我正在实施一个位于公司代理后面的 Netty 客户端（实际上，我正在尝试自定义 Camel 的 netty-http 组件以使用 http 代理）。
当我直接使用我的客户端配置时，没有 HttpProxyHandler（在公司网络外的机器上），它可以工作。但是当我在公司网络内的一台机器上运行代码时，我得到这个错误消息（目标主机匿名）：
java.net.ConnectException: Cannot connect to myserver.example.de:443
at org.apache.camel.component.netty.NettyProducer$ChannelConnectedListener.operationComplete(NettyProducer.java:699)
at org.apache.camel.component.netty.NettyProducer$ChannelConnectedListener.operationComplete(NettyProducer.java:685)
at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:590)
at io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:583)
at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:559)
at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:492)
at io.netty.util.concurrent.DefaultPromise.setValue0(DefaultPromise.java:636)
at io.netty.util.concurrent.DefaultPromise.setFailure0(DefaultPromise.java:629)
at io.netty.util.concurrent.DefaultPromise.setFailure(DefaultPromise.java:110)
at io.netty.channel.DefaultChannelPromise.setFailure(DefaultChannelPromise.java:89)
at io.netty.bootstrap.Bootstrap.doResolveAndConnect0(Bootstrap.java:214)
at io.netty.bootstrap.Bootstrap.access$000(Bootstrap.java:46)
at io.netty.bootstrap.Bootstrap$1.operationComplete(Bootstrap.java:180)
at io.netty.bootstrap.Bootstrap$1.operationComplete(Bootstrap.java:166)
at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:590)
at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:557)
at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:492)
at io.netty.util.concurrent.DefaultPromise.setValue0(DefaultPromise.java:636)
at io.netty.util.concurrent.DefaultPromise.setSuccess0(DefaultPromise.java:625)
at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:105)
at io.netty.channel.DefaultChannelPromise.trySuccess(DefaultChannelPromise.java:84)
at io.netty.channel.AbstractChannel$AbstractUnsafe.safeSetSuccess(AbstractChannel.java:990)
at io.netty.channel.AbstractChannel$AbstractUnsafe.register0(AbstractChannel.java:516)
at io.netty.channel.AbstractChannel$AbstractUnsafe.access$200(AbstractChannel.java:429)
at io.netty.channel.AbstractChannel$AbstractUnsafe$1.run(AbstractChannel.java:486)
at io.netty.util.concurrent.AbstractEventExecutor.runTask$$$capture(AbstractEventExecutor.java:174)
at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute$$$capture(AbstractEventExecutor.java:167)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:569)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.net.UnknownHostException: myserver.example.de
at java.base/java.net.InetAddress$CachedAddresses.get(InetAddress.java:797)
at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1533)
at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1386)
at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1307)
at java.base/java.net.InetAddress.getByName(InetAddress.java:1257)
at io.netty.util.internal.SocketUtils$8.run(SocketUtils.java:156)
at io.netty.util.internal.SocketUtils$8.run(SocketUtils.java:153)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at io.netty.util.internal.SocketUtils.addressByName(SocketUtils.java:153)
at io.netty.resolver.DefaultNameResolver.doResolve(DefaultNameResolver.java:41)
at io.netty.resolver.SimpleNameResolver.resolve(SimpleNameResolver.java:61)
at io.netty.resolver.SimpleNameResolver.resolve(SimpleNameResolver.java:53)
at io.netty.resolver.InetSocketAddressResolver.doResolve(InetSocketAddressResolver.java:55)
at io.netty.resolver.InetSocketAddressResolver.doResolve(InetSocketAddressResolver.java:31)
at io.netty.resolver.AbstractAddressResolver.resolve(AbstractAddressResolver.java:106)
at io.netty.bootstrap.Bootstrap.doResolveAndConnect0(Bootstrap.java:206)
... 23 more
这就是我初始化客户端的方式。请注意紧接在 SSLHandler 之后的 HttpProxyHandler，这是我为获得对公司代理的支持所做的。
@Override
protected void initChannel(Channel ch) throws Exception {
// create a new pipeline
ChannelPipeline pipeline = ch.pipeline();
SslHandler sslHandler = configureClientSSLOnDemand();
if (sslHandler != null) {
LOG.debug("Client SSL handler configured and added as an interceptor against the ChannelPipeline: {}", sslHandler);
pipeline.addLast("ssl", sslHandler);
}
HttpProxyHandler httpProxyHandler = new HttpProxyHandler(
new InetSocketAddress("myproxy.corporate.de", 3128));
pipeline.addLast("httpproxy", httpProxyHandler);
pipeline.addLast("http", new HttpClientCodec());
List<ChannelHandler> encoders = producer.getConfiguration()
.getEncodersAsList();
for (int x = 0; x < encoders.size(); x++) {
ChannelHandler encoder = encoders.get(x);
if (encoder instanceof ChannelHandlerFactory) {
// use the factory to create a new instance of the channel as it may not be shareable
encoder = ((ChannelHandlerFactory) encoder).newChannelHandler();
}
pipeline.addLast("encoder-" + x, encoder);
}
List<ChannelHandler> decoders = producer.getConfiguration()
.getDecodersAsList();
for (int x = 0; x < decoders.size(); x++) {
ChannelHandler decoder = decoders.get(x);
if (decoder instanceof ChannelHandlerFactory) {
// use the factory to create a new instance of the channel as it may not be shareable
decoder = ((ChannelHandlerFactory) decoder).newChannelHandler();
}
pipeline.addLast("decoder-" + x, decoder);
}
if (configuration.isDisableStreamCache()) {
pipeline.addLast("inbound-streamer", new HttpInboundStreamHandler());
}
pipeline.addLast("aggregator", new HttpObjectAggregator(configuration.getChunkedMaxContentLength()));
pipeline.addLast("outbound-streamer", new HttpOutboundStreamHandler());
if (producer.getConfiguration()
.getRequestTimeout() > 0) {
if (LOG.isTraceEnabled()) {
LOG.trace("Using request timeout {} millis", producer.getConfiguration()
.getRequestTimeout());
}
ChannelHandler timeout
= new ReadTimeoutHandler(producer.getConfiguration()
.getRequestTimeout(), TimeUnit.MILLISECONDS);
pipeline.addLast("timeout", timeout);
}
// handler to route Camel messages
pipeline.addLast("handler", new HttpClientChannelHandler(producer));
}
ProxyHandler.handlerAdded 被调用，它又调用 HttpProxyHandler.addCodec。在那里，http 代理处理程序使用 addBefore("httpproxy", null, codecWrapper) 添加其内部类 HttpClientCodecWrapper。 HttpClientCodecWrapper 接收其 handlerAdded 事件并将其传递给包装的 HttpClientCodec。 HttpClientCodec 设置它的 inboundCtx 和 outboundCtx 并通过设置 handlerAdded=true 记录它已经被添加。
然后ProxyHandler.handlerAdded发现ctx.channel().isActive为false，什么都不做
ProxyHandler.channelActive 事件永远不会被触发，ProxyHandler.connect 永远不会被调用。相反，我的 netty 管道告诉我它无法连接到目标主机。
我做错了什么？