【Java nio】 NonBlocking NIO

標籤：system   pac   .net   code   system.in   輪詢   java nio   監聽   out   

  1 package com.slp.nio;  2   3 import org.junit.Test;  4   5 import java.io.IOException;  6 import java.net.InetSocketAddress;  7 import java.nio.ByteBuffer;  8 import java.nio.channels.SelectionKey;  9 import java.nio.channels.Selector; 10 import java.nio.channels.ServerSocketChannel; 11 import java.nio.channels.SocketChannel; 12 import java.time.LocalDateTime; 13 import java.util.Date; 14 import java.util.Iterator; 15 import java.util.Scanner; 16  17 /** 18  * Created by sanglp on 2017/3/2. 19  * 一、使用NIO完成網路通訊的三個核心 20  * 1、通道：負責串連 21  *     |--java.nio.channels.channel介面 22  *        |--SelectableChannel 23  *           |--SocketChannel 24  *           |--ServerSocketChannel 25  *           |--DatagramChannel 26  * 27  *           |--Pipe.SinkChannel 28  *           |--Pipe.SourceChannel 29  * 2、緩衝區：負責資料的存取 30  * 3、選取器：是SelectableChannel的多工器，用於監控SelectableChannel的IO狀況 31  * 32  */ 33 public class TestNonBlockingNIO { 34  35     @Test 36     public void client() throws IOException { 37         //擷取通道 38         SocketChannel socketChannel = SocketChannel.open(new InetSocketAddress("127.0.0.1",9898)); 39         //切換為非阻塞模式 40       socketChannel.configureBlocking(false); 41         //分配緩衝區 42         ByteBuffer buf = ByteBuffer.allocate(1024); 43         //發送資料給服務端 44  45         Scanner scanner = new Scanner(System.in); 46         while (scanner.hasNext()){ 47             String str = scanner.next(); 48             buf.put((new Date().toString()+"\n"+str).getBytes()); 49             buf.flip(); 50             socketChannel.write(buf); 51             buf.clear(); 52         } 53  54  55         //關閉通道 56         socketChannel.close(); 57  58     } 59  60     @Test 61     public void server() throws IOException { 62         //擷取通道 63        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open(); 64         //切換非阻塞模式 65         serverSocketChannel.configureBlocking(false); 66         //綁定串連 67         serverSocketChannel.bind(new InetSocketAddress(9898)); 68         //擷取一個選取器 69         Selector selector = Selector.open(); 70         //將通道註冊到選取器上 並且指定監聽接收事件 71         serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT); 72         //輪詢式的擷取選取器上已經準備就緒的事件 73         while (selector.select()>0){ 74             //擷取當前選取器中所有註冊的選擇鍵(已就緒的監聽事件) 75             Iterator<SelectionKey> it = selector.selectedKeys().iterator(); 76             while (it.hasNext()){ 77                 //擷取準備就緒的事件 78                 SelectionKey sk = it.next(); 79                 //判斷具體是什麼事件準備就緒 80                 if(sk.isAcceptable()){ 81                     //擷取額護短串連 82                     SocketChannel socketChannel = serverSocketChannel.accept(); 83                     //切換非阻塞模式 84                     socketChannel.configureBlocking(false); 85                     //將該通道註冊到選取器上 86                     socketChannel.register(selector,SelectionKey.OP_READ); 87                 }else if(sk.isReadable()){ 88                     //擷取當前選取器上讀就緒狀態的通道 89                     SocketChannel socketChannel = (SocketChannel) sk.channel(); 90                     //讀取資料 91                     ByteBuffer buffer = ByteBuffer.allocate(1024); 92                     int len =0; 93                     while ((len=socketChannel.read(buffer))>0){ 94                         buffer.flip(); 95                         System.out.println(new String(buffer.array(),0,len)); 96                         buffer.clear(); 97                     } 98                 } 99                 //取消選擇鍵100                 it.remove();101             }102         }103     }104 }

 

【Java nio】 NonBlocking NIO