保持客戶端關閉連接到一個netty服務器（有什麼我需要設置）？

Question

我正在調試我正在編寫的netty代理的一個問題，我注意到即使我跳過「代理」方面並實現一個簡單的http服務器並從commons httpclient串行發送兩個請求，公共https httpclient關閉連接，第二個請求在不同的連接中進行。如果我代理請求的另一方面，第二個請求使用相同的連接，但當我嘗試將第二個請求的響應寫入客戶端的通道時，我會收到'連接重置'異常。

代碼爲我的管道和基本的處理程序：

ChannelFactory factory = 
      new NioServerSocketChannelFactory(
        Executors.newCachedThreadPool(), 
        Executors.newCachedThreadPool()); 
    ServerBootstrap sb = new ServerBootstrap(factory); 

    sb.setPipelineFactory(new ChannelPipelineFactory() { 
     public ChannelPipeline getPipeline() { 
      return Channels.pipeline(
        new HttpRequestDecoder(), 
        new HttpResponseEncoder(), 
        new RequestHandler()); 
     } 
    }); 

private static class RequestHandler extends SimpleChannelHandler { 

    @Override 
    public void messageReceived(ChannelHandlerContext ctx, final MessageEvent e) { 
     HttpResponse clientResponse = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK); 
     clientResponse.setHeader(HttpHeaders.Names.CONTENT_TYPE, "text/html; charset=UTF-8"); 
     clientResponse.setContent(ChannelBuffers.wrappedBuffer(new byte[] {1, 2, 3})); 
     System.out.println("here: " + e.getChannel()); 
     e.getChannel().write(clientResponse); 
    } 
} 

這裏是在端口2080顯示客戶端關閉連接（開放式握手，推，推，近距離握手，開放式的握手，推tcpdump的，推，近距離握手）：

[master] sudo tcpdump -i any '(port 2080)' 
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode 
listening on any, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes 
15:13:22.396482 IP localhost.localdomain.45724 > localhost.localdomain.autodesk-nlm: Flags [S], seq 3122841582, win 32792, options [mss 16396,sackOK,TS val 880723828 ecr 0,nop,wscale 7], length 0 
15:13:22.396499 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.45724: Flags [S.], seq 604436385, ack 3122841583, win 32768, options [mss 16396,sackOK,TS val 880723829 ecr 880723828,nop,wscale 7], length 0 
15:13:22.396511 IP localhost.localdomain.45724 > localhost.localdomain.autodesk-nlm: Flags [.], ack 1, win 257, options [nop,nop,TS val 880723829 ecr 880723829], length 0 
15:13:22.406805 IP localhost.localdomain.45724 > localhost.localdomain.autodesk-nlm: Flags [P.], seq 1:1600, ack 1, win 257, options [nop,nop,TS val 880723839 ecr 880723829], length 1599 
15:13:22.406817 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.45724: Flags [.], ack 1600, win 256, options [nop,nop,TS val 880723839 ecr 880723839], length 0 
15:13:22.446068 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.45724: Flags [P.], seq 1:63, ack 1600, win 256, options [nop,nop,TS val 880723878 ecr 880723839], length 62 
15:13:22.446083 IP localhost.localdomain.45724 > localhost.localdomain.autodesk-nlm: Flags [.], ack 63, win 257, options [nop,nop,TS val 880723878 ecr 880723878], length 0 
15:13:22.449192 IP localhost.localdomain.45724 > localhost.localdomain.autodesk-nlm: Flags [F.], seq 1600, ack 63, win 257, options [nop,nop,TS val 880723881 ecr 880723878], length 0 
15:13:22.449360 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.45724: Flags [F.], seq 63, ack 1601, win 256, options [nop,nop,TS val 880723881 ecr 880723881], length 0 
15:13:22.449371 IP localhost.localdomain.45724 > localhost.localdomain.autodesk-nlm: Flags [.], ack 64, win 257, options [nop,nop,TS val 880723881 ecr 880723881], length 0 
15:13:22.449716 IP localhost.localdomain.35737 > localhost.localdomain.autodesk-nlm: Flags [S], seq 929672323, win 32792, options [mss 16396,sackOK,TS val 880723882 ecr 0,nop,wscale 7], length 0 
15:13:22.449729 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.35737: Flags [S.], seq 1626218986, ack 929672324, win 32768, options [mss 16396,sackOK,TS val 880723882 ecr 880723882,nop,wscale 7], length 0 
15:13:22.449737 IP localhost.localdomain.35737 > localhost.localdomain.autodesk-nlm: Flags [.], ack 1, win 257, options [nop,nop,TS val 880723882 ecr 880723882], length 0 
15:13:22.449986 IP localhost.localdomain.35737 > localhost.localdomain.autodesk-nlm: Flags [P.], seq 1:1600, ack 1, win 257, options [nop,nop,TS val 880723882 ecr 880723882], length 1599 
15:13:22.449992 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.35737: Flags [.], ack 1600, win 256, options [nop,nop,TS val 880723882 ecr 880723882], length 0 
15:13:22.453566 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.35737: Flags [P.], seq 1:63, ack 1600, win 256, options [nop,nop,TS val 880723886 ecr 880723882], length 62 
15:13:22.453582 IP localhost.localdomain.35737 > localhost.localdomain.autodesk-nlm: Flags [.], ack 63, win 257, options [nop,nop,TS val 880723886 ecr 880723886], length 0 
15:13:22.475867 IP localhost.localdomain.35737 > localhost.localdomain.autodesk-nlm: Flags [F.], seq 1600, ack 63, win 257, options [nop,nop,TS val 880723908 ecr 880723886], length 0 
15:13:22.475998 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.35737: Flags [F.], seq 63, ack 1601, win 256, options [nop,nop,TS val 880723908 ecr 880723908], length 0 
15:13:22.476012 IP localhost.localdomain.35737 > localhost.localdomain.autodesk-nlm: Flags [.], ack 64, win 257, options [nop,nop,TS val 880723908 ecr 880723908], length 0 

這裏是如果我使用代理服務器，基本上保存來自messageReceived()通道發生了什麼，以及稍後查找該通道寫響應。請注意，這裏的通道不是封閉的，而是由客戶端復位，導致一個IOException「連接復位」：

[master] sudo tcpdump -i any '(port 2080)' 
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode 
listening on any, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes 
15:11:02.055316 IP localhost.localdomain.58266 > localhost.localdomain.autodesk-nlm: Flags [S], seq 1055230627, win 32792, options [mss 16396,sackOK,TS val 880583487 ecr 0,nop,wscale 7], length 0 
15:11:02.055333 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.58266: Flags [S.], seq 596566447, ack 1055230628, win 32768, options [mss 16396,sackOK,TS val 880583487 ecr 880583487,nop,wscale 7], length 0 
15:11:02.055344 IP localhost.localdomain.58266 > localhost.localdomain.autodesk-nlm: Flags [.], ack 1, win 257, options [nop,nop,TS val 880583487 ecr 880583487], length 0 
15:11:02.066169 IP localhost.localdomain.58266 > localhost.localdomain.autodesk-nlm: Flags [P.], seq 1:1600, ack 1, win 257, options [nop,nop,TS val 880583498 ecr 880583487], length 1599 
15:11:02.066188 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.58266: Flags [.], ack 1600, win 256, options [nop,nop,TS val 880583498 ecr 880583498], length 0 
15:11:02.071439 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.58266: Flags [P.], seq 1:1568, ack 1600, win 256, options [nop,nop,TS val 880583503 ecr 880583498], length 1567 
15:11:02.071450 IP localhost.localdomain.58266 > localhost.localdomain.autodesk-nlm: Flags [.], ack 1568, win 256, options [nop,nop,TS val 880583503 ecr 880583503], length 0 
15:11:02.076384 IP localhost.localdomain.58266 > localhost.localdomain.autodesk-nlm: Flags [P.], seq 1600:3199, ack 1568, win 256, options [nop,nop,TS val 880583508 ecr 880583503], length 1599 
15:11:02.080625 IP localhost.localdomain.autodesk-nlm > localhost.localdomain.58266: Flags [P.], seq 1568:3135, ack 3199, win 256, options [nop,nop,TS val 880583513 ecr 880583508], length 1567 
15:11:02.102018 IP localhost.localdomain.58266 > localhost.localdomain.autodesk-nlm: Flags [R.], seq 3199, ack 3135, win 256, options [nop,nop,TS val 880583534 ecr 880583513], length 0 

有我丟失的東西在我的處理程序，以保持客戶端從關閉連接？

編輯：讀取響應似乎導致連接重置消失和連接被正常拆除。任何想法爲什麼這個println在第二個請求後阻止連接重置？

httpClient.executeMethod(method); 
System.out.println(method.getResponseBodyAsString()); 

Answer 1

終於明白了這一點。有幾個問題。最重要的問題是我沒有從公共HttpClient調用method.releaseConnection（）來啓動對這個代理的調用。出於某種原因，調用getResponseBodyAsString（）或getResponseBodyAsStream.close（）也消除了重置問題。

Answer 2

你的處理程序發送一個HTTP V1.1響應，其中保活是默認的連接類型，所以只要你的客戶期待V1.1和V1.0不，正確的行爲，那麼你不必再做任何事情來指示客戶保持連接的開放。

如果您的客戶端期望HTTP v1.0，您可以添加一個「Connection：keep-alive」標頭。