JAVA網絡編程-NIO之SocketChannel代碼實例

廢話很少說，直接上代碼。

服務端

package net.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.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Iterator;

/**
 *  @Description:
 *  @author:xuyaqi 
 *  @date:2018年6月6日
 */
public class Server {
    private static final int BUF_SIZE = 1024;
    private static final int PORT = 1234;
    
    private ServerSocketChannel servSocketChannel = null;
    private Selector selector = null;
    
    public static void main(String[] args) {
        new Server().startServer();
        
    }
    
    public void startServer() {
        try {  
            servSocketChannel = ServerSocketChannel.open(); 
            // 設置爲非阻塞
            servSocketChannel.configureBlocking(false);  
            // 綁定端口  
            servSocketChannel.socket().bind(new InetSocketAddress(PORT));  
            selector = Selector.open();
            // 註冊監聽事件
            servSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
            
            listen();
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }
    
    private void listen() {
        while (true) {
            try {
                // 
                selector.select();
                Iterator<SelectionKey> iter = selector.selectedKeys().iterator();
                
                while (iter.hasNext()) {
                    SelectionKey key = iter.next();
                    if (key.isValid() && key.isAcceptable()) {
                        System.out.println("handleAccept");
                        handleAccept(key);
                    }
                    if (key.isValid() && key.isReadable()) {
                        System.out.println("handleRead");
                        handleRead(key);
                    }
                    if (key.isValid() && key.isWritable()) {
                        System.out.println("handleWrite");
                        handleWrite(key);
                    }
                    if (key.isValid() && key.isConnectable()) {
                        System.out.println("isConnectable = true");
                    }
                    iter.remove();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    
    
    public static void handleAccept(SelectionKey key) throws IOException {
        ServerSocketChannel ssChannel = (ServerSocketChannel) key.channel();
        SocketChannel sc = ssChannel.accept();
        sc.configureBlocking(false);
        sc.register(key.selector(), SelectionKey.OP_READ,ByteBuffer.allocateDirect(BUF_SIZE));
    }

    public static void handleRead(SelectionKey key) throws IOException {
        SocketChannel sc = (SocketChannel) key.channel();
        try {
            ByteBuffer buf = (ByteBuffer) key.attachment();
            
            ByteBuffer writeBuffer = ByteBuffer.allocate(1024);
            int bytesRead = sc.read(buf);
            if (bytesRead > 0) {
                buf.flip();
                byte[] bytes = new byte[bytesRead];
                buf.get(bytes, 0, bytesRead);
                String str = new String(bytes);
                System.out.println(str);
                buf.clear();
                
                writeBuffer.put(bytes);
                writeBuffer.flip();
                while (writeBuffer.hasRemaining()) {
                    sc.write(writeBuffer);
                }
                writeBuffer.compact();
                
            } else {
                System.out.println("關閉的鏈接");
                key.cancel();
                sc.close();
            }
            
        } catch (Exception e) {
            e.printStackTrace();
            key.cancel();
            sc.close();
        }
        
    }

    public static void handleWrite(SelectionKey key) throws IOException {
        ByteBuffer buf = (ByteBuffer) key.attachment();
        buf.put("客戶端返回".getBytes());
        buf.flip();
        SocketChannel sc = (SocketChannel) key.channel();
        while (buf.hasRemaining()) {
            sc.write(buf);
        }
        buf.compact();
    }

}

客戶端

/**
 * 
 */
package net.nio;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;

/**
 *  @Description:
 *  @author:xuyaqi 
 *  @date:2018年6月6日
 */
public class Client implements Runnable{
    private int i  = -1;
    public Client() {
    }
    
    public Client(int i) {
        this.i = i;
    }
    
    public static void main(String[] args) throws UnsupportedEncodingException {
        
        for (int i = 0 ; i < 1; i ++) {
            new Thread(new Client(i)).start();
            
        }
        
    }
    
    @Override
    public void run() {
        startClient(i);
    }
    
    public void startClient(int i) {
        SocketChannel socketChannel = null;
        Selector selector = null;

        ByteBuffer writeBuffer = ByteBuffer.allocate(1024);
        ByteBuffer readBuffer = ByteBuffer.allocate(1024);
        
        try {
            socketChannel = SocketChannel.open();
            socketChannel.configureBlocking(false);
            socketChannel.connect(new InetSocketAddress("127.0.0.1", 1234));
            
            selector = Selector.open();
            socketChannel.register(selector, SelectionKey.OP_CONNECT);
            
            if (socketChannel.finishConnect()) {
                
                String info = "客戶端" + i + ":" + Math.random() * 1000;
                while (true) {
                    System.out.println("-------------------------------------------------------------");
                    writeBuffer.clear();
                    writeBuffer.put(info.getBytes("utf-8"));
                    writeBuffer.flip();
                    
                    while (writeBuffer.hasRemaining()) {
                        socketChannel.write(writeBuffer);
                        
                    }
                    
                    int bytesRead = socketChannel.read(readBuffer);
                    if (bytesRead > 0) {
                        readBuffer.flip();
                        byte[] bytes = new byte[bytesRead];
                        readBuffer.get(bytes, 0, bytesRead);
                        String str = new String(bytes);
                        System.out.println(str);
                        readBuffer.clear();
                        
                    } 
                    Thread.sleep(2000);
//                    Thread.sleep(Integer.MAX_VALUE);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            try {
                if (socketChannel != null) {
                    socketChannel.close();
                    System.out.println("關閉socketChannel");
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
    }
    
    public void hook () {
        Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {  
            @Override 
            public void run() {}  
        }));  
    }


}