1 /*
2 * Copyright 2020 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License, version 2.0 (the
5 * "License"); you may not use this file except in compliance with the License. You may obtain a
6 * copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software distributed under the License
11 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
12 * or implied. See the License for the specific language governing permissions and limitations under
13 * the License.
14 */
15 package io.netty.example.http2.helloworld.frame.client;
16
17 import io.netty.channel.ChannelHandlerContext;
18 import io.netty.channel.SimpleChannelInboundHandler;
19 import io.netty.handler.codec.http2.Http2DataFrame;
20 import io.netty.handler.codec.http2.Http2HeadersFrame;
21 import io.netty.handler.codec.http2.Http2StreamFrame;
22
23 import java.util.concurrent.CountDownLatch;
24 import java.util.concurrent.TimeUnit;
25
26 /**
27 * Handles HTTP/2 stream frame responses. This is a useful approach if you specifically want to check
28 * the main HTTP/2 response DATA/HEADERs, but in this example it's used purely to see whether
29 * our request (for a specific stream id) has had a final response (for that same stream id).
30 */
31 public final class Http2ClientStreamFrameResponseHandler extends SimpleChannelInboundHandler<Http2StreamFrame> {
32
33 private final CountDownLatch latch = new CountDownLatch(1);
34
35 @Override
36 protected void channelRead0(ChannelHandlerContext ctx, Http2StreamFrame msg) throws Exception {
37 System.out.println("Received HTTP/2 'stream' frame: " + msg);
38
39 // isEndStream() is not from a common interface, so we currently must check both
40 if (msg instanceof Http2DataFrame && ((Http2DataFrame) msg).isEndStream()) {
41 latch.countDown();
42 } else if (msg instanceof Http2HeadersFrame && ((Http2HeadersFrame) msg).isEndStream()) {
43 latch.countDown();
44 }
45 }
46
47 /**
48 * Waits for the latch to be decremented (i.e. for an end of stream message to be received), or for
49 * the latch to expire after 5 seconds.
50 * @return true if a successful HTTP/2 end of stream message was received.
51 */
52 public boolean responseSuccessfullyCompleted() {
53 try {
54 return latch.await(5, TimeUnit.SECONDS);
55 } catch (InterruptedException ie) {
56 System.err.println("Latch exception: " + ie.getMessage());
57 return false;
58 }
59 }
60
61 }