为什么Firefox没有尊重分块传输编码？

Question

我正在通过在Apache Tomcat/6.0.18上运行的Spring MVC控制器传输大型文档

因为它很大,并且(最终)会动态生成,所以我决定使用分块传输编码.

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.inject.Inject;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.httpclient.ChunkedOutputStream;
import org.apache.commons.net.io.CopyStreamException;
import org.apache.commons.net.io.Util;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class QueryController {  

    @Inject
    QueryService queryService;

    @RequestMapping(value = "/stream")
    public void hellostreamer(HttpServletResponse response) throws CopyStreamException, IOException  {

        response.setHeader("Transfer-Encoding", "chunked");     
        response.setHeader("Content-type", "text/xml");
        InputStream filestream = new FileInputStream("/lotsrecs.xml");      
        ChunkedOutputStream chunkStream = new ChunkedOutputStream(response.getOutputStream());      
        Util.copyStream(filestream,chunkStream);
        chunkStream.close();
        chunkStream.finish();
    }
}

但是,当我在firefox中打开它时,我得到了这个:

XML Parsing Error: syntax error
Location: http://localhost:8082/streaming-mockup-1.0-SNAPSHOT/stream
Line Number 1, Column 1:

800
^

而不是将块大小作为关于流的元数据读取,而是将它们作为流的一部分读取!

使用Live HTTP标头,我可以看到正在接收Transfer-Encoding标头:

HTTP/1.1 200 OK

Server: Apache-Coyote/1.1

Transfer-Encoding: chunked
Content-Type: text/xml

Date: Thu, 11 Aug 2011 18:08:07 GMT

所以我不知道为什么没有正确解释块大小.如果我使用wget发出请求,我也会在返回的文档中看到块大小的字符,所以不知何故它们没有被正确编码.任何人都知道为什么？

使用wireshark查看传输:(请注意,"800"在整个流中重复出现)请注意0x800 = 2048,这是ChunkedOutputStream类使用的默认chunksize.

GET /streaming-mockup-1.0-SNAPSHOT/stream HTTP/1.0    
User-Agent: Wget/1.12 (linux-gnu)    
Accept: */*    
Host: localhost:8082    
Connection: Keep-Alive

HTTP/1.1 200 OK    
Server: Apache-Coyote/1.1    
Transfer-Encoding: chunked    
Content-Type: text/xml    
Date: Thu, 11 Aug 2011 18:47:24 GMT    
Connection: close

800

<records>
  <REC>
    <FUID>412286284WOS1</FUID>
    <UID>WOS:000292284100013</UID>
    <static_data>
      <summary>
        <EWUID uid="WOS:000292284100013" year="2011">

如果我只是直接复制到输出流而不创建ChunkedOutputStream,我根本看不到块大小:

GET /streaming-mockup-1.0-SNAPSHOT/stream HTTP/1.0
User-Agent: Wget/1.12 (linux-gnu)
Accept: */*
Host: localhost:8082    
Connection: Keep-Alive

HTTP/1.1 200 OK    
Server: Apache-Coyote/1.1    
Transfer-Encoding: chunked    
Content-Type: text/xml    
Date: Thu, 11 Aug 2011 18:51:05 GMT    
Connection: close    

<records>
  <REC>
    <FUID>412286284WOS1</FUID>
    <UID>WOS:000292284100013</UID>
    <static_data>
      <summary>

那么我怎么知道这是否被分块？如果是的话,我不会看到块大小吗？

Answer 1

你确定你需要ChunkedOutputStream为自己构建一个吗？

我的理解(没有实践)是ServletResponse.getOutputStream()应该在适当的时候为你处理分块(比如,如果客户端不是HTTP 1.0,等等).如果是真的,实际上被发送的答复,将分块编码中块编码,当然浏览器知道大约只有这些层.

您是否尝试在网络中的某个位置运行服务器并使用Wireshark检查事务？

更新:

GET /streaming-mockup-1.0-SNAPSHOT/stream HTTP/1.0

HTTP/1.0客户端根本不需要理解分块编码(当然,因为该编码仅为1.1发明).