public class NIOClient {    static int SIZE = 2;    final static int bufferSize = 500 * 1024;    static InetSocketAddress ip = new InetSocketAddress("localhost", 12345);    static CharsetEncoder encoder = Charset.forName("GB2312").newEncoder();    static class Download implements Runnable {        protected int index;        String outfile = null;        public Download(int index) {            this.index = index;            this.outfile = "c:\\" + index + ".rmvb";        }        public void run() {            FileOutputStream fout = null;            // FileChannel fcout = null;            try {                fout = new FileOutputStream(outfile);                // fcout = fout.getChannel();            } catch (FileNotFoundException e1) {                // TODO Auto-generated catch block                e1.printStackTrace();            }            try {                long start = System.currentTimeMillis();                // 打开客户端socket管道                SocketChannel client = SocketChannel.open();                // 客户端的管道的通讯模式                client.configureBlocking(false);                // 选择器                Selector selector = Selector.open();                // 往客户端管道上注册感兴趣的连接事件                client.register(selector, SelectionKey.OP_CONNECT);                // 配置IP                client.connect(ip);                // 配置缓存大小                ByteBuffer buffer = ByteBuffer.allocate(bufferSize);                int total = 0;                FOR: for (;;) {                    // 阻塞，返回发生感兴趣事件的数量                    selector.select();                    // 相当于获得感兴趣事件的集合迭代                    Iterator
     
       iter = selector.selectedKeys()                            .iterator();                    while (iter.hasNext()) {                        SelectionKey key = iter.next();                        System.out.println("-----Thread " + index                                + "------------------" + key.readyOps());                        // 删除这个马上就要被处理的事件                        iter.remove();                        // 感兴趣的是可连接的事件                        if (key.isConnectable()) {                            // 获得该事件中的管道对象                            SocketChannel channel = (SocketChannel) key.channel();                            // 如果该管道对象已经连接好了                            if (channel.isConnectionPending())                                channel.finishConnect();                            // channel.write(encoder.encode(CharBuffer                            // .wrap("d://film//" + index + ".mp3")));                            // 往管道中写一些块信息                            channel.write(encoder.encode(CharBuffer                                    .wrap("d://film//1-hadoop-1.1.2.tar.gz")));                            // 之后为该客户端管道注册新的感兴趣的事件---读操作                            channel.register(selector, SelectionKey.OP_READ);                        } else if (key.isReadable()) {                            // 由事件获得通讯管道                            SocketChannel channel = (SocketChannel) key                                    .channel();                            // 从管道中读取数据放到缓存中                            int count = channel.read(buffer);                            System.out.println("count:" + count);                            if (count > 0) {                                // 统计读取的字节数目                                total += count;                                // 这样一来从posistion~limit这段缓存数据是有效，可利用的                                // buffer.flip();                                buffer.clear();                                // 往输出文件中去写了                                if (count < bufferSize) {                                    byte[] overByte = new byte[count];                                    for (int index = 0; index < count; index++) {                                        overByte[index] = buffer.get(index);                                    }                                    fout.write(overByte);                                    // System.out.println(":::"                                    // + new String(buffer.array()));                                } else {                                    fout.write(buffer.array());                                    // System.out.println(":::"                                    // + new String(buffer.array()));                                }                            } else {                                // 关闭客户端通道                                client.close();                                // 退出大循环                                break FOR;                            }                            // ？                            // buffer.clear();                        }                    }                }                // 计算时间                double last = (System.currentTimeMillis() - start) * 1.0 / 1000;                System.out.println("Thread " + index + " downloaded " + total                        / 1024 + "kbytes in " + last + "s.");            } catch (IOException e) {                e.printStackTrace();            }        }    }    public static void main(String[] args) throws IOException {        long startTime = System.currentTimeMillis();        // 启用线程池        ExecutorService exec = Executors.newFixedThreadPool(SIZE);        for (int index = 1; index <= SIZE; index++) {            exec.execute(new Download(index));        }        exec.shutdown();        long endTime = System.currentTimeMillis();        long timeLong = endTime - startTime;        System.out.println("下载时间：" + timeLong);    }