我最近开始使用 JBoss Netty，到目前为止我的理解是 channelPipelineFactory 用于创建 ChannelPipeline，每次服务器收到请求时。ChannelPipeline 包含一系列处理请求的 ChannelHandler。现在我的问题是，如果我的管道中的一个处理程序需要从数据库中获取数据，这就是阻塞 I/O。请求的处理被阻塞了？这与通过 Servlet 进行的常规请求处理有何不同？我对来自 NodeJS 的事件驱动异步 I/O 的理解是，有一个事件循环，并且注册了一系列用于阻塞 I/O 操作的回调函数，并且在 I/O 完成时调用这些函数。Netty 中的等价物是什么？
private static final HttpResponseEncoder httpResponseEncoder = new HttpResponseEncoder();
private static final JsonEncoder jsonEncoder = new JsonEncoder();
private static final ExecutionHandler executionHandler = new ExecutionHandler(
new OrderedMemoryAwareThreadPoolExecutor(5, 1048576, 1048576));
public static void main(String[] args) throws Exception {
ChannelFactory factory = new NioServerSocketChannelFactory(Executors.newCachedThreadPool(),
Executors.newCachedThreadPool());
SocketAddress sockAddress = new InetSocketAddress(8080);
RedisClient client = new RedisClient("127.0.0.1");
final RedisAsyncConnection<String, String> connection = client.connectAsync();
ServerBootstrap bootstrap = new ServerBootstrap(factory);
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
@Override
public ChannelPipeline getPipeline() throws Exception {
ChannelPipeline pipeline = Channels.pipeline();
pipeline.addLast("executionHandler", executionHandler);
pipeline.addLast("weightedRandomGenerator", new WeightedRandomNumberGenerator(
connection));
pipeline.addLast("encoder", httpResponseEncoder);
pipeline.addLast("JsonConverter", jsonEncoder);
return pipeline;
}
});
bootstrap.setOption("child.tcpNoDelay", true);
bootstrap.setOption("child.keepAlive", true);
bootstrap.bind(sockAddress);
}