import io.netty.handler.codec.http2.Http2InboundFrameLogger; //导入依赖的package包/类
private static Http2FrameReader frameReader() {
  return new Http2InboundFrameLogger(new DefaultHttp2FrameReader(),
      FRAME_LOGGER);
}
 

import io.netty.handler.codec.http2.Http2InboundFrameLogger; //导入依赖的package包/类
private static Http2FrameReader frameReader() {
    return new Http2InboundFrameLogger(new DefaultHttp2FrameReader(), logger);
}
 

import io.netty.handler.codec.http2.Http2InboundFrameLogger; //导入依赖的package包/类
public HelloWorldHttp2Handler() {
    this(new DefaultHttp2Connection(true), new Http2InboundFrameLogger(
            new DefaultHttp2FrameReader(), logger), 
            new Http2OutboundFrameLogger(new DefaultHttp2FrameWriter(), logger), 
            new SimpleHttp2FrameListener());
}
 

import io.netty.handler.codec.http2.Http2InboundFrameLogger; //导入依赖的package包/类
private Http2FrameReader frameReader() {
    return new Http2InboundFrameLogger(new DefaultHttp2FrameReader(), logger);
}
 

import io.netty.handler.codec.http2.Http2InboundFrameLogger; //导入依赖的package包/类
static NettyServerHandler newHandler(
    ServerTransportListener transportListener,
    ChannelPromise channelUnused,
    List<ServerStreamTracer.Factory> streamTracerFactories,
    TransportTracer transportTracer,
    int maxStreams,
    int flowControlWindow,
    int maxHeaderListSize,
    int maxMessageSize,
    long keepAliveTimeInNanos,
    long keepAliveTimeoutInNanos,
    long maxConnectionIdleInNanos,
    long maxConnectionAgeInNanos,
    long maxConnectionAgeGraceInNanos,
    boolean permitKeepAliveWithoutCalls,
    long permitKeepAliveTimeInNanos) {
  Preconditions.checkArgument(maxHeaderListSize > 0, "maxHeaderListSize must be positive");
  Http2FrameLogger frameLogger = new Http2FrameLogger(LogLevel.DEBUG, NettyServerHandler.class);
  Http2HeadersDecoder headersDecoder = new GrpcHttp2ServerHeadersDecoder(maxHeaderListSize);
  Http2FrameReader frameReader = new Http2InboundFrameLogger(
      new DefaultHttp2FrameReader(headersDecoder), frameLogger);
  Http2FrameWriter frameWriter =
      new Http2OutboundFrameLogger(new DefaultHttp2FrameWriter(), frameLogger);
  return newHandler(
      channelUnused,
      frameReader,
      frameWriter,
      transportListener,
      streamTracerFactories,
      transportTracer,
      maxStreams,
      flowControlWindow,
      maxHeaderListSize,
      maxMessageSize,
      keepAliveTimeInNanos,
      keepAliveTimeoutInNanos,
      maxConnectionIdleInNanos,
      maxConnectionAgeInNanos,
      maxConnectionAgeGraceInNanos,
      permitKeepAliveWithoutCalls,
      permitKeepAliveTimeInNanos);
}