使用Java NIO提高服务端程序的性能

// ==================== Program Discription ===================== // 程序名称示例 : SocketChannelDemojava // 程序目的学习Java NIO#SocketChannel // ============================================================== import javanioByteBuffer; import javaniochannelsServerSocketChannel; import javaniochannelsSocketChannel; import javaniochannelsSelector; import javaniochannelsSelectionKey; import javaniochannelsSelectableChannel; import Socket; import ServerSocket; import InetSocketAddress; import javautilIterator; public class SocketChannelDemo { public static int PORT_NUMBER = ;//监听端口 ServerSocketChannel serverChannel; ServerSocket serverSocket ; Selector selector ; private ByteBuffer buffer = ByteBufferallocateDirect (); public static void main (String [] args) throws Exception { SocketChannelDemo server=new SocketChannelDemo(); serverinit(args); serverstartWork(); } public void init (String [] argv)throws Exception { int port = PORT_NUMBER; if (argvlength > ) { port = IntegerparseInt (argv []); } Systemoutprintln (Listening on port + port); // 分配一个ServerSocketChannel serverChannel = ServerSocketChannelopen(); // 从ServerSocketChannel里获得一个对应的Socket serverSocket = serverChannelsocket(); // 生成一个Selector selector = Selectoropen(); // 把Socket绑定到端口上 serverSocketbind (new InetSocketAddress (port)); //serverChannel为非bolck nfigureBlocking (false); // 通过Selector注册ServerSocetChannel serverChannelregister (selector SelectionKeyOP_ACCEPT); } public void startWork()throws Exception { while (true) { int n = selectorselect();//获得IO准备就绪的channel数量 if (n == ) { continue; // 没有channel准备就绪继续执行 } // 用一个iterator返回Selector的selectedkeys Iterator it = selectorselectedKeys(erator(); // 处理每一个SelectionKey while (ithasNext()) { SelectionKey key = (SelectionKey) itnext(); // 判断是否有新的连接到达 if (keyisAcceptable()) {//返回SelectionKey的ServerSocketChannel ServerSocketChannel server =(ServerSocketChannel) keychannel(); SocketChannel channel = serveraccept(); registerChannel (selector channel SelectionKeyOP_READ); doWork (channel); } // 判断是否有数据在此channel里需要读取 if (keyisReadable()) { processData (key); } //删除 selectedkeys itremove(); } } } protected void registerChannel (Selector selector SelectableChannel channel int ops) throws Exception { if (channel == null) { return; } nfigureBlocking (false); channelregister (selector ops); } //处理接收的数据 protected void processData (SelectionKey key) throws Exception { SocketChannel socketChannel = (SocketChannel) keychannel(); int count; bufferclear(); // 清空buffer // 读取所有的数据 while ((count = socketChannelread (buffer)) > ) { bufferflip(); // send the data don′t assume it goes all at once while (bufferhasRemaining()) { //如果收到回车键则在返回的字符前增加[echo]$字样 if(bufferget()==(char)) { bufferclear(); bufferput([echo]___FCKpd___quot;getBytes()); bufferflip(); } socketChannelwrite (buffer);//在Socket里写数据 } bufferclear(); // 清空buffer } if (count < ) { // count<说明已经读取完毕 socketChannelclose(); } } private void doWork (SocketChannel channel)throws Exception { bufferclear(); bufferput (HelloI am workingplease input some thingand i will echo to you![echo] ___FCKpd___quot;getBytes()); bufferflip(); channelwrite (buffer); } }