如何COM preSS JSON用gzip Rails中为Android？ [英] How to compress JSON with gzip in Rails for Android?

问题描述

我从SQLite数据库上运行的Rails 3.2.7和Ruby 1.9.3p194输出JSON数据。

I am running Rails 3.2.7 with Ruby 1.9.3p194 to output JSON data from an SQLite database.

render :json => result.to_json

这是Android的应用程序使用它获取通过 HTTP-GET 加载的JSON文件：

An Android application consumes the JSON file which gets loaded via HTTP-GET:

HttpClient httpclient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(urlPath);
HttpResponse response = httpclient.execute(httpGet);
HttpEntity entity = response.getEntity();
String result = EntityUtils.toString(entity, HTTP.UTF_8);
JSONObject jsonObject = new JSONObject(result);

平台支持：

我读到的Rails API中提供的gzip支持如下：

ActiveSupport::Gzip.compress(result)

我也想从 HTTP / 1.1，RFC2626，第14.3 的我可以配置HTTP请求头：

I also guess from HTTP/1.1, RFC2626, section 14.3 that I can configure the header of a HTTP request:

httpPost.setHeader("Accept-Encoding", "gzip");

我还发现，包含在 3.5节内容值编码的信息很有趣：

  
• 所有内容编码值的区分大小写
  
• 在HTTP / 1.1使用在接受编码（第14.3）和内容编码（第14.11）头字段内容编码值。
  
• 在互联网编号分配机构（IANA）充当注册表内容编码值符号。最初，注册表包含的   以下标记：   
    
  • GZIP 作为在RFC 1952年[25]描述的文件COM pression计划的gzip（GNU的zip）产生的编码格式。
    

  • All content-coding values are case-insensitive.
  • HTTP/1.1 uses content-coding values in the Accept-Encoding (section 14.3) and Content-Encoding (section 14.11) header fields.
  • The Internet Assigned Numbers Authority (IANA) acts as a registry for content-coding value tokens. Initially, the registry contains the following tokens:
    • gzip An encoding format produced by the file compression program "gzip" (GNU zip) as described in RFC 1952 [25].

  这篇文章进一步解释如何处理GZIP EN $ C $镉含量与Android 。

  因此​​，我不知道，我怎么能找到，如果数据已经融为一体$ P $服务器pssed。 为了测试，无论是Rails的输出GZIP，我试图用的卷曲的的建议这里：

  Thus, I have no clue, how I can find out, if the data has been compressed by the server. To test, whether Rails outputs gzip, I tried to use curl as suggested here:

  $ curl --head -H "Accept-Encoding: gzip" http://localhost:3000/posts.json
  

  输出，但是，不会透露给我，GZIP是否支持或不：

  The output, however, does not reveal to me, whether gzip is supported or not:

  HTTP/1.1 200 OK 
  Content-Type: application/json; charset=utf-8
  X-Ua-Compatible: IE=Edge
  Etag: "f6f6732c747466f75052f88b1eff393b"
  Cache-Control: max-age=0, private, must-revalidate
  X-Request-Id: 74ee0562c05adea679deb701f1b8fd88
  X-Runtime: 0.004205
  Content-Length: 0
  Server: WEBrick/1.3.1 (Ruby/1.9.3/2012-04-20)
  Date: Thu, 16 Aug 2012 23:33:25 GMT
  Connection: Keep-Alive
  

  我也试过 - 中的参数=htt​​p://curl.haxx.se/docs/manpage.html >的卷曲的 ...

  I also tried the --compressed parameter of curl ...

  $ curl --compressed --head -H "Accept-Encoding: gzip" http://localhost:3000/posts.json
  

  它输出相同的头信息作为previous命令。当我运行...

  which outputs the same header information as the previous command. When I run ...

  $ curl --compressed -H "Accept-Encoding: gzip" http://localhost:3000/posts.json
  

  JSON数据被打印到控制台为可读文本。我看不到，如果COM pression发生。也许，因为卷曲的已经DECOM presses响应？！

  the JSON data is printed to the console as readable text. I cannot see if compression has happened. Maybe, because curl already decompresses the response?!

  我也尝试了在线测试 HTTP的COM pression测试的提到的<一个HREF =htt​​p://webmasters.stackexchange.com/a/543>此处。据证实，JSON内容是不是gzip压缩。第二个网站 GIDZipTest 联的此处承认的负面测试结果。

  I also tried the online test HTTP Compression Test mentioned here. It confirmed that the JSON content "is not gzipped". The second website GIDZipTest linked here acknowledged the negative test result.

  1. 如何输出的gzip COM pressed JSON从Rails的？
  2. 如何配置HTTP客户端请求的gzip COM pressed数据？
  3. 是否相同的配置仍然可以工作，当我在Heroku（PostgreSQL系统）运行Rails服务器，...？

  当我学会了所有我必须配置为REST服务器使用机架:: Deflater 。需要明确的是：我不使用的ActiveSupport :: Gzip.com preSS（）在我的code。如果有人有兴趣，这是头看起来当GZIP COM pression启用等。

  ---

  Lessons learned

  As I learned all I have to configure for the REST server is use Rack::Deflater. To be clear: I do not use ActiveSupport::Gzip.compress() in my code. In case someone is interested, this is what the header looks like when GZIP compression is enabled.

  HTTP/1.1 200 OK 
  Content-Type: application/json; charset=utf-8
  X-Ua-Compatible: IE=Edge
  Etag: "8170a04be41673bf25824256740a9460"
  Cache-Control: max-age=0, private, must-revalidate
  X-Request-Id: 700b9536f6a20164d31b8528bde423af
  X-Runtime: 0.369337
  Vary: Accept-Encoding
  Content-Encoding: gzip
  Server: WEBrick/1.3.1 (Ruby/1.9.3/2012-04-20)
  Date: Tue, 21 Aug 2012 12:10:48 GMT
  Content-Length: 20
  Connection: Keep-Alive
  

  现在我知道了神奇的关键字很容易搜索并找到使用机架:: Deflater 。

  Now that I know the magic keyword it is easy to search and find articles on use Rack::Deflater.

  推荐答案

  也许你应该使用机架:: Deflater？ 插入config.ru：

  maybe you should use Rack::Deflater? insert in config.ru:

  require ::File.expand_path('../config/environment',  __FILE__)
  use Rack::Deflater
  run MyAppName::Application
  

  和配置HTTP请求头：

  and configure your http request headers:

  我可以配置HTTP请求头：

  I can configure the header of a HTTP request:

  httpPost.setHeader（接受编码，GZIP）;

  httpPost.setHeader("Accept-Encoding", "gzip");

  P.S。相同的配置工作在Heroku

  P.S. the same configuration works on Heroku

  这篇关于如何COM preSS JSON用gzip Rails中为Android？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！