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本文主要研究一下 reactor-netty 的 AccessLogHandlerH2
AccessLogHandlerH2
reactor-netty-0.8.5.RELEASE-sources.jar!/reactor/netty/http/server/AccessLogHandlerH2.java
final class AccessLogHandlerH2 extends ChannelDuplexHandler {
static final String H2_PROTOCOL_NAME = “HTTP/2.0”;
AccessLog accessLog = new AccessLog();
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof Http2HeadersFrame){
final Http2HeadersFrame requestHeaders = (Http2HeadersFrame) msg;
final SocketChannel channel = (SocketChannel) ctx.channel()
.parent();
final Http2Headers headers = requestHeaders.headers();
accessLog = new AccessLog()
.address(channel.remoteAddress().getHostString())
.port(channel.localAddress().getPort())
.method(headers.method())
.uri(headers.path())
.protocol(H2_PROTOCOL_NAME);
}
super.channelRead(ctx, msg);
}
@Override
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
boolean lastContent = false;
if (msg instanceof Http2HeadersFrame) {
final Http2HeadersFrame responseHeaders = (Http2HeadersFrame) msg;
final Http2Headers headers = responseHeaders.headers();
lastContent = responseHeaders.isEndStream();
accessLog.status(headers.status())
.chunked(true);
}
if (msg instanceof Http2DataFrame) {
final Http2DataFrame data = (Http2DataFrame) msg;
lastContent = data.isEndStream();
accessLog.increaseContentLength(data.content().readableBytes());
}
if (lastContent) {
ctx.write(msg, promise)
.addListener(future -> {
if (future.isSuccess()) {
accessLog.log();
}
});
return;
}
ctx.write(msg, promise);
}
}
AccessLogHandlerH2 是 HTTP2 的 access log 的实现，具体针对 Http2HeadersFrame 及 Http2DataFrame 进行了判断
HttpServerBind
reactor-netty-0.8.5.RELEASE-sources.jar!/reactor/netty/http/server/HttpServerBind.java
final class HttpServerBind extends HttpServer
implements Function<ServerBootstrap, ServerBootstrap> {
//……
static void addStreamHandlers(Channel ch, ConnectionObserver listener, boolean readForwardHeaders,
ServerCookieEncoder encoder, ServerCookieDecoder decoder) {
if (ACCESS_LOG) {
ch.pipeline()
.addLast(NettyPipeline.AccessLogHandler, new AccessLogHandlerH2());
}
ch.pipeline()
.addLast(new Http2StreamBridgeHandler(listener, readForwardHeaders, encoder, decoder))
.addLast(new Http2StreamFrameToHttpObjectCodec(true));
ChannelOperations.addReactiveBridge(ch, ChannelOperations.OnSetup.empty(), listener);
if (log.isDebugEnabled()) {
log.debug(format(ch, “Initialized HTTP/2 pipeline {}”), ch.pipeline());
}
}
//……
HttpServerBind 的 addStreamHandlers 静态方法用于判断是否开启 access log，开启的话会创建 AccessLogHandlerH2 并添加到 pipeline；Http1OrH2CleartextCodec 的 initChannel 方法以及 Http2StreamInitializer 的 initChannel 方法均调用到了此方法
小结
AccessLogHandlerH2 是 HTTP2 的 access log 的实现，具体针对 Http2HeadersFrame 及 Http2DataFrame 进行了判断
HttpServerBind 的 addStreamHandlers 静态方法用于判断是否开启 access log，开启的话会创建 AccessLogHandlerH2 并添加到 pipeline
Http1OrH2CleartextCodec 的 initChannel 方法以及 Http2StreamInitializer 的 initChannel 方法均调用到了此方法
doc
Spring Boot Reactor Netty Configuration
