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 to [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

#4: Multiple values
res = Net::HTTP.post_form(URI.parse('http://www.example.com/search.cgi'),
                          {'q' => ['ruby', 'perl'], 'max' => '50'})
puts res.body

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
        HTTPSwitchProtocol                 # 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.

lib/net/http.rb