WebSphere HTTP Request Flow

The flow between components in response to a request from an internet browser.

1. An HTTP request is directed to the Servlet Engine by the WebSphere Application Server plug-in.
2. The request is executed in its own thread. The Servlet Engine dispatches the request to the HTTP Request Servlet.
3. The HTTP Request Servlet passes the request to the HTTP Adapter Manager.
4. The HTTP Adapter Manager determines that the request originated from an Internet browser. Therefore, it passes the request to the HTTP Browser Adapter.
5. The HTTP Browser Adapter passes the request to the Web controller.
6. The Web controller determines which command to invoke by querying the command registry.
7. Assuming that the request requires the use of a controller command, the Web controller invokes the appropriate controller command (the other option to invoke a view command). The controller command may access the database, using one or more entity beans.
8. After a controller command begins execution, there are a few possible paths:
    – The controller command may access the database using access beans and their corresponding entity beans.
    – The controller command may invoke one or more task commands.
    – The task commands may access the database, using access beans and their corresponding entity beans.
9. Upon completion, the controller command returns the name of a view command to the Web controller.
10.The Web controller looks up the view name struts config file. It invokes the view command implementation that is registered for the device type of the requester.
11.The view command forwards the request to a display template.
12.Within the JSP template, a data bean is required to retrieve dynamic information from the database. The data bean manager activates the data bean.
13.The data bean manager invokes a data bean command, if required.
14.The access bean from which the data bean is extended accesses the database using its corresponding entity bean.