Net::HTTP

What Is This Library?

This library provides your program functions to access WWW documents via HTTP, Hyper Text Transfer Protocol version 1.1. For details of HTTP, refer [RFC2616] (http://www.ietf.org/rfc/rfc2616.txt).

Examples

Getting Document From WWW Server

Example #1: Simple GET+print

    require 'net/http'
    Net::HTTP.get_print 'www.example.com', '/index.html'

Example #2: Simple GET+print by URL

    require 'net/http'
    require 'uri'
    Net::HTTP.get_print URI.parse('http://www.example.com/index.html')

Example #3: More generic GET+print

    require 'net/http'
    require 'uri'

    url = URI.parse('http://www.example.com/index.html')
    res = Net::HTTP.start(url.host, url.port) {|http|
      http.get('/index.html')
    }
    puts res.body

Example #4: More generic GET+print

    require 'net/http'

    url = URI.parse('http://www.example.com/index.html')
    req = Net::HTTP::Get.new(url.path)
    res = Net::HTTP.start(url.host, url.port) {|http|
      http.request(req)
    }
    puts res.body

Posting Form Data

    require 'net/http'
    require 'uri'

    #1: Simple POST
    res = Net::HTTP.post_form(URI.parse('http://www.example.com/search.cgi'),
                              {'q'=>'ruby', 'max'=>'50'})
    puts res.body

    #2: POST with basic authentication
    res = Net::HTTP.post_form(URI.parse('http://jack:pass@www.example.com/todo.cgi'),
                                        {'from'=>'2005-01-01', 'to'=>'2005-03-31'})
    puts res.body

    #3: Detailed control
    url = URI.parse('http://www.example.com/todo.cgi')
    req = Net::HTTP::Post.new(url.path)
    req.basic_auth 'jack', 'pass'
    req.set_form_data({'from'=>'2005-01-01', 'to'=>'2005-03-31'}, ';')
    res = Net::HTTP.new(url.host, url.port).start {|http| http.request(req) }
    case res
    when Net::HTTPSuccess, Net::HTTPRedirection
      # OK
    else
      res.error!
    end

Accessing via Proxy

Net::HTTP.Proxy creates http proxy class. It has same methods of Net::HTTP but its instances always connect to proxy, instead of given host.

    require 'net/http'

    proxy_addr = 'your.proxy.host'
    proxy_port = 8080
            :
    Net::HTTP::Proxy(proxy_addr, proxy_port).start('www.example.com') {|http|
      # always connect to your.proxy.addr:8080
            :
    }

Since Net::HTTP.Proxy returns Net::HTTP itself when proxy_addr is nil, there’s no need to change code if there’s proxy or not.

There are two additional parameters in Net::HTTP.Proxy which allow to specify proxy user name and password:

    Net::HTTP::Proxy(proxy_addr, proxy_port, proxy_user = nil, proxy_pass = nil)

You may use them to work with authorization-enabled proxies:

    require 'net/http'
    require 'uri'

    proxy_host = 'your.proxy.host'
    proxy_port = 8080
    uri = URI.parse(ENV['http_proxy'])
    proxy_user, proxy_pass = uri.userinfo.split(/:/) if uri.userinfo
    Net::HTTP::Proxy(proxy_host, proxy_port,
                     proxy_user, proxy_pass).start('www.example.com') {|http|
      # always connect to your.proxy.addr:8080 using specified username and password
            :
    }

Note that net/http never rely on HTTP_PROXY environment variable. If you want to use proxy, set it explicitly.

Following Redirection

    require 'net/http'
    require 'uri'

    def fetch(uri_str, limit = 10)
      # You should choose better exception.
      raise ArgumentError, 'HTTP redirect too deep' if limit == 0

      response = Net::HTTP.get_response(URI.parse(uri_str))
      case response
      when Net::HTTPSuccess     then response
      when Net::HTTPRedirection then fetch(response['location'], limit - 1)
      else
        response.error!
      end
    end

    print fetch('http://www.ruby-lang.org')

Net::HTTPSuccess and Net::HTTPRedirection is a HTTPResponse class. All HTTPResponse objects belong to its own response class which indicate HTTP result status. For details of response classes, see section "HTTP Response Classes".

Basic Authentication

    require 'net/http'

    Net::HTTP.start('www.example.com') {|http|
      req = Net::HTTP::Get.new('/secret-page.html')
      req.basic_auth 'account', 'password'
      response = http.request(req)
      print response.body
    }

HTTP Request Classes

Here is HTTP request class hierarchy.

  Net::HTTPRequest
      Net::HTTP::Get
      Net::HTTP::Head
      Net::HTTP::Post
      Net::HTTP::Put
      Net::HTTP::Proppatch
      Net::HTTP::Lock
      Net::HTTP::Unlock
      Net::HTTP::Options
      Net::HTTP::Propfind
      Net::HTTP::Delete
      Net::HTTP::Move
      Net::HTTP::Copy
      Net::HTTP::Mkcol
      Net::HTTP::Trace

HTTP Response Classes

Here is HTTP response class hierarchy. All classes are defined in Net module.

  HTTPResponse
      HTTPUnknownResponse
      HTTPInformation                    # 1xx
          HTTPContinue                       # 100
          HTTPSwitchProtocl                  # 101
      HTTPSuccess                        # 2xx
          HTTPOK                             # 200
          HTTPCreated                        # 201
          HTTPAccepted                       # 202
          HTTPNonAuthoritativeInformation    # 203
          HTTPNoContent                      # 204
          HTTPResetContent                   # 205
          HTTPPartialContent                 # 206
      HTTPRedirection                    # 3xx
          HTTPMultipleChoice                 # 300
          HTTPMovedPermanently               # 301
          HTTPFound                          # 302
          HTTPSeeOther                       # 303
          HTTPNotModified                    # 304
          HTTPUseProxy                       # 305
          HTTPTemporaryRedirect              # 307
      HTTPClientError                    # 4xx
          HTTPBadRequest                     # 400
          HTTPUnauthorized                   # 401
          HTTPPaymentRequired                # 402
          HTTPForbidden                      # 403
          HTTPNotFound                       # 404
          HTTPMethodNotAllowed               # 405
          HTTPNotAcceptable                  # 406
          HTTPProxyAuthenticationRequired    # 407
          HTTPRequestTimeOut                 # 408
          HTTPConflict                       # 409
          HTTPGone                           # 410
          HTTPLengthRequired                 # 411
          HTTPPreconditionFailed             # 412
          HTTPRequestEntityTooLarge          # 413
          HTTPRequestURITooLong              # 414
          HTTPUnsupportedMediaType           # 415
          HTTPRequestedRangeNotSatisfiable   # 416
          HTTPExpectationFailed              # 417
      HTTPServerError                    # 5xx
          HTTPInternalServerError            # 500
          HTTPNotImplemented                 # 501
          HTTPBadGateway                     # 502
          HTTPServiceUnavailable             # 503
          HTTPGatewayTimeOut                 # 504
          HTTPVersionNotSupported            # 505

Switching Net::HTTP versions

You can use net/http.rb 1.1 features (bundled with Ruby 1.6) by calling HTTP.version_1_1. Calling Net::HTTP.version_1_2 allows you to use 1.2 features again.

    # example
    Net::HTTP.start {|http1| ...(http1 has 1.2 features)... }

    Net::HTTP.version_1_1
    Net::HTTP.start {|http2| ...(http2 has 1.1 features)... }

    Net::HTTP.version_1_2
    Net::HTTP.start {|http3| ...(http3 has 1.2 features)... }

This function is NOT thread-safe.