爱华网
public class SocketChannelSelector {public static SocketChannel createSocketChannel(StringhostName, int port)throws IOException {SocketChannel sChannel = SocketChannel.open();sChannel.configureBlocking(false);sChannel.connect(new InetSocketAddress(hostName, port));return sChannel;}// 2个连接注册的选择器关键字static SelectionKey key1;static SelectionKey key2;public static void main(String[] args) {// 1个选择器，注册2个Socket 通道Selector selector = null;try {// 创建选择器selector = Selector.open();// 创建2个通道SocketChannel sChannel1 = createSocketChannel("163.net",25);SocketChannel sChannel2 = createSocketChannel("mail.csdn.net",25);// 注册选择器，侦听所有的事件//channel注册的返回的key唯一。key1 = sChannel1.register(selector,sChannel1.validOps());key2 = sChannel2.register(selector,sChannel1.validOps());} catch (IOException e) {}// 青年人网站提示等待事件的循环while (true) {try {// 等待selector.select();} catch (IOException e) {break;}// 所有事件列表Iterator<SelectionKey> it =selector.selectedKeys().iterator();// 处理每一个事件while (it.hasNext()) {// 得到关键字SelectionKey selKey = it.next();// 删除已经处理的关键字it.remove();try {// 处理事件processSelectionKey(selKey); } catch (IOException e) { // 处理异常 selKey.cancel(); } } } } public static void processSelectionKey(SelectionKey selKey)throws IOException { ByteBuffer buf = ByteBuffer.allocateDirect(1024); // 确认连接正常 if (selKey.isValid() &&selKey.isConnectable()) { // 得到通道 SocketChannel sChannel = (SocketChannel)selKey.channel(); // 是否连接完毕？ boolean success = sChannel.finishConnect(); if (!success) { // 异常 selKey.cancel(); } } // 如果可以读取数据 if (selKey.isValid() &&selKey.isReadable()) { // 得到通道 SocketChannel sChannel = (SocketChannel)selKey.channel(); if (sChannel.read(buf) > 0) { // 转到最开始 buf.flip(); while (buf.remaining() > 0) { System.out.print((char) buf.get()); } // 也可以转化为字符串，不过需要借助第三个变量了。 // buf.get(buff, 0, numBytesRead); // System.out.println(new String(buff, 0, numBytesRead,"UTF-8")); // 复位，清空 buf.clear(); } } // 如果可以写入数据 if (selKey.isValid() &&selKey.isWritable()) { // 得到通道 SocketChannel sChannel = (SocketChannel)selKey.channel(); // 区分2个侦听器的关键字 // 我这里只写一次数据。 if (!s1 &&key1.equals(selKey)) { System.out.println("channel1 write data.."); buf.clear(); buf.put("HELO localhostn".getBytes()); buf.flip(); sChannel.write(buf); s1 = true; } else if (!s2 &&key2.equals(selKey)) { System.out.println("channel2 write data.."); buf.clear(); buf.put("HELO localhostn".getBytes()); buf.flip(); sChannel.write(buf); s2 = true; } } } // 判断已经写过数据的标志 static boolean s1 = false; static boolean s2 = false; }
