Version

    HTTPConnector

    Short Description
    Ports
    Metadata
    HTTPConnector Attributes
    Details
    Examples
    Best Practices
    Compatibility
    See also

    Short Description

    HTTPConnector sends HTTP requests to a web server and receives responses. The request is written in a file or in the graph itself or it is received through a single input port. The response can be sent to an output port, stored to a specified file or stored to a temporary file. The path to the file can then be sent to a specified output port.

    ComponentSame input metadataSorted inputsInputsOutputsEach to all outputsJavaCTLAuto-propagated metadata
    HTTPConnector-
    no
    		0-10-2-
    no
    no
    yes

    Ports

    Port typeNumberRequiredDescriptionMetadata
    Input0
    no
    		For setting various attributes of the componentAny
    Output0
    no
    		For a response content, response file path, status code, component attributes...Any
    1
    no
    		For error detailsAny

    Metadata

    HTTPConnector does not propagate metadata.

    HTTPConnector has metadata templates on its ports available.

    You do not have to use metadata templates on input and output edges.

    See general details on metadata templates.

    Input

    Table 62.2. HTTPConnector_Request

    Field numberField nameData type
    1URLstring
    2requestMethodstring
    3addInputFieldsAsParametersboolean
    4addInputFieldsAsParametersTostring
    5ignoredFieldsstring
    6additionalHTTPHeaderPropertiesstring
    7charsetstring
    8requestContentstring
    9requestContentBytebyte
    10inputFileURLstring
    11outputFileURLstring
    12appendOutputboolean
    13authenticationMethodstring
    14usernamestring
    15passwordstring
    16consumerKeystring
    17consumerSecretstring
    18storeResponseToTempFileboolean
    19temporaryFilePrefixstring
    20multipartEntitiesstring
    21rawHTTPHeadesstring[]

    Output

    Table 62.3. HTTPConnector_Response

    Field numberField nameData typeDescription
    1contentstring

    The content of the HTTP response as a string. This field will be null, if the response is written to a file.

    2contentBytebyte

    The raw content of the HTTP response as an array of bytes. This field will be null, if the response is written to a file.

    3outputFilePathstring

    The path to a file, where the response has been written. Will be null, if the response is not written to a file.

    4statusCodeintegerAn HTTP status code of the response.
    5headermap[string,string]A map representing HTTP header properties from response.
    6rawHeadersstring[]
    7errorMesagestringAn error message, in case that the error output is redirected to a standard output port.

    Table 62.4. HTTPConnector_Error

    Field numberField nameData typeDescription
    1errorMessagestringError message

    HTTPConnector Attributes

    AttributeReqDescriptionPossible values
    Basic
    URL [1]

    A URL of the HTTP server the component connects to. May contain one or more placeholders in the following form: *{<field name>}. For the URL format, see Reading of Remote Files. The HTTP, HTTPS, FTP and SFTP protocols are supported. Connecting via a proxy server is available, too, for example: http:(proxy://proxyHost:proxyPort)//www.domain.com.

    		 
    Request method Method of request.GET (default) | POST | PUT | PATCH | DELETE | HEAD | OPTIONS | TRACE
    Add input fields as parameters 

    Specifies whether additional parameters from the input edge should be added to the URL. Note: When parameters are read from the input edge and put to the query string, they can contain special characters (?, @, :, etc.). Do not replace such characters with %-notation, HTTPConnector automatically makes them URL-encoded This feature was introduced in CloverDX 3.3-M3 and causes backwards incompatibility.

    		false (default) | true
    Send parameters in 

    Specifies whether input fields should be added to the query string or method body. Parameters can only be added to the method body in case that Request method is set to POST.

    		QUERY (default) | BODY
    Ignored fields 

    Specifies which input fields are not added as parameters. A list of input fields separated by a semicolon is expected.

    		 
    Additional HTTP headers 

    Additional properties of the request that will be sent to the Server. A dialog is used to create it, the final form is a sequence of key=value pairs separated by a comma and the whole sequence is surrounded by curly braces. The value may refer to a field or parameter using a ${fieldName} or ${parameterName} notation.

    		 
    Multipart entities 

    Specifies fields, that should be added as multipart entities to a POST request. Field name is used as an entity name. A list of input fields separated by a semicolon is expected.

    		 
    Request/response charset 

    Character encoding of the input/output files

    The default encoding depends on DEFAULT_CHARSET_DECODER in defaultProperties.

    		UTF-8 | other encoding
    Request content 

    The request content defined directly in a graph. Can also be specified as the Input file URL or using the requestContent or requestContentByte fields in the Input mapping.

    		 
    Input file URL 

    A URL of a file from which a single HTTP request is read. See URL File Dialog.

    		 
    Output file URL 

    A URL of a file to which an HTTP response is written. See URL File Dialog. The output files are not deleted automatically and must be removed manually or as a part of the transformation.

    		 
    Append output 

    By default, any new response overwrites the older one. If you switch this attribute to true, the new response is appended to the old ones. Is applied to output files only.

    		false (default) | true
    Input Mapping Allows to set various properties of the component by mapping their values from an input record. 
    Output Mapping 

    Allows to map response data (like a content, status code, etc. ) to the output record. It is also possible to map values from input fields and error details (if Redirect error output is set to true).

    		 
    Error Mapping 

    Allows to map an error message to the output record. It is also possible to map values from input fields and attributes.

    		 
    Redirect error output Allows to redirect error details to a standard output port.false (default) | true
    Advanced
    Raw HTTP Headers[2] Additional user-defined HTTP headers defined as text.e.g. Pragma: no-cache
    Request Cookies 

    Define cookies to be send in an HTTP request. The values of cookies can be set up in Input mapping.

    		 
    Response Cookies 

    Define names of response cookies to be used. The mapping can be set up in Output mapping. The names of particular cookies are separated by a semicolon.

    		E.g. cookie1;cookie2
    Authentication method Specifies which authentication method should be used.HTTP BASIC (default) | HTTP DIGEST | ANY
    Username A username required to connect to the server. 
    Password A password required to connect to the server. 
    OAuth Consumer key 

    A consumer key associated with a service. Defines the access token (2-legged OAuth) for signing requests - together with OAuth Consumer secret.

    		 
    OAuth Consumer secret 

    A consumer secret associated with a service. Defines the access token (2-legged OAuth) for signing requests - together with OAuth Consumer key.

    		 
    OAuth Access Token[3] An additional field used during OAuth authentication. 
    OAuth Access Token secret[3] An additional field used during OAuth authentication. 
    Store HTTP response to file[4]

    If this attribute is switched to true, a response is written to temporary files with a prefix specified in the Prefix for response names attribute. The path to these temporary files can be retrieved using Output Mapping. Storing a response to temporary files is necessary in case the response body is too large to be stored in a single string data field. The temporary files are deleted automatically after graph finishes (if it has not run in Debug mode).

    		false (default) | true
    Prefix for response files 

    A prefix that will be used in the name of each output file with an HTTP response. To this prefix, distinguishing numbers are appended.

    		"http-response-"

    (default)

    | other prefix
    Stream input file 

    If the request content is specified by the Input file URL attribute, the input file is uploaded using chunked transfer encoding.

    Set the attribute to false to disable streaming.

    		true (default) | false
    Request parameters 

    Set up a parameter that has a different name from the field name in the metadata. It enables usage of parameters having names that cannot be used as metadata field names (e.g start-date).

    		 
    Disable SSL Certificate Validation 

    Disables certificate validation of the page you are connecting to. Use this attribute only if you know, what you are doing. Available since CloverDX 4.1.0-M1.

    		 
    Timeout 

    How long the component waits to get a response. If it does not receive a response within a specified limit, the execution of the component fails. The HTTPConnector has no timeout by default.

    Timeout is in milliseconds. Different time units can be used. See Time Intervals.

    		0 (default) | E.g. 5000
    Retry Count 

    How many times should the component retry a request in the case of a failure.

    Note that the failure does not mean a response status code different from 2xx. A failure is meant same as when component uses error port. Component consider a failure if it cannot process the request/response, i.e. IOException. If it processes the request and gets response with an error status code (e.g. 500), it is not a failure.

    		0 (default)
    Deprecated
    URL from input field[1]

    The name of a string field specifying the target URL you wish to retrieve. The field value may contain placeholders in the form *{<field name>}. For the URL format, see Reading of Remote Files. The HTTP, HTTPS, FTP and SFTP protocols are supported.

    		 
    Input field[4]

    The name of the field of input metadata from which the request content is received. Must be of string data type. May be used for multi HTTP requests.

    		 
    Output field  The name of the field of output metadata to which the response content is sent. Must be of string data type. May be used for multi HTTP responses.  

    [1]  A URL must be specified by setting one of the URL or URL from field attributes or mapping it in the Input mapping.

    [2]  Available since release 3.3.

    [3]  Available since release 3.5.

    [4]  The response can be stored either in a file specified in Output file URL or in a temporary file (when Store response file URL to output field is set to true) - it is not possible to use both options.

    Details

    Input Mapping
    Multipart entities
    Output Mapping
    Error mapping

    Input Mapping

    Editing the Input mapping attribute opens the Transform Editor where you can decide which component attributes should be set using the input record.

    Transform Editor in HTTPConnector

    Figure 62.4. Transform Editor in HTTPConnector


    The dialog provides you with all the power and features known from Transform Editor and CTL.

    [Note]Note

    All kinds of CTL functions are available to modify the input field value to be used.

    Multipart entities

    Since CloverDX 3.5.4, you can set up multipart entities in the transform editor. Input mapping now offers new fields derived from the value of the Multipart entities attribute. For example, field1;field2 as the value of multipart entities generates the following fields.

    Multipart entities in input mapping

    Figure 62.5. Multipart entities in input mapping


    The generated fields can be used to control multipart entities.

    If you deal with Multipart entities, you have to use the POST method.

    Possible ways of configuration of multipart entities
    List of input fields
    Map content of multipart entity
    Map content and filename
    Use file as multipart entity
    List of input fields

    Compatible with previous versions. The Multipart entities attribute contains a semicolon separated list of fields from the input record. Each field is a multipart entity. The name is same as the field name, the field value is used as a content.

    Map content of multipart entity

    Use input mapping to set a content of multipart. The multipart name will be same as the fieldname and the content will be specified by a mapping.

    Map content and filename

    The multipart content will be used by the mapping, but there will be an additional multipart header in the request using the filename as mapped.

    Example 62.1. CTL Mapping and multipart entities

    The CTL mapping

    function integer transform() {
    $out.4.field1_EntityContent="My custom content";
    $out.4.field1_EntityFileNameAttribute="MyFilename";
    returnALL;
}

    produces following multipart content.

    ­­CB5PZVJDq5RyTWoZqxvtjlbVM0CrMa3Mt
Content­Disposition: form­data; name="field1"; filename="MyFilename"
Content­Type: text/plain; charset=UTF­8
Content­Transfer­Encoding: 8bit

My custom content
­­CB5PZVJDq5RyTWoZqxvtjlbVM0CrMa3Mt

    Use file as multipart entity

    To use files as multipart entities, map only the *_File field. Do not map the _Content field. 

    $out.3.field3_EntitySourceFile = "${PROJECT}/workspace.prm";

    This will upload the file workspace.prm as a multipart entity.

    ­­3xEKe3wUSOl2cRnjwh1UsPVnDOoL7D
Content­Disposition: form­data; name="field3"; filename="workspace.prm"
Content­Type: application/octet­stream
Content­Transfer­Encoding: binary

... [here is content of file]

­­3xEKe3wUSOl2cRnjwh1UsPVnDOoL7D­­

    The file can be specified by a URL similar to the fileURL attribute in readers. But it cannot use the port reading or dictionary reading.

    Output Mapping

    Editing the attribute opens the Transform Editor where you can decide what should be sent to an output port.

    Transform Editor in HTTPConnector

    Figure 62.6. Transform Editor in HTTPConnector


    The dialog provides you with all the power and features known from Transform Editor and CTL.

    To do the mapping in a few basic steps:

    1. Provided you already have some output metadata, just left-click an item in the left-hand pane and drag it onto an output field. This will send the result data to the output.

    2. If you do not have any output metadata:

      1. Drag a Field from the left pane and drop it into the right pane (an empty space).

      2. This produces a new field in the output metadata.

    You can map various data to the output port:

    • Values of fields from input metadata - you can send values from input fields to the output port. This is mainly useful, when you are using some kind of a session identifier for HTTP requests.

    • Result - provides result data. These includes:

      • content - the content of the HTTP response as a string. This field will be null if the response is written to a file.

      • contentByte - the raw content of the HTTP response as an array of bytes. This field will be null if the response is written to a file.

      • outputFilePath - the path to a file, where the response has been written. Will be null if the response is not written to a file.

      • statusCode - the HTTP status code of the response.

      • header - the map representing HTTP header properties from the response.

      • rawHeaders - headers of the response.

      • errorMessage - the error message in case that the error output is redirected to a standard output port.

    • Attributes - provides values of the component attributes:

      • URL - the URL where the request has been sent.

      • requestMethod - the method that was used for the request.

      • requestContent - the content of the request, that has been sent (if specified as a string).

      • inputFileUrl - a URL of the file containing the request content.

    [Note]Note

    Output mapping uses CTL (you can switch to the Source tab). All kinds of functions are available to modify the value to be stored in the output field. 

    $out.0.prices = find($in.1.content, "price: .*? USD")

    finds all occurrences of the form price: [some text] USD in the response content.

    If you let output mapping empty, the default output mapping is used:

    $out.0.* = $in.0.*;
$out.0.* = $in.1.*;

    The default mapping has been introduced in version 4.1.0.

    Error mapping

    Editing the Error mapping attribute opens the Transform Editor where you can map error details to an output port. The behavior is very similar to the Output mapping

    If you let error mapping empty, the default error mapping is used:

    $out.1.* = $in.0.*;
$out.1.* = $in.1.*;

    The default mapping has been introduced in version 4.1.0.

    Notes

    When the graph's log level is set to DEBUG, the HTTPConnector prints the HTTP request and response to graph log.

    Examples

    Downloading a Web Page
    Downloading Document Requiring HTTP Authentication
    Connecting via HTTP Proxy without Password
    Connecting via HTTP Proxy using Password
    Using OAuth in HTTPConnector
    Upload a File using Multipart Entities
    Using Connection Timeout and Retry Count

    Downloading a Web Page

    Download the content of the web page www.cloverdx.com using HTTPConnector. Save the result to the file for further processing.

    Solution

    Use the URL and Output file URL attributes. The downloaded page will be saved into the result.html file in the ${DATAOUT_DIR} directory.

    AttributeValue
    URLhttp://www.cloverdx.com/
    Output file URL${DATAOUT_DIR}/result.html

    Downloading Document Requiring HTTP Authentication

    Download a document from https://protected.example.org/document.html. The site requires HTTP basic authentication.

    Solution

    Set up the URL, Output file URL, Username and Password attributes. We suggest to use secure parameters to store your password.

    AttributeValue
    URLhttps://protected.example.org/document.html
    Output file URL${DATAOUT_DIR}/document.html
    UsernamemyUserName
    Password${PASSWORD}

    An alternative solution is to connect an edge to the first output port instead of filling the Output file URL attribute. The result will be send to the edge. No output mapping is necessary.

    Connecting via HTTP Proxy without Password

    Download the content of the page http://www.cloverdx.com/. The page is accessible via proxy on 10.0.3.5 listening on TCP port 3128.

    Solution

    Use the URL attribute. You can use Output file URL to write a result to a file, or connect an output edge.

    AttributeValue
    URLhttp:(proxy://10.0.3.5:3128)//www.cloverdx.com/
    Output file URL${DATAOUT_DIR}/result.html

    Note: The proxy may introduce some limitations. For example, it may deny you to connect via HTTPS, etc.

    Connecting via HTTP Proxy using Password

    The problem to be solved is similar to the previous example. The difference is that proxy requires a username (test) and password (securePassword).

    Solution
    AttributeValue
    URLhttp:(proxy://test:securePassword@10.0.3.5:3128)//www.cloverdx.com/
    Output file URL${DATAOUT_DIR}/result.html

    Using OAuth in HTTPConnector

    Connect to Twitter API and get some tweets about Java.

    Solution

    Use the URL, OAuth Consumer key, OAuth Consumer secret, OAuth Access Token and OAuth Access Token secret attributes.

    Connect an edge to the first output port to pass results by the edge or fill in the Output file URL attribute to write down results to a file.

    AttributeValue
    URLhttps://api.twitter.com/1.1/search/tweets.json?q=java&count=20
    OAuth Consumer keyyYjLhENks7mNlt7k4l2hKuHXP
    OAuth Consumer secretOE1dkaadjJR8LSOFFlakeH4YRlLkaiqnvVlSlAxZmNlrtoHpyI
    OAuth Access Token3062213700-IJNdsaG3e4vwUasoro4T5p5V2aOxEwYasvrlVs3
    OAuth Access Token secretS2hl7ivynvXI69kzky7Fx3ZJ84ZBCK6vt2G7bW3TFNTO7

    Note: The credentials in this example are not valid, you have to use your own credentials.

    Upload a File using Multipart Entities

    Send a file using multipart entities. The file content is available in field1 field.

    Solution

    Use the URL, Request method, Multipart entities and Input mapping attributes.

    AttributeValue
    URLhttp://www.example.com/
    Request methodPOST
    Add input fields as parameterstrue
    Multipart entitiesfield1
    Input mappingSee the code below
    function integer transform() {
    $out.4.field1_EntityContent = $in.0.field1;

    return ALL;
}

    Map multipart entities in the Input mapping dialog.

    Using Connection Timeout and Retry Count

    Connect to www.my-sometimes-responding-server.com which sometimes fails to respond. The response has to be returned within 20 seconds, otherwise connection should be considered as nonresponding. Make at most 5 attempts in total.

    Solution

    Use Timeout to set up time limit on connection to avoid waiting if server does not reply. If server responds sometimes only, use Retry count to ask several times.

    AttributeValue
    URLhttp://www.my-sometimes-responding-server.com/
    Request methodGET
    Timeout20s
    Retry count4

    Timeout is in milliseconds. If you need to set it in seconds, minutes, hours, etc., add the unit. See Time Intervals. Retry count set to 4 causes up to 4 additional retries (if necessary). At most five requests are performed in total.

    Best Practices

    We recommend users to explicitly specify Request/response charset.

    Compatibility

    VersionCompatibility Notice
    3.3.0-M3

    It is no longer necessary to encode field values used as Query parameters before passing them to HTTPConnector - they are encoded automatically. This, however, breaks backward compatibility, so be aware of this fact.

    It is now possible to use Output mapping to retrieve path to an output file, when the response is stored to a file (whether it is stored to temporary file or user-specified file). The file path is no longer sent to an output port automatically (as was the case for temporary files).

    3.5.4You can now map file as a multipart entity. You can map multipart entities in transform editor too.
    4.1.0-M1You can now disable SSL Certificate validation.
    4.1.0

    You can now set up Timeout and Retry count.

    Default output mapping or error mapping is now used if output mapping or error mapping is not defined.