HTTP Client Output Adapter

The HTTP Client Output adapter sends data to an HTTP server using HTTP POST.

The adapter sends an HTTP POST request for every event in the stream to which it is attached. Specify the content of the HTTP request message body either in the adapter configuration or configure the adapter to obtain the message body content from a column in the attached stream. The adapter supports connecting to a proxy server, as well as HTTP basic authentication (user name/password). The URL for the HTTP server, user name, and password can be configured in a similar way to the message body content.

The adapter also supports HTTPS. To use HTTPS, ensure:

The provided URL starts with "https://..." instead of "http://...".
The HTTP server is using an SSL certificate that is trusted by the client. You may need to add the server's certificate to the Java CA certificates (cacerts) store using the Java "keytool" command. For example,
```
keytool -import -noprompt -trustcacerts -alias <AliasName> -file <certificate> -keystore <KeystoreFile> -storepass <Password>
```
Note that keytool is located in %ESP_HOME%\lib\jre\bin, <KeystoreFile> is located in %ESP_HOME%\lib\jre\lib\security\cacerts, and the default value for the <Password> is changeit.

See the Oracle Sun Java documentation for additional information regarding the cacerts file and keytool command. Once the certificate has been added, the adapter can connect to the HTTP server using HTTPS.

Commands specified in the cnxml file for this adapter cannot contain the following strings: "mv", "rm", or "del".

This adapter can run in managed or unmanaged mode.

Managed external adapters:

Are started and stopped by the ESP Server with an ESP project.
Have a cnxml adapter configuration file that is configured within the ESP Studio.
Are referenced in a CCL ATTACH ADAPTER statement.

Unmanaged external adapters:

Start and stop independently of the ESP Server and ESP projects.
Are configured independently.
Are not referenced in a CCL ATTACH ADAPTER statement.

Managed Mode Configuration
To start and stop the adapter with an ESP project, attach it to a project using the ATTACH ADAPTER statement and configure its properties using the ESP Studio.
Unmanaged Mode Configuration
To start and stop the adapter independently of an ESP project, do not reference it in an ATTACH ADAPTER statement, and configure it independently outside of the ESP Studio.
Starting the HTTP Client Adapter
Start the HTTP Client Output adapter either in unmanaged or managed mode. In unmanaged mode, the adapter is started separately from the ESP project, and in managed mode, the adapter is started with the ESP project. In unmanaged mode, you can start the adapter from the command line or using the start command files.
Stopping the HTTP Client Adapter
To stop the HTTP Client Output adapter from the command line, execute the stop command.
Adapter Controller Parameters
The Adapter Control port listens for commands. The controller.xml file is located in %ESP_HOME%/adapters/framework/config directory. This file is shared among all the adapters within the %ESP_HOME%/adapters/framework/instances directory.
Logging
The HTTP Client Output adapter use the Apache log4j API to log errors, warnings, and information and debugging messages. A sample log4j.properties file containing the logging configuration is located in the %ESP_HOME%\adapters\framework\config directory.

Parent topic: Adapters Currently Available from SAP