781a85520c
Motivation: Adding an example that showcases Netty’s HTTP/2 codec and that is slightly more complex than the existing hello-world example. It is based on the Gopher tiles example available here: https://http2.golang.org/gophertiles?latency=0 Modifications: Moved current http2 example to http2/helloworld. Added http2 tiles example under http2/tiles. Result: A Netty tiles example is available.
135 lines
5.8 KiB
Java
135 lines
5.8 KiB
Java
/*
|
|
* Copyright 2014 The Netty Project
|
|
*
|
|
* The Netty Project licenses this file to you under the Apache License, version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the License. You may obtain a
|
|
* copy of the License at:
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software distributed under the License
|
|
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
|
|
* or implied. See the License for the specific language governing permissions and limitations under
|
|
* the License.
|
|
*/
|
|
|
|
package io.netty.example.http2.helloworld.server;
|
|
|
|
import static io.netty.buffer.Unpooled.copiedBuffer;
|
|
import static io.netty.buffer.Unpooled.unreleasableBuffer;
|
|
import static io.netty.example.http2.Http2ExampleUtil.UPGRADE_RESPONSE_HEADER;
|
|
import static io.netty.handler.codec.http.HttpResponseStatus.OK;
|
|
import static io.netty.handler.logging.LogLevel.INFO;
|
|
import io.netty.buffer.ByteBuf;
|
|
import io.netty.buffer.ByteBufUtil;
|
|
import io.netty.channel.ChannelHandlerContext;
|
|
import io.netty.handler.codec.http.HttpServerUpgradeHandler;
|
|
import io.netty.handler.codec.http2.DefaultHttp2Connection;
|
|
import io.netty.handler.codec.http2.DefaultHttp2FrameReader;
|
|
import io.netty.handler.codec.http2.DefaultHttp2FrameWriter;
|
|
import io.netty.handler.codec.http2.DefaultHttp2Headers;
|
|
import io.netty.handler.codec.http2.Http2Connection;
|
|
import io.netty.handler.codec.http2.Http2ConnectionEncoder;
|
|
import io.netty.handler.codec.http2.Http2ConnectionHandler;
|
|
import io.netty.handler.codec.http2.Http2Exception;
|
|
import io.netty.handler.codec.http2.Http2FrameAdapter;
|
|
import io.netty.handler.codec.http2.Http2FrameLogger;
|
|
import io.netty.handler.codec.http2.Http2FrameReader;
|
|
import io.netty.handler.codec.http2.Http2FrameWriter;
|
|
import io.netty.handler.codec.http2.Http2Headers;
|
|
import io.netty.handler.codec.http2.Http2InboundFrameLogger;
|
|
import io.netty.handler.codec.http2.Http2OutboundFrameLogger;
|
|
import io.netty.util.AsciiString;
|
|
import io.netty.util.CharsetUtil;
|
|
|
|
/**
|
|
* A simple handler that responds with the message "Hello World!".
|
|
*/
|
|
public class HelloWorldHttp2Handler extends Http2ConnectionHandler {
|
|
|
|
private static final Http2FrameLogger logger = new Http2FrameLogger(INFO, HelloWorldHttp2Handler.class);
|
|
static final ByteBuf RESPONSE_BYTES = unreleasableBuffer(copiedBuffer("Hello World", CharsetUtil.UTF_8));
|
|
|
|
public HelloWorldHttp2Handler() {
|
|
this(new DefaultHttp2Connection(true), new Http2InboundFrameLogger(
|
|
new DefaultHttp2FrameReader(), logger), new Http2OutboundFrameLogger(
|
|
new DefaultHttp2FrameWriter(), logger), new SimpleHttp2FrameListener());
|
|
}
|
|
|
|
private HelloWorldHttp2Handler(Http2Connection connection, Http2FrameReader frameReader,
|
|
Http2FrameWriter frameWriter, SimpleHttp2FrameListener listener) {
|
|
super(connection, frameReader, frameWriter, listener);
|
|
listener.encoder(encoder());
|
|
}
|
|
|
|
/**
|
|
* Handles the cleartext HTTP upgrade event. If an upgrade occurred, sends a simple response via HTTP/2
|
|
* on stream 1 (the stream specifically reserved for cleartext HTTP upgrade).
|
|
*/
|
|
@Override
|
|
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
|
|
if (evt instanceof HttpServerUpgradeHandler.UpgradeEvent) {
|
|
// Write an HTTP/2 response to the upgrade request
|
|
Http2Headers headers =
|
|
new DefaultHttp2Headers().status(OK.codeAsText())
|
|
.set(new AsciiString(UPGRADE_RESPONSE_HEADER), new AsciiString("true"));
|
|
encoder().writeHeaders(ctx, 1, headers, 0, true, ctx.newPromise());
|
|
}
|
|
super.userEventTriggered(ctx, evt);
|
|
}
|
|
|
|
@Override
|
|
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
|
|
super.exceptionCaught(ctx, cause);
|
|
cause.printStackTrace();
|
|
ctx.close();
|
|
}
|
|
|
|
private static class SimpleHttp2FrameListener extends Http2FrameAdapter {
|
|
private Http2ConnectionEncoder encoder;
|
|
|
|
public void encoder(Http2ConnectionEncoder encoder) {
|
|
this.encoder = encoder;
|
|
}
|
|
|
|
/**
|
|
* If receive a frame with end-of-stream set, send a pre-canned response.
|
|
*/
|
|
@Override
|
|
public int onDataRead(ChannelHandlerContext ctx, int streamId, ByteBuf data, int padding,
|
|
boolean endOfStream) throws Http2Exception {
|
|
int processed = data.readableBytes() + padding;
|
|
if (endOfStream) {
|
|
sendResponse(ctx, streamId, data.retain());
|
|
}
|
|
return processed;
|
|
}
|
|
|
|
/**
|
|
* If receive a frame with end-of-stream set, send a pre-canned response.
|
|
*/
|
|
@Override
|
|
public void onHeadersRead(ChannelHandlerContext ctx, int streamId,
|
|
Http2Headers headers, int streamDependency, short weight,
|
|
boolean exclusive, int padding, boolean endStream) throws Http2Exception {
|
|
if (endStream) {
|
|
ByteBuf content = ctx.alloc().buffer();
|
|
content.writeBytes(HelloWorldHttp2Handler.RESPONSE_BYTES.duplicate());
|
|
ByteBufUtil.writeAscii(content, " - via HTTP/2");
|
|
sendResponse(ctx, streamId, content);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Sends a "Hello World" DATA frame to the client.
|
|
*/
|
|
private void sendResponse(ChannelHandlerContext ctx, int streamId, ByteBuf payload) {
|
|
// Send a frame for the response status
|
|
Http2Headers headers = new DefaultHttp2Headers().status(OK.codeAsText());
|
|
encoder.writeHeaders(ctx, streamId, headers, 0, false, ctx.newPromise());
|
|
encoder.writeData(ctx, streamId, payload, 0, true, ctx.newPromise());
|
|
ctx.flush();
|
|
}
|
|
}
|
|
}
|