4.4 处理 read 事件

@Slf4j public class ChannelDemo6 { public static void main(String[] args) { try (ServerSocketChannel channel = ServerSocketChannel.open()) { channel.bind(new InetSocketAddress(8080)); System.out.println(channel); Selector selector = Selector.open(); channel.configureBlocking(false); channel.register(selector, SelectionKey.OP_ACCEPT);

        while (true) {
            int count = selector.select();

//                int count = selector.selectNow(); log.debug("select count: {}", count); //                if(count <= 0) { //                    continue; //                }

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            // 获取所有事件
            Set<SelectionKey> keys = selector.selectedKeys();
            // 遍历所有事件，逐一处理
            Iterator<SelectionKey> iter = keys.iterator();
            while (iter.hasNext()) {
                SelectionKey key = iter.next();
                // 判断事件类型
                if (key.isAcceptable()) {
                    ServerSocketChannel c = (ServerSocketChannel) key.channel();
                    // 必须处理
                    SocketChannel sc = c.accept();
                    sc.configureBlocking(false);
                    sc.register(selector, SelectionKey.OP_READ);
                    log.debug("连接已建立: {}", sc);
                } else if (key.isReadable()) {
                    SocketChannel sc = (SocketChannel) key.channel();
                    ByteBuffer buffer = ByteBuffer.allocate(128);
                    int read = sc.read(buffer);
                    if(read == -1) {
                        key.cancel();
                        sc.close();
                    } else {
                        buffer.flip();
                        debug(buffer);
                    }
                }
                // 处理完毕，必须将事件移除
                iter.remove();
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

} 开启两个客户端，修改一下发送文字，输出

sun.nio.ch.ServerSocketChannelImpl[/0:0:0:0:0:0:0:0:8080] 21:16:39 [DEBUG] [main] c.i.n.ChannelDemo6 - select count: 1 21:16:39 [DEBUG] [main] c.i.n.ChannelDemo6 - 连接已建立: java.nio.channels.SocketChannel[connected local=/127.0.0.1:8080 remote=/127.0.0.1:60367] 21:16:39 [DEBUG] [main] c.i.n.ChannelDemo6 - select count: 1 +-------------------------------------------------+ |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f | +--------+-------------------------------------------------+----------------+ |00000000| 68 65 6c 6c 6f                                  |hello           | +--------+-------------------------------------------------+----------------+ 21:16:59 [DEBUG] [main] c.i.n.ChannelDemo6 - select count: 1 21:16:59 [DEBUG] [main] c.i.n.ChannelDemo6 - 连接已建立: java.nio.channels.SocketChannel[connected local=/127.0.0.1:8080 remote=/127.0.0.1:60378] 21:16:59 [DEBUG] [main] c.i.n.ChannelDemo6 - select count: 1 +-------------------------------------------------+ |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f | +--------+-------------------------------------------------+----------------+ |00000000| 77 6f 72 6c 64                                  |world           | +--------+-------------------------------------------------+----------------+