java NIO socket programming

In java socket programming, most generally use blocking IO socket programming. Socket reading and writing will block (that is, calling the read and write methods will block regardless of whether there is currently written/read data). NIO registers I/O events and notifies you when a specific registered I/O event arrives. There is no need to poll or create a large number of threads. Here is an example: Download the

Server code

package simple.socket;  
  
import java.io.IOException;  
import java.net.InetSocketAddress;  
import java.net.ServerSocket;  
import java.nio.ByteBuffer;  
import java.nio.channels.*;  
import java.util.Iterator;  
import java.util.Set;  
  
/**  
 * Created by banxia on 16/10/12.  
 */  
public class UseNioSocket {  
  
  
    public static void main(String[] args) throws IOException {  
  
        // 创建一个selector 对象  
        Selector selector = Selector.open();  
  
        ServerSocketChannel ssc = ServerSocketChannel.open();  
        ssc.configureBlocking(false);  
        ssc.socket().bind(new InetSocketAddress(8888));  
        ssc.register(selector, SelectionKey.OP_ACCEPT);  
        ByteBuffer buffer = ByteBuffer.allocate(1024);  
  
        System.out.println("服务已经启动端口:" + 8888);  
  
        while (true) {  
  
            int selectNum = selector.select();  
            System.out.println("selectNum=" + selectNum);  
  
            if (selectNum <= 0) {  
                continue;  
            }  
            // 获取  
  
            Iterator<SelectionKey> it = selector.selectedKeys().iterator();  
  
            while (it.hasNext()) {  
  
                SelectionKey key = it.next();  
  
                if (key.readyOps() == SelectionKey.OP_ACCEPT) {  
                    // 接收 accept  
  
                    ServerSocketChannel channel = (ServerSocketChannel) key.channel();  
                    SocketChannel accept = channel.accept();  
                    accept.configureBlocking(false);  
                    System.out.println("接收客户端:" + accept.socket().getInetAddress().getHostAddress() + ":" +  accept.socket().getPort());  
                    accept.register(selector, SelectionKey.OP_READ);  
                    it.remove();  
  
  
                } else {  
  
                    SocketChannel sc = (SocketChannel) key.channel();  
                    System.out.println("接收客户端:" + sc.socket().getInetAddress().getHostAddress() + ":" + sc.socket().getPort() +"开始处理...");  
                    while (true) {  
                        buffer.clear();  
                        long l = sc.read(buffer);  
                        if (l <= 0) {  
                            break;  
                        }  
                        System.out.print(".");  
                        buffer.flip();  
                        sc.write(buffer);  
  
  
                    }  
                    System.out.print("\n");  
                    it.remove();  
                    System.out.println("接收客户端:" + sc.socket().getInetAddress().getHostAddress() + ":" + sc.socket().getPort() +"处理完成处理...");  
  
                }  
  
            }  
  
  
        }  
  
  
    }  
}