package cn.bridgeli.demo;
 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
 
/**
 * @author bridgeli
 */
public class SocketBIO {
 
 
    public static void main(String[] args) throws Exception {
        ServerSocket server = new ServerSocket(9090, 20);
 
        System.out.println("step1: new ServerSocket(9090) ");
 
        while (true) {
            Socket client = server.accept();
            System.out.println("step2:client: " + client.getPort());
 
            new Thread(new Runnable() {
                @Override
                public void run() {
                    InputStream inputStream = null;
                    BufferedReader reader = null;
                    try {
                        inputStream = client.getInputStream();
                        reader = new BufferedReader(new InputStreamReader(inputStream));
                        while (true) {
                            String dataLine = reader.readLine(); //阻塞2
                            if (null != dataLine) {
                                System.out.println(dataLine);
                            } else {
                                client.close();
                                break;
                            }
                        }
                        System.out.println("客戶端斷開");
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        if (null != reader) {
                            try {
                                reader.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                        if (null!= inputStream) {
                            try {
                                inputStream.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                    }
 
                }
 
 
            }).start();
 
        }
    }
 
}

package cn.bridgeli.demo;
 
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.LinkedList;
 
/**
 * @author bridgeli
 */
public class SocketNIO {
 
    public static void main(String[] args) throws Exception {
 
        LinkedList<SocketChannel> clients = new LinkedList<>();
 
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.bind(new InetSocketAddress(9090));
        serverSocketChannel.configureBlocking(false);
 
        while (true) {
            SocketChannel client = serverSocketChannel.accept();
 
            if (null != client) {
                client.configureBlocking(false);
                System.out.println("client port: " + client.socket().getPort());
                clients.add(client);
            }
 
            ByteBuffer buffer = ByteBuffer.allocateDirect(4096);
 
            for (SocketChannel c : clients) {
                int num = c.read(buffer);
                if (num > 0) {
                    buffer.flip();
                    byte[] aaa = new byte[buffer.limit()];
                    buffer.get(aaa);
 
                    String b = new String(aaa);
                    System.out.println(c.socket().getPort() + " : " + b);
                    buffer.clear();
                }
            }
        }
    }
 
}

package cn.bridgeli.demo;
 
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.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;
 
/**
 * @author bridgeli
 */
public class SocketMultiplexingIO {
 
    private ServerSocketChannel serverSocketChannel = null;
    private Selector selector = null;
 
    public void initServer() {
        try {
            serverSocketChannel = ServerSocketChannel.open();
            serverSocketChannel.configureBlocking(false);
            serverSocketChannel.bind(new InetSocketAddress(9090));
            selector = Selector.open();
            serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    public void start() {
        initServer();
        System.out.println("服務(wù)器啟動(dòng)了...");
        try {
            while (true) {
 
                while (selector.select() > 0) {
                    Set<SelectionKey> selectionKeys = selector.selectedKeys();
                    Iterator<SelectionKey> iterator = selectionKeys.iterator();
                    while (iterator.hasNext()) {
                        SelectionKey key = iterator.next();
                        iterator.remove();
                        if (key.isAcceptable()) {
                            acceptHandler(key);
                        } else if (key.isReadable()) {
                            readHandler(key);
                        }
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    public void acceptHandler(SelectionKey key) {
        try {
            ServerSocketChannel ssc = (ServerSocketChannel) key.channel();
            SocketChannel client = ssc.accept();
            client.configureBlocking(false);
 
            ByteBuffer buffer = ByteBuffer.allocate(8192);
 
            client.register(selector, SelectionKey.OP_READ, buffer);
            System.out.println("新客戶端：" + client.getRemoteAddress());
 
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    public void readHandler(SelectionKey key) {
        SocketChannel client = (SocketChannel) key.channel();
        ByteBuffer buffer = (ByteBuffer) key.attachment();
        buffer.clear();
        int read = 0;
        try {
            while (true) {
                read = client.read(buffer);
                if (read > 0) {
                    buffer.flip();
                    while (buffer.hasRemaining()) {
                        client.write(buffer);
                    }
                    buffer.clear();
                } else if (read == 0) {
                    break;
                } else {
                    client.close();
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
 
        }
    }
 
    public static void main(String[] args) {
        SocketMultiplexingIO service = new SocketMultiplexingIO();
        service.start();
    }
}

strace -ff -o out + 要追蹤的進(jìn)程