java分布式开发TCP/IP NIO无阻塞 Socket（(基于消息方式实现系统间的通信) ）
在java中可以基于java.nio.channels中的Channel和Selector的相关类来实现TCP/IP+NIO方式的系统间通信。
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用于系统间通信依靠SocketChannel和ServerSocketChannel，SocketChannel用于建立连接，监听事件及操作读写，ServerSocketChannel用于监听端口及监听连接事件，可通过Selector来获取是否有要处理的事件。
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服务端java代码：
package com.java.distributed.message.tcpip;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.net.InetSocketAddress;import java.net.SocketAddress;import java.nio.ByteBuffer;import java.nio.channels.SelectionKey;import java.nio.channels.Selector;import java.nio.channels.SocketChannel;import java.nio.charset.Charset;public class NIOClient {/** * @param args * @throws IOException */public static void main(String[] args) throws IOException {int port =7889;SocketChannel channel=SocketChannel.open();channel.configureBlocking(false);SocketAddress target=new InetSocketAddress("127.0.0.1",port);channel.connect(target);Selector selector=Selector.open();//用于套接字连接操作的操作集位channel.register(selector, SelectionKey.OP_CONNECT);BufferedReader systemIn=new BufferedReader(new InputStreamReader(System.in));while(true){if(channel.isConnected()){String command=systemIn.readLine();channel.write(Charset.forName("UTF-8").encode(command));if(command==null||"quit".equalsIgnoreCase(command.trim())){systemIn.close();channel.close();selector.close();System.out.println("Client quit !");System.exit(0);}}int nKeys=selector.select(1000);if(nKeys>0){for(SelectionKey key:selector.selectedKeys()){if(key.isConnectable()){SocketChannel sc=(SocketChannel) key.channel();sc.configureBlocking(false);sc.register(selector, SelectionKey.OP_READ);sc.finishConnect();}else if(key.isReadable()){ByteBuffer buffer=ByteBuffer.allocate(1024);SocketChannel sc=(SocketChannel) key.channel();int readBytes=0;try{int ret=0;try{while((ret=sc.read(buffer))>0){readBytes+=ret;}}finally{buffer.flip();}if (readBytes > 0) { System.out.println(Charset.forName("UTF-8") .decode(buffer).toString()); buffer = null; } }finally { if (buffer != null) { buffer.clear(); }}}}selector.selectedKeys().clear(); }}}}?
1 楼 mars914 2011-11-07 channel，Buffer，selector。Java 标准IO中基于流进行数据交互，java NIO中给出了许多Buffer，基于数据块进行操作，通过channel（通道）进行交互。Channel同时支持异步的读和写。且主要与buffer进行数据读写。