytes += ret;
                                byteBuffer.flip();

                                sb.append(Charset.forName("UTF-8").decode(byteBuffer).toString());

                                byteBuffer.clear();
                            }

                            if (readBytes == 0) {
                                /*
                                 * handle Exception
                                 */
                                System.err.println("handle opposite close Exception");
                                socketChannel.close();
                            }
                        } catch (IOException e) {
                            /*
                             * handle Exception
                             */
                            System.err.println("handle read Exception");
                            socketChannel.close();
                        } finally {
                            byteBuffer.clear();
                        }

                        String message = sb.toString();
                        System.out.println(message);
                    }
                }
                selector.selectedKeys().clear();

            } else {
                /*
                 * handle Exception
                 * 三秒没有响应则打印错误信息
                 */
                System.err.println("handle select timeout Exception");
                clientChannel.close();
            }

        }
    }

}

服务端代码：

/**
 *
 */

package com.bobohe.nio;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
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.nio.charset.Charset;

/**
 * 实现TCP/IP+NIO 方式的系统间通讯的代码，服务器端： SocketChannel和ServerSocketChannel两个关键的类，网络IO
 * 的操作则改为通过ByteBuffer来实现。
 *
 * @author solo
 */
public class NioServer {

    /**
     * create by solo
     *
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        int port = 9527;
        System.out.println("Server listen on port: " + port);

        Selector selector = Selector.open();

        ServerSocketChannel serverChannel = ServerSocketChannel.open();
        ServerSocket serverSocket = serverChannel.socket();
        serverSocket.bind(new InetSocketAddress(port));
        serverChannel.configureBlocking(false);

        serverChannel.register(selector, SelectionKey.OP_ACCEPT);
        while (true) {
            int nKeys = selector.select();
            if (nKeys > 0) {
                for (SelectionKey selectionKey : selector.selectedKeys()) {
                    if (selectionKey.isAcceptable()) {
                        ServerSocketChannel tempServerChannel = (ServerSocketChannel) selectionKey
                                .channel();
                        SocketChannel socketChannel = tempServerChannel
                                .accept();
                        if (socketChannel == null) {
                            continue;
                        }

                        socketChannel.configureBlocking(false);
                        socketChannel.register(selector, SelectionKey.OP_READ);
                    } else if (selectionKey.isReadable()) {
                        // try { Thread.sleep(5000); } catch
                        // (InterruptedException e) { e.printStackTrace(); }
                        SocketChannel socketChannel = (SocketChannel) selectionKey
                                .channel();

                        StringBuilder sb = new StringBuilder();
                        ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
                        try {
                            int readBytes = 0;
                            int ret = 0;
                            while ((ret = socketChannel.read(byteBuffer)) > 0) {
                                readBytes += ret;
                                byteBuffer.flip();

                                sb.append(Charset.forName("UTF-8")
                                        .decode(byteBuffer).toString());

                                byteBuffer.clear();
                            }

                            if (readBytes == 0) {
                                /*
                                 * handle Exception
                                 */
                                System.err
                                        .println("handle opposite close Exception");
                                socketChannel.close();
                            }

                            String message = sb.toString();
                            System.out.println("client: "
                                    + message);
                            if ("quit".equalsIgnoreCase(message.toString()
                                    .trim())) {
                                System.out.println("Client has been quit!");

                                socketChannel.close();
                            } else if ("serverquit".equalsIgnoreCase(message
                                    .trim())) {
                                System.out.println("Server has been shutdown!");

                                socketChannel.close();
                                serverChannel.close();
                                selector.close();
                                System.exit(0);
                            } else {
                                socketChannel.write(Charset.forName("UTF-8").encode("Server Handler Done!"));
                            }
                        } catch (IOException e) {
                            /*
                             * handle Exception
                             */
                            System.err.println("handle read Exception");
                            socketChannel.close();
                        } finally {
                            byteBuffer.clear();
                        }

                    }
                }
                selector.selectedKeys().clear();

            }
        }
    }

}