July 30, 2023

tHttpRequest – Docs for ESB 7.x

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tHttpRequest

Sends an HTTP request to the server and outputs the response information
locally.

tHttpRequest sends an HTTP request to the server end and
gets the corresponding response information from the server end.

tHttpRequest Standard properties

These properties are used to configure tHttpRequest running in the Standard Job framework.

The Standard
tHttpRequest component belongs to the Internet family.

The component in this framework is available in all Talend
products.

Basic settings

Schema and Edit Schema

A schema is a row description, it defines the number of fields to be
processed and passed on to the next component. The schema is either
Built-in or stored remotely in the
Repository.

Click Edit
schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

  • View schema: choose this
    option to view the schema only.

  • Change to built-in property:
    choose this option to change the schema to Built-in for local changes.

  • Update repository connection:
    choose this option to change the schema stored in the repository and decide whether
    to propagate the changes to all the Jobs upon completion. If you just want to
    propagate the changes to the current Job, you can select No upon completion and choose this schema metadata
    again in the Repository Content
    window.

 

Built-in: You create and store the
schema locally for this component only. Related topic: see

Talend Studio User Guide.

 

Repository: You have already created
the schema and stored it in the Repository. You can reuse it in various projects and Job
designs. Related topic: see
Talend Studio User
Guide.

Sync columns

Click this button to retrieve the schema from the preceding
component.

URI

Type in the Uniform Resource Identifier (URI) that identifies the data
resource on the server. A URI is similar to a URL, but more
general.

Method

Select an HTTP method to define the action to be performed:

Post: Sends data (for example HTML form
data) to the server end.

Get: Retrieves data from the server
end.

Post parameters from file

Browse to, or enter the path to the file that is used to provide
parameters (request body) to the POST method.

Write response content to file

Select this check box to save the HTTP response to a local file. You
can either type in the file path in the input field or click the
three-dot button to browse to the file path.

Create directory if not exists

Select this check box to create the directory defined in the Write response content to file field if it
does not exist.

This check box appears only when the Write
response content to file check box is selected and is
cleared by default.

Headers

Type in the name-value pair(s) for HTTP headers to define the
parameters of the requested HTTP operation.

Key: Fill in the name of the header
field of an HTTP header.

Value: Fill in the content of the
header field of an HTTP header.

For more information about definition of HTTP headers, please refer
to:

en.wikipedia.org/wiki/List_of_HTTP_headers.

Need authentication

Select this check box to fill in a user name and a password in the
corresponding fields if authentication is needed:

user: Fill in the user name for the
authentication.

password: Fill in the password for the
authentication.

To enter the password, click the […] button next to the
password field, and then in the pop-up dialog box enter the password between double quotes
and click OK to save the settings.

Die on error

Select the check box to stop the execution of the Job when an error
occurs.

Clear the check box to skip any rows on error and complete the
process for error-free rows.

Advanced settings

Set timeout

Select this check box to specify the connect and read timeout values
in the following two fields:

  • Connect timeout(s): Enter
    the connect timeout value in seconds. An exception will
    occur if the timeout expires before the connection can be
    established. The value of 0 indicates an infinite time out. By
    default, the connect timeout value is 30.

  • Read timeout(s): Enter
    the read timeout value in seconds. An exception will occur
    if the timeout expires before there is data available for
    read. By default, the read timeout value is 0, which indicates an infinite
    time out.

tStatCatcher Statistics

Select this check box to gather the Job processing metadata at a Job
level and at each component level.

Global Variables

Global Variables

ERROR_MESSAGE: the error message generated by the
component when an error occurs. This is an After variable and it returns a string. This
variable functions only if the Die on error check box is
cleared, if the component has this check box.

CONNECTED: the result of whether a connection to the
server established. This is an After variable and it returns a boolean.

RESPONSE_CODE: the response code returned by the remote
HTTP server. This is an After variable and it returns an integer.

A Flow variable functions during the execution of a component while an After variable
functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl +
Space to access the variable list and choose the variable to use from it.

For further information about variables, see
Talend Studio

User Guide.

Usage

Usage rule

This component can be used in sending HTTP requests to server and
saving the response information. This component can be used as a
standalone component.

Sending a HTTP request to the server and saving the response information
to a local file

This scenario describes a two-component Job that uses the GET method to retrieve information from the server end and writes the
response to a local file as well as to the console.

Linking the components

  1. In the
    Integration
     perspective
    of the Studio, create a Job from the Job
    Designs     node in the Repository tree view.

    For further information about how to create a Job, see the
    Talend Studio User Guide    .
  2. Drop the following components from the Palette onto the design workspace: tHttpRequest and tLogRow.

    tHttpRequest_1.png

  3. Connect the tHttpRequest component to
    the tLogRow component using a Row > Main
    connection.

Configuring the GET request

  1. Double-click the tHttpRequest component
    to open its Basic settings view and define
    the component properties.

    tHttpRequest_2.png

  2. Fill in the URI field with
    “http://192.168.0.63:8081/testHttpRequest/build.xml”.
    Note that this URI is for demonstration purposes only and it is not a live
    address.
  3. From the Method list, select GET.
  4. Select the Write response content to
    file     check box and fill in the input field on the right with
    the file path by manual entry, D:/test.txt for this use
    case.
  5. Select the Need authentication check box
    and fill in the user and password, both tomcat in this
    use case.

Executing the Job

Then you can run this Job.

The tLogRow component is used to present the
execution result of the Job.

  1. If you want to configure how the result is presented by tLogRow, double-click the component to open its
    Component view and in the Mode area, select the Table
    (print values in cells of a table)     check box.
  2. Press F6 to run this Job.

Once done, the response information from the server is saved and displayed.

tHttpRequest_3.png

Sending a POST request from a local JSON file

In this scenario, a four-component Job is used to read parameters from a given JSON
file and send it in a POST request to a web site.

tHttpRequest_4.png
The JSON file to be used reads as follows:

From that file, tFileInputJSON reads the e parameter and its value hello and tHttpRequest sends the pair
to http://echo.itcuties.com/, an URL provided for
demonstration by an online programming community, www.itcuties.com.

Note that the e parameter is required by http://echo.itcuties.com/.

Linking the components

  1. In the
    Integration
     perspective
    of the Studio, create an empty Job, named httpRequestPostDemo for example, from the Job Designs node in the Repository tree view.

    For further information about how to create a Job, see the
    Talend Studio User Guide    .
  2. Drop tFileInputJSON, tFileOutputDelimited, tHttpRequest and tLogRow
    onto the workspace.
  3. Connect tFileInputJSON to tHttpRequest using the Trigger > On Subjob Ok link.
  4. Connect the other components using the Row >
    Main     link.

Reading the JSON file

  1. Double-click tFileInputJSON to open its
    Component view.

    tHttpRequest_5.png

  2. Select JsonPath without loop from the
    Read By drop-down list.
  3. Click the […] button next to Edit schema to open the schema editor.

    tHttpRequest_6.png

  4. Click the [+] button to add one row and name
    it, for example, to data.
  5. Click OK to validate these changes and accept
    the propagation prompted by the pop-up dialog box.
  6. In the Filename field, browse, or enter the
    path to the source JSON file in which the parameter to be sent is stored.
  7. In the Mapping table, the data column you defined in the previous step in the
    component schema has been automatically added. In the JSONPath query column of this table, enter the JSON path, in
    double quotation marks, to extract the parameter to be sent. In this scenario,
    the path is echo[0].data.

Writing the parameter to a flat file

  1. Double-click tFileOutputDelimited to open
    its Component view.

    tHttpRequest_7.png

  2. In the File name field, browse, or enter
    the path to the flat file in which you want to write the extracted
    parameter. This file will be created if it does not exist. In this example,
    it is C:/tmp/postParamsFile.txt.

Posting the parameter

  1. Double-click tHttpRequest to open its
    Component view.

    tHttpRequest_8.png

  2. In the URI field, enter the server
    address to which the parameter is to be sent. In this scenario, it is
    http://echo.itcuties.com/.
  3. From the Method list, select POST.
  4. In the Post parameters from file field,
    browse, or enter the path to the flat file that contains the parameter to be
    used. As defined earlier with the tFileOutputDelimited component, this path is C:/tmp/postParamsFile.txt.

Executing the Job

Press F6 to run this Job.

The tLogRow component is used to present the
execution result of the Job.

Once done, the Run view is opened automatically,
where you can check the execution result.

tHttpRequest_9.png

You can read that the site receiving the parameter returns answers.

Document get from Talend https://help.talend.com
Thank you for watching.
Docs 7.x
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