Java tutorial
/* * 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 com.hop.hhxx.example.http2.helloworld.client; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelPromise; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.codec.http.FullHttpResponse; import io.netty.handler.codec.http2.HttpConversionUtil; import io.netty.util.CharsetUtil; import java.util.AbstractMap.SimpleEntry; import java.util.Iterator; import java.util.Map.Entry; import java.util.SortedMap; import java.util.TreeMap; import java.util.concurrent.TimeUnit; /** * Process {@link FullHttpResponse} translated from HTTP/2 frames */ public class HttpResponseHandler extends SimpleChannelInboundHandler<FullHttpResponse> { private SortedMap<Integer, Entry<ChannelFuture, ChannelPromise>> streamidPromiseMap; public HttpResponseHandler() { streamidPromiseMap = new TreeMap<Integer, Entry<ChannelFuture, ChannelPromise>>(); } /** * Create an association between an anticipated response stream id and a {@link ChannelPromise} * * @param streamId The stream for which a response is expected * @param writeFuture A future that represent the request write operation * @param promise The promise object that will be used to wait/notify events * @return The previous object associated with {@code streamId} * @see HttpResponseHandler#awaitResponses(long, TimeUnit) */ public Entry<ChannelFuture, ChannelPromise> put(int streamId, ChannelFuture writeFuture, ChannelPromise promise) { return streamidPromiseMap.put(streamId, new SimpleEntry<ChannelFuture, ChannelPromise>(writeFuture, promise)); } /** * Wait (sequentially) for a time duration for each anticipated response * * @param timeout Value of time to wait for each response * @param unit Units associated with {@code timeout} * @see HttpResponseHandler#put(int, ChannelFuture, ChannelPromise) */ public void awaitResponses(long timeout, TimeUnit unit) { Iterator<Entry<Integer, Entry<ChannelFuture, ChannelPromise>>> itr = streamidPromiseMap.entrySet() .iterator(); while (itr.hasNext()) { Entry<Integer, Entry<ChannelFuture, ChannelPromise>> entry = itr.next(); ChannelFuture writeFuture = entry.getValue().getKey(); if (!writeFuture.awaitUninterruptibly(timeout, unit)) { throw new IllegalStateException("Timed out waiting to write for stream id " + entry.getKey()); } if (!writeFuture.isSuccess()) { throw new RuntimeException(writeFuture.cause()); } ChannelPromise promise = entry.getValue().getValue(); if (!promise.awaitUninterruptibly(timeout, unit)) { throw new IllegalStateException("Timed out waiting for response on stream id " + entry.getKey()); } if (!promise.isSuccess()) { throw new RuntimeException(promise.cause()); } System.out.println("---Stream id: " + entry.getKey() + " received---"); itr.remove(); } } @Override protected void channelRead0(ChannelHandlerContext ctx, FullHttpResponse msg) throws Exception { Integer streamId = msg.headers().getInt(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text()); if (streamId == null) { System.err.println("HttpResponseHandler unexpected message received: " + msg); return; } Entry<ChannelFuture, ChannelPromise> entry = streamidPromiseMap.get(streamId); if (entry == null) { System.err.println("Message received for unknown stream id " + streamId); } else { // Do stuff with the message (for now just print it) ByteBuf content = msg.content(); if (content.isReadable()) { int contentLength = content.readableBytes(); byte[] arr = new byte[contentLength]; content.readBytes(arr); System.out.println(new String(arr, 0, contentLength, CharsetUtil.UTF_8)); } entry.getValue().setSuccess(); } } }