The HTTP transformation enables you to connect to an HTTP server to use its services and applications. The HTTP transformation is a passive transformation. When you run a session with an HTTP transformation, the Integration Service connects to the HTTP server and issues a request to retrieve data from or update data on the HTTP server, depending on how you configure the transformation:
Read data from an HTTP server.
When the Integration Service reads data from an HTTP server, it retrieves the data from the HTTP server and passes the data to the target or a downstream transformation in the mapping. For example, you can connect to an HTTP server to read current inventory data, perform calculations on the data during the PowerCenter session, and pass the data to the target.
Update data on the HTTP server.
When the Integration Service writes to an HTTP server, it posts data to the HTTP server and passes HTTP server responses to the target or a downstream transformation in the mapping. For example, you can post data providing scheduling information from upstream transformations to the HTTP server during a session.
The Integration Service passes data from upstream transformations or the source to the HTTP transformation, reads a URL configured in the HTTP transformation or application connection, and sends an HTTP request to the HTTP server to either read or update data.
Requests contain header information and may contain body information. The header contains information such as authentication parameters, commands to activate programs or web services residing on the HTTP server, and other information that applies to the entire HTTP request. The body contains the data the Integration Service sends to the HTTP server.
When the Integration Service sends a request to read data, the HTTP server sends back an HTTP response with the requested data. The Integration Service sends the requested data to downstream transformations or the target.
When the Integration Service sends a request to update data, the HTTP server writes the data it receives and sends back an HTTP response that the update succeeded. The HTTP transformation considers response codes 200, 201, and 202 as a success. The HTTP transformation considers all other response codes as failures. The session log displays an error when an HTTP server passes a response code that is considered a failure to the HTTP transformation. The Integration Service then sends the HTTP response to downstream transformations or the target.
You can configure the HTTP transformation for the headers of HTTP responses. HTTP response body data passes through the HTTPOUT output port.